TWIM issue

Hello ,
I am working on a project which contains I2C communication,
When I test the twi scanner example on my sensor and it works fine
But when I do the combination with the usbd_ble_uart example to send the data to uart I encountered a problem during an I2C read operation. My code stuck in this infinite loop

bool transmission_finished = false;
        do {
            if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_SUSPENDED))
            {
                transmission_finished = true;
            }

            if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_STOPPED))
            {
                nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_STOPPED);
                transmission_finished = true;
            }

            if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_ERROR))
            {
                nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_ERROR);

                bool lasttx_triggered = nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_LASTTX);
                uint32_t shorts_mask = nrf_twim_shorts_get(p_twim);

                if (!(lasttx_triggered && (shorts_mask & NRF_TWIM_SHORT_LASTTX_STOP_MASK)))
                {
                    // Unless LASTTX event arrived and LASTTX_STOP shortcut is active,
                    // triggering of STOP task in case of error has to be done manually.
                    nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_RESUME);
                    nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_STOP);

                    // Mark transmission as not finished yet,
                    // as STOPPED event is expected to arrive.
                    // If LASTTX_SUSPENDED shortcut is active,
                    // NACK has been received on last byte sent
                    // and SUSPENDED event happened to be checked before ERROR,
                    // transmission will be marked as finished.
                    // In such case this flag has to be overwritten.
                    transmission_finished = false;
                }

                if (lasttx_triggered && (shorts_mask & NRF_TWIM_SHORT_LASTTX_SUSPEND_MASK))
                {
                    // When STOP task was triggered just before SUSPEND task has taken effect,
                    // SUSPENDED event may not arrive.
                    // However if SUSPENDED arrives it always arrives after ERROR.
                    // Therefore SUSPENDED has to be cleared
                    // so it does not cause premature termination of busy loop
                    // waiting for STOPPED event to arrive.
                    nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_SUSPENDED);

                    // Mark transmission as not finished yet,
                    // for same reasons as above.
                    transmission_finished = false;
                }
            }
        } while (!transmission_finished);

Although I tried to copy all the configuration performed in the example of twi scanner

Please Help me .

  • Hello nikola,

    When I test the twi scanner example on my sensor and it works fine

    Thank you for clarifying this - then we know that there is no issue with your hardware connections. 

    But when I do the combination with the usbd_ble_uart example to send the data to uart I encountered a problem during an I2C read operation. My code stuck in this infinite loop

    Which priority are you using for your TWI and USBD IRQ's?
    The TWI peripheral examples does not have to account for the fact that it may be interrupted at any time (such as by the SoftDevice), so I suspect the issue here is that the TWI transfer or post-processing is being interrupted at an inopportune time, which causes it to get stuck in this loop. If this is the case, you will either have to change your tranmission_finished implementation, or add some sort of watchdog / timer / specific error handling to this loop, in order to break out if this occurs.
    Lets start by identifying exactly why it does wrong, and then look into what we may do to avoid it.

    Best regards,
    Karl

  • Thank you for answering me
    I solved this error
    but I have another problem concerning the execution of the two processes in the same while loop  when I put the two commands together in while (true) of main.c the sensor sends the data until a given moment and it stops the execution
    i want to know how i can run both codes in the same while loop

  • there is my main code :

    /**
    * Copyright (c) 2017 - 2020, Nordic Semiconductor ASA
    *
    * All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without modification,
    * are permitted provided that the following conditions are met:
    *
    * 1. Redistributions of source code must retain the above copyright notice, this
    * list of conditions and the following disclaimer.
    *
    * 2. Redistributions in binary form, except as embedded into a Nordic
    * Semiconductor ASA integrated circuit in a product or a software update for
    * such product, must reproduce the above copyright notice, this list of
    * conditions and the following disclaimer in the documentation and/or other
    * materials provided with the distribution.
    *
    * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
    * contributors may be used to endorse or promote products derived from this
    * software without specific prior written permission.
    *
    * 4. This software, with or without modification, must only be used with a
    * Nordic Semiconductor ASA integrated circuit.
    *
    * 5. Any software provided in binary form under this license must not be reverse
    * engineered, decompiled, modified and/or disassembled.
    *
    * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
    * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
    * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
    * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
    * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
    * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    */
    /** @file
    *
    * @defgroup usbd_ble_uart_example main.c
    * @{
    * @ingroup usbd_ble_uart_example
    * @brief USBD CDC ACM over BLE application main file.
    *
    * This file contains the source code for a sample application that uses the Nordic UART service
    * and USBD CDC ACM library.
    * This application uses the @ref srvlib_conn_params module.
    */

    #include <stdint.h>
    #include <string.h>
    #include "nordic_common.h"
    #include "nrf.h"
    #include "ble_hci.h"
    #include "ble_advdata.h"
    #include "ble_advertising.h"
    #include "ble_conn_params.h"
    #include "nrf_sdh.h"
    #include "nrf_sdh_soc.h"
    #include "nrf_sdh_ble.h"
    #include "nrf_ble_gatt.h"
    #include "app_timer.h"
    #include "ble_nus.h"
    #include "app_uart.h"
    #include "app_util_platform.h"
    #include "bsp_btn_ble.h"

    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"

    #include "nrf_drv_usbd.h"
    #include "nrf_drv_clock.h"
    #include "nrf_gpio.h"
    #include "nrf_delay.h"
    #include "nrf_drv_power.h"

    #include "app_error.h"
    #include "app_util.h"
    #include "app_usbd_core.h"
    #include "app_usbd.h"
    #include "app_usbd_string_desc.h"
    #include "app_usbd_cdc_acm.h"
    #include "app_usbd_serial_num.h"
    /*********************PPG Librairies ***********************/

    #include <stdint.h>
    #include <stdbool.h>
    #include "boards.h"
    #include "app_util_platform.h"
    #include "app_error.h"
    #include "nrf_drv_twi.h"
    #include "nrf_delay.h"
    #include "nrf.h"
    #include "nrf_drv_rtc.h"
    #include "nrf_drv_clock.h"
    #include "nrf_log.h"
    #include "nrf_log_ctrl.h"
    #include "nrf_log_default_backends.h"
    /*****************************End of PPG Librairies *****************/

    /**************************TWI initailisation of PPG ********************/
    /* TWI instance ID. */
    #if TWI0_ENABLED
    #define TWI_INSTANCE_ID 0
    #elif TWI1_ENABLED
    #define TWI_INSTANCE_ID 1
    #endif

    /* Number of possible TWI addresses. */
    #define TWI_ADDRESSES 127
    /************************** End of TWI initailisation of PPG ********************/


    #define LED_BLE_NUS_CONN (BSP_BOARD_LED_0)
    #define LED_BLE_NUS_RX (BSP_BOARD_LED_1)
    #define LED_CDC_ACM_CONN (BSP_BOARD_LED_2)
    #define LED_CDC_ACM_RX (BSP_BOARD_LED_3)

    #define LED_BLINK_INTERVAL 800

    APP_TIMER_DEF(m_blink_ble);
    APP_TIMER_DEF(m_blink_cdc);

    /**
    * @brief App timer handler for blinking the LEDs.
    *
    * @param p_context LED to blink.
    */
    void blink_handler(void * p_context)
    {
    bsp_board_led_invert((uint32_t) p_context);
    }

    #define ENDLINE_STRING "\r\n"

    // USB DEFINES START
    static void cdc_acm_user_ev_handler(app_usbd_class_inst_t const * p_inst,
    app_usbd_cdc_acm_user_event_t event);

    #define CDC_ACM_COMM_INTERFACE 0
    #define CDC_ACM_COMM_EPIN NRF_DRV_USBD_EPIN2

    #define CDC_ACM_DATA_INTERFACE 1
    #define CDC_ACM_DATA_EPIN NRF_DRV_USBD_EPIN1
    #define CDC_ACM_DATA_EPOUT NRF_DRV_USBD_EPOUT1

    static char m_cdc_data_array[BLE_NUS_MAX_DATA_LEN];

    /** @brief CDC_ACM class instance */
    APP_USBD_CDC_ACM_GLOBAL_DEF(m_app_cdc_acm,
    cdc_acm_user_ev_handler,
    CDC_ACM_COMM_INTERFACE,
    CDC_ACM_DATA_INTERFACE,
    CDC_ACM_COMM_EPIN,
    CDC_ACM_DATA_EPIN,
    CDC_ACM_DATA_EPOUT,
    APP_USBD_CDC_COMM_PROTOCOL_AT_V250);

    // USB DEFINES END

    // BLE DEFINES START
    #define APP_BLE_CONN_CFG_TAG 1 /**< A tag identifying the SoftDevice BLE configuration. */

    #define APP_FEATURE_NOT_SUPPORTED BLE_GATT_STATUS_ATTERR_APP_BEGIN + 2 /**< Reply when unsupported features are requested. */

    #define DEVICE_NAME "Nordic_USBD_BLE_UART" /**< Name of device. Will be included in the advertising data. */
    #define NUS_SERVICE_UUID_TYPE BLE_UUID_TYPE_VENDOR_BEGIN /**< UUID type for the Nordic UART Service (vendor specific). */

    #define APP_BLE_OBSERVER_PRIO 3 /**< Application's BLE observer priority. You shouldn't need to modify this value. */

    #define APP_ADV_INTERVAL 64 /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */
    #define APP_ADV_DURATION 18000 /**< The advertising duration (180 seconds) in units of 10 milliseconds. */


    #define MIN_CONN_INTERVAL MSEC_TO_UNITS(20, UNIT_1_25_MS) /**< Minimum acceptable connection interval (20 ms). Connection interval uses 1.25 ms units. */
    #define MAX_CONN_INTERVAL MSEC_TO_UNITS(75, UNIT_1_25_MS) /**< Maximum acceptable connection interval (75 ms). Connection interval uses 1.25 ms units. */
    #define SLAVE_LATENCY 0 /**< Slave latency. */
    #define CONN_SUP_TIMEOUT MSEC_TO_UNITS(4000, UNIT_10_MS) /**< Connection supervisory timeout (4 seconds). Supervision Timeout uses 10 ms units. */
    #define FIRST_CONN_PARAMS_UPDATE_DELAY APP_TIMER_TICKS(5000) /**< Time from initiating an event (connect or start of notification) to the first time sd_ble_gap_conn_param_update is called (5 seconds). */
    #define NEXT_CONN_PARAMS_UPDATE_DELAY APP_TIMER_TICKS(30000) /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
    #define MAX_CONN_PARAMS_UPDATE_COUNT 3 /**< Number of attempts before giving up the connection parameter negotiation. */

    #define DEAD_BEEF 0xDEADBEEF /**< Value used as error code on stack dump. Can be used to identify stack location on stack unwind. */

    #define UART_TX_BUF_SIZE 256 /**< UART TX buffer size. */
    #define UART_RX_BUF_SIZE 256 /**< UART RX buffer size. */

    /*************************Max30105**********************/
    /*MX30105*/

    //Spo2
    #define FreqS 25 //sampling frequency
    #define BUFFER_SIZE (FreqS * 4)
    #define MA4_SIZE 4 // DONOT CHANGE
    #define MX30105_ADDR 0x57
    /*******************************************************/

    BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT); /**< BLE NUS service instance. */
    NRF_BLE_GATT_DEF(m_gatt); /**< GATT module instance. */
    BLE_ADVERTISING_DEF(m_advertising); /**< Advertising module instance. */

    static uint16_t m_conn_handle = BLE_CONN_HANDLE_INVALID; /**< Handle of the current connection. */
    static uint16_t m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3; /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
    static ble_uuid_t m_adv_uuids[] = /**< Universally unique service identifier. */
    {
    {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}
    };
    static char m_nus_data_array[BLE_NUS_MAX_DATA_LEN];

    // BLE DEFINES END

    /***********************Define the varibles of PPG ************************/
    uint32_t example = 0x00;
    int32_t BPM = 0x00;
    int32_t HZ = 0x00;
    int8_t finger = 0;
    int8_t error = 0;
    int16_t example1 = 0;
    uint32_t examplered;
    uint32_t examplegreen;
    uint32_t exampleIR;
    uint32_t validHeartRate = 0 ;
    uint32_t heartRate = 0 ;
    uint32_t validSPO2 = 0;
    uint32_t spo2 = 0;
    /******************************End of definition of varibles PPG *****************/

    /* Timer Stuff */

    const nrf_drv_rtc_t rtc = NRF_DRV_RTC_INSTANCE(0);

    static void rtc_handler(nrf_drv_rtc_int_type_t int_type)
    {
    if (int_type == NRF_DRV_RTC_INT_COMPARE0)
    {
    NRF_LOG_INFO("Compare event ");
    }
    else if (int_type == NRF_DRV_RTC_INT_TICK)
    {
    NRF_LOG_INFO(" Tick Event ");
    }
    }

    /** @brief Function starting the internal LFCLK XTAL oscillator.
    */
    /*static void lfclk_config(void)
    { ret_code_t err_code = nrf_drv_clock_init();
    APP_ERROR_CHECK(err_code);

    nrf_drv_clock_lfclk_request(NULL);
    NRF_LOG_INFO(" Low Frequency Configuration done ");
    }

    */
    /*static void rtc_config(void)
    {
    uint32_t err_code;

    //Initialize RTC instance
    nrf_drv_rtc_config_t config = NRF_DRV_RTC_DEFAULT_CONFIG;
    config.prescaler = 327;
    err_code = nrf_drv_rtc_init(&rtc, &config, rtc_handler);
    APP_ERROR_CHECK(err_code);
    nrf_drv_rtc_enable(&rtc);
    NRF_LOG_INFO("RTC Configuration done");
    }
    */
    static int32_t an_x[ BUFFER_SIZE]; //ir
    static int32_t an_y[ BUFFER_SIZE]; //red
    const uint8_t uch_spo2_table[184]={ 95, 95, 95, 96, 96, 96, 97, 97, 97, 97, 97, 98, 98, 98, 98, 98, 99, 99, 99, 99,
    99, 99, 99, 99, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100,
    100, 100, 100, 100, 99, 99, 99, 99, 99, 99, 99, 99, 98, 98, 98, 98, 98, 98, 97, 97,
    97, 97, 96, 96, 96, 96, 95, 95, 95, 94, 94, 94, 93, 93, 93, 92, 92, 92, 91, 91,
    90, 90, 89, 89, 89, 88, 88, 87, 87, 86, 86, 85, 85, 84, 84, 83, 82, 82, 81, 81,
    80, 80, 79, 78, 78, 77, 76, 76, 75, 74, 74, 73, 72, 72, 71, 70, 69, 69, 68, 67,
    66, 66, 65, 64, 63, 62, 62, 61, 60, 59, 58, 57, 56, 56, 55, 54, 53, 52, 51, 50,
    49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 31, 30, 29,
    28, 27, 26, 25, 23, 22, 21, 20, 19, 17, 16, 15, 14, 12, 11, 10, 9, 7, 6, 5,
    3, 2, 1 } ;
    /* TWI instance. */
    static const nrf_drv_twi_t m_twi = NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID);


    /**
    * @brief TWI initialization.
    */
    void twi_init (void)
    {
    ret_code_t err_code;

    const nrf_drv_twi_config_t twi_config = {
    .scl = ARDUINO_SCL_PIN,
    .sda = ARDUINO_SDA_PIN,
    .frequency = NRF_DRV_TWI_FREQ_100K,
    .interrupt_priority = APP_IRQ_PRIORITY_HIGH,
    .clear_bus_init = true
    };

    err_code = nrf_drv_twi_init(&m_twi, &twi_config, NULL, NULL);
    APP_ERROR_CHECK(err_code);

    nrf_drv_twi_enable(&m_twi);
    }


    /**
    * @brief Function for main application entry.
    */


    uint32_t redBuffer[100];
    uint32_t irBuffer[100];
    uint32_t greenBuffer[100];


    /**
    * @brief Function for assert macro callback.
    *
    * @details This function will be called in case of an assert in the SoftDevice.
    *
    * @warning This handler is an example only and does not fit a final product. You need to analyze
    * how your product is supposed to react in case of an assert.
    * @warning On assert from the SoftDevice, the system can only recover on reset.
    *
    * @param[in] line_num Line number of the failing ASSERT call.
    * @param[in] p_file_name File name of the failing ASSERT call.
    */
    void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
    {
    app_error_handler(DEAD_BEEF, line_num, p_file_name);
    }

    /** @brief Function for initializing the timer module. */
    static void timers_init(void)
    {
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
    err_code = app_timer_create(&m_blink_ble, APP_TIMER_MODE_REPEATED, blink_handler);
    APP_ERROR_CHECK(err_code);
    err_code = app_timer_create(&m_blink_cdc, APP_TIMER_MODE_REPEATED, blink_handler);
    APP_ERROR_CHECK(err_code);
    }

    /**
    * @brief Function for the GAP initialization.
    *
    * @details This function sets up all the necessary GAP (Generic Access Profile) parameters of
    * the device. It also sets the permissions and appearance.
    */
    static void gap_params_init(void)
    {
    uint32_t err_code;
    ble_gap_conn_params_t gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    err_code = sd_ble_gap_device_name_set(&sec_mode,
    (const uint8_t *) DEVICE_NAME,
    strlen(DEVICE_NAME));
    APP_ERROR_CHECK(err_code);

    memset(&gap_conn_params, 0, sizeof(gap_conn_params));

    gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
    gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
    gap_conn_params.slave_latency = SLAVE_LATENCY;
    gap_conn_params.conn_sup_timeout = CONN_SUP_TIMEOUT;

    err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
    APP_ERROR_CHECK(err_code);
    }


    /**
    * @brief Function for handling the data from the Nordic UART Service.
    *
    * @details This function processes the data received from the Nordic UART BLE Service and sends
    * it to the USBD CDC ACM module.
    *
    * @param[in] p_evt Nordic UART Service event.
    */
    static void nus_data_handler(ble_nus_evt_t * p_evt)
    {

    if (p_evt->type == BLE_NUS_EVT_RX_DATA)
    {
    bsp_board_led_invert(LED_BLE_NUS_RX);
    NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on CDC ACM.");
    NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
    memcpy(m_nus_data_array, p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);

    // Add endline characters
    uint16_t length = p_evt->params.rx_data.length;
    if (length + sizeof(ENDLINE_STRING) < BLE_NUS_MAX_DATA_LEN)
    {
    memcpy(m_nus_data_array + length, ENDLINE_STRING, sizeof(ENDLINE_STRING));
    length += sizeof(ENDLINE_STRING);
    }

    // Send data through CDC ACM
    ret_code_t ret = app_usbd_cdc_acm_write(&m_app_cdc_acm,
    m_nus_data_array,
    length);
    if(ret != NRF_SUCCESS)
    {
    NRF_LOG_INFO("CDC ACM unavailable, data received: %s", m_nus_data_array);
    }
    }

    }


    /** @brief Function for initializing services that will be used by the application. */
    static void services_init(void)
    {
    uint32_t err_code;
    ble_nus_init_t nus_init;

    memset(&nus_init, 0, sizeof(nus_init));

    nus_init.data_handler = nus_data_handler;

    err_code = ble_nus_init(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);
    }

    /**
    * @brief Function for handling errors from the Connection Parameters module.
    *
    * @param[in] nrf_error Error code containing information about what went wrong.
    */
    static void conn_params_error_handler(uint32_t nrf_error)
    {
    APP_ERROR_HANDLER(nrf_error);
    }


    /** @brief Function for initializing the Connection Parameters module. */
    static void conn_params_init(void)
    {
    uint32_t err_code;
    ble_conn_params_init_t cp_init;

    memset(&cp_init, 0, sizeof(cp_init));

    cp_init.p_conn_params = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle = BLE_GATT_HANDLE_INVALID;
    cp_init.disconnect_on_fail = true;
    cp_init.evt_handler = NULL;
    cp_init.error_handler = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
    }


    /**
    * @brief Function for putting the chip into sleep mode.
    *
    * @note This function does not return.
    */
    static void sleep_mode_enter(void)
    {
    uint32_t err_code = bsp_indication_set(BSP_INDICATE_IDLE);
    APP_ERROR_CHECK(err_code);

    // Prepare wakeup buttons.
    err_code = bsp_btn_ble_sleep_mode_prepare();
    APP_ERROR_CHECK(err_code);

    // Go to system-off mode (this function will not return; wakeup will cause a reset).
    err_code = sd_power_system_off();
    APP_ERROR_CHECK(err_code);
    }


    /** @brief Function for starting advertising. */
    static void advertising_start(void)
    {
    uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(err_code);
    }

    /**
    * @brief Function for handling advertising events.
    *
    * @details This function is called for advertising events which are passed to the application.
    *
    * @param[in] ble_adv_evt Advertising event.
    */
    static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
    {
    uint32_t err_code;

    switch (ble_adv_evt)
    {
    case BLE_ADV_EVT_FAST:
    err_code = app_timer_start(m_blink_ble,
    APP_TIMER_TICKS(LED_BLINK_INTERVAL),
    (void *) LED_BLE_NUS_CONN);
    APP_ERROR_CHECK(err_code);
    break;
    case BLE_ADV_EVT_IDLE:
    NRF_LOG_INFO("Advertising timeout, restarting.")
    advertising_start();
    break;
    default:
    break;
    }
    }


    /**
    * @brief Function for handling BLE events.
    *
    * @param[in] p_ble_evt Bluetooth stack event.
    * @param[in] p_context Unused.
    */
    static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
    {
    uint32_t err_code;

    switch (p_ble_evt->header.evt_id)
    {
    case BLE_GAP_EVT_CONNECTED:
    NRF_LOG_INFO("BLE NUS connected");
    err_code = app_timer_stop(m_blink_ble);
    APP_ERROR_CHECK(err_code);
    bsp_board_led_on(LED_BLE_NUS_CONN);
    m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
    break;

    case BLE_GAP_EVT_DISCONNECTED:
    NRF_LOG_INFO("BLE NUS disconnected");
    // LED indication will be changed when advertising starts.
    m_conn_handle = BLE_CONN_HANDLE_INVALID;
    break;

    case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
    {
    NRF_LOG_DEBUG("PHY update request.");
    ble_gap_phys_t const phys =
    {
    .rx_phys = BLE_GAP_PHY_AUTO,
    .tx_phys = BLE_GAP_PHY_AUTO,
    };
    err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
    APP_ERROR_CHECK(err_code);
    } break;

    case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
    // Pairing not supported.
    err_code = sd_ble_gap_sec_params_reply(m_conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
    APP_ERROR_CHECK(err_code);
    break;

    case BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST:
    {
    ble_gap_data_length_params_t dl_params;

    // Clearing the struct will effectively set members to @ref BLE_GAP_DATA_LENGTH_AUTO.
    memset(&dl_params, 0, sizeof(ble_gap_data_length_params_t));
    err_code = sd_ble_gap_data_length_update(p_ble_evt->evt.gap_evt.conn_handle, &dl_params, NULL);
    APP_ERROR_CHECK(err_code);
    } break;

    case BLE_GATTS_EVT_SYS_ATTR_MISSING:
    // No system attributes have been stored.
    err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
    APP_ERROR_CHECK(err_code);
    break;

    case BLE_GATTC_EVT_TIMEOUT:
    // Disconnect on GATT Client timeout event.
    err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
    BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    APP_ERROR_CHECK(err_code);
    break;

    case BLE_GATTS_EVT_TIMEOUT:
    // Disconnect on GATT Server timeout event.
    err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
    BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    APP_ERROR_CHECK(err_code);
    break;

    case BLE_EVT_USER_MEM_REQUEST:
    err_code = sd_ble_user_mem_reply(p_ble_evt->evt.gattc_evt.conn_handle, NULL);
    APP_ERROR_CHECK(err_code);
    break;

    case BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST:
    {
    ble_gatts_evt_rw_authorize_request_t req;
    ble_gatts_rw_authorize_reply_params_t auth_reply;

    req = p_ble_evt->evt.gatts_evt.params.authorize_request;

    if (req.type != BLE_GATTS_AUTHORIZE_TYPE_INVALID)
    {
    if ((req.request.write.op == BLE_GATTS_OP_PREP_WRITE_REQ) ||
    (req.request.write.op == BLE_GATTS_OP_EXEC_WRITE_REQ_NOW) ||
    (req.request.write.op == BLE_GATTS_OP_EXEC_WRITE_REQ_CANCEL))
    {
    if (req.type == BLE_GATTS_AUTHORIZE_TYPE_WRITE)
    {
    auth_reply.type = BLE_GATTS_AUTHORIZE_TYPE_WRITE;
    }
    else
    {
    auth_reply.type = BLE_GATTS_AUTHORIZE_TYPE_READ;
    }
    auth_reply.params.write.gatt_status = APP_FEATURE_NOT_SUPPORTED;
    err_code = sd_ble_gatts_rw_authorize_reply(p_ble_evt->evt.gatts_evt.conn_handle,
    &auth_reply);
    APP_ERROR_CHECK(err_code);
    }
    }
    } break; // BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST

    default:
    // No implementation needed.
    break;
    }
    }


    /**
    * @brief Function for the SoftDevice initialization.
    *
    * @details This function initializes the SoftDevice and the BLE event interrupt.
    */
    static void ble_stack_init(void)
    {
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    }


    /** @brief Function for handling events from the GATT library. */
    void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
    {
    if ((m_conn_handle == p_evt->conn_handle) && (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
    {
    m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
    NRF_LOG_INFO("Data len is set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
    NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
    p_gatt->att_mtu_desired_central,
    p_gatt->att_mtu_desired_periph);
    }


    /** @brief Function for initializing the GATT library. */
    void gatt_init(void)
    {
    ret_code_t err_code;

    err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, 64);
    APP_ERROR_CHECK(err_code);
    }


    /**
    * @brief Function for handling events from the BSP module.
    *
    * @param[in] event Event generated by button press.
    */
    void bsp_event_handler(bsp_event_t event)
    {
    uint32_t err_code;
    switch (event)
    {
    case BSP_EVENT_SLEEP:
    sleep_mode_enter();
    break;

    case BSP_EVENT_DISCONNECT:
    err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
    if (err_code != NRF_ERROR_INVALID_STATE)
    {
    APP_ERROR_CHECK(err_code);
    }
    break;

    case BSP_EVENT_WHITELIST_OFF:
    if (m_conn_handle == BLE_CONN_HANDLE_INVALID)
    {
    err_code = ble_advertising_restart_without_whitelist(&m_advertising);
    if (err_code != NRF_ERROR_INVALID_STATE)
    {
    APP_ERROR_CHECK(err_code);
    }
    }
    break;

    default:
    break;
    }
    }

    /** @brief Function for initializing the Advertising functionality. */
    static void advertising_init(void)
    {
    uint32_t err_code;
    ble_advertising_init_t init;

    memset(&init, 0, sizeof(init));

    init.advdata.name_type = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance = false;
    init.advdata.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;

    init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.srdata.uuids_complete.p_uuids = m_adv_uuids;

    init.config.ble_adv_fast_enabled = true;
    init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
    init.config.ble_adv_fast_timeout = APP_ADV_DURATION;

    init.evt_handler = on_adv_evt;

    err_code = ble_advertising_init(&m_advertising, &init);
    APP_ERROR_CHECK(err_code);

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
    }


    /** @brief Function for initializing buttons and LEDs. */
    static void buttons_leds_init(void)
    {
    uint32_t err_code = bsp_init(BSP_INIT_LEDS, bsp_event_handler);
    APP_ERROR_CHECK(err_code);
    }


    /** @brief Function for initializing the nrf_log module. */
    static void log_init(void)
    {
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
    }


    /** @brief Function for placing the application in low power state while waiting for events. */
    static void power_manage(void)
    {
    uint32_t err_code = sd_app_evt_wait();
    APP_ERROR_CHECK(err_code);
    }


    /**
    * @brief Function for handling the idle state (main loop).
    *
    * @details If there is no pending log operation, then sleep until next the next event occurs.
    */
    static void idle_state_handle(void)
    {
    UNUSED_RETURN_VALUE(NRF_LOG_PROCESS());
    power_manage();
    }


    // USB CODE START
    static bool m_usb_connected = false;


    /** @brief User event handler @ref app_usbd_cdc_acm_user_ev_handler_t */
    static void cdc_acm_user_ev_handler(app_usbd_class_inst_t const * p_inst,
    app_usbd_cdc_acm_user_event_t event)
    {
    app_usbd_cdc_acm_t const * p_cdc_acm = app_usbd_cdc_acm_class_get(p_inst);

    switch (event)
    {
    case APP_USBD_CDC_ACM_USER_EVT_PORT_OPEN:
    {
    /*Set up the first transfer*/
    ret_code_t ret = app_usbd_cdc_acm_read(&m_app_cdc_acm,
    m_cdc_data_array,
    1);
    UNUSED_VARIABLE(ret);
    ret = app_timer_stop(m_blink_cdc);
    APP_ERROR_CHECK(ret);
    bsp_board_led_on(LED_CDC_ACM_CONN);
    NRF_LOG_INFO("CDC ACM port opened");
    break;
    }

    case APP_USBD_CDC_ACM_USER_EVT_PORT_CLOSE:
    NRF_LOG_INFO("CDC ACM port closed");
    if (m_usb_connected)
    {
    ret_code_t ret = app_timer_start(m_blink_cdc,
    APP_TIMER_TICKS(LED_BLINK_INTERVAL),
    (void *) LED_CDC_ACM_CONN);
    APP_ERROR_CHECK(ret);
    }
    break;

    case APP_USBD_CDC_ACM_USER_EVT_TX_DONE:
    break;

    case APP_USBD_CDC_ACM_USER_EVT_RX_DONE:
    {
    ret_code_t ret;
    static uint8_t index = 0;
    index++;

    do
    {
    if ((m_cdc_data_array[index - 1] == '\n') ||
    (m_cdc_data_array[index - 1] == '\r') ||
    (index >= (m_ble_nus_max_data_len)))
    {
    if (index > 1)
    {
    bsp_board_led_invert(LED_CDC_ACM_RX);
    NRF_LOG_DEBUG("Ready to send data over BLE NUS");
    NRF_LOG_HEXDUMP_DEBUG(m_cdc_data_array, index);
    NRF_LOG_INFO ( "%s" , m_cdc_data_array);
    // readuart(m_cdc_data_array,index)


    // NRF_LOG_INFO(m_cdc_data_array);

    do
    {
    uint16_t length = (uint16_t)index;
    if (length + sizeof(ENDLINE_STRING) < BLE_NUS_MAX_DATA_LEN)
    {
    memcpy(m_cdc_data_array + length, ENDLINE_STRING, sizeof(ENDLINE_STRING));
    length += sizeof(ENDLINE_STRING);
    }
    ret_code_t ret = app_usbd_cdc_acm_write(&m_app_cdc_acm,
    m_cdc_data_array,
    index);
    ret = ble_nus_data_send(&m_nus,
    (uint8_t *) m_cdc_data_array,
    &length,
    m_conn_handle);

    if (ret == NRF_ERROR_NOT_FOUND)
    {
    NRF_LOG_INFO("BLE NUS unavailable, data received: %s", m_cdc_data_array);
    break;
    }

    if (ret == NRF_ERROR_RESOURCES)
    {
    NRF_LOG_ERROR("BLE NUS Too many notifications queued.");
    break;
    }

    if ((ret != NRF_ERROR_INVALID_STATE) && (ret != NRF_ERROR_BUSY))
    {
    APP_ERROR_CHECK(ret);
    }
    }
    while (ret == NRF_ERROR_BUSY);
    }

    index = 0;
    }

    /*Get amount of data transferred*/
    size_t size = app_usbd_cdc_acm_rx_size(p_cdc_acm);
    NRF_LOG_DEBUG("RX: size: %lu char: %c", size, m_cdc_data_array[index - 1]);

    /* Fetch data until internal buffer is empty */
    ret = app_usbd_cdc_acm_read(&m_app_cdc_acm,
    &m_cdc_data_array[index],
    1);
    if (ret == NRF_SUCCESS)
    {
    index++;
    }
    }
    while (ret == NRF_SUCCESS);

    break;
    }
    default:
    break;
    }
    }

    static void usbd_user_ev_handler(app_usbd_event_type_t event)
    {
    switch (event)
    {
    case APP_USBD_EVT_DRV_SUSPEND:
    break;

    case APP_USBD_EVT_DRV_RESUME:
    break;

    case APP_USBD_EVT_STARTED:
    break;

    case APP_USBD_EVT_STOPPED:
    app_usbd_disable();
    break;

    case APP_USBD_EVT_POWER_DETECTED:
    NRF_LOG_INFO("USB power detected");

    if (!nrf_drv_usbd_is_enabled())
    {
    app_usbd_enable();
    }
    break;

    case APP_USBD_EVT_POWER_REMOVED:
    {
    NRF_LOG_INFO("USB power removed");
    ret_code_t err_code = app_timer_stop(m_blink_cdc);
    APP_ERROR_CHECK(err_code);
    bsp_board_led_off(LED_CDC_ACM_CONN);
    m_usb_connected = false;
    app_usbd_stop();
    }
    break;

    case APP_USBD_EVT_POWER_READY:
    {
    NRF_LOG_INFO("USB ready");
    ret_code_t err_code = app_timer_start(m_blink_cdc,
    APP_TIMER_TICKS(LED_BLINK_INTERVAL),
    (void *) LED_CDC_ACM_CONN);
    APP_ERROR_CHECK(err_code);
    m_usb_connected = true;
    app_usbd_start();
    }
    break;

    default:
    break;
    }
    }

    // USB CODE END
    void sendcom(char c[]){
    uint8_t length;
    length =strlen(c);
    ret_code_t ret = app_usbd_cdc_acm_write(&m_app_cdc_acm,
    c,
    length);
    if(ret != NRF_SUCCESS)
    {
    NRF_LOG_INFO("Data not sent,Please Open Com to send data : %s", c);
    }
    }

    /** @brief Application main function. */
    int main(void)

    {
    /*******************************For PPG ********************/
    uint32_t Max_ADC;
    uint32_t Max_ADC2;
    uint32_t Max_ADC3;
    uint8_t address;
    ret_code_t err_code;
    uint8_t sample_data;
    uint8_t FIFO_Configuration = 0;
    uint8_t Mode_Configuration = 0;
    uint8_t SpO2_Configuration = 0;
    uint8_t RESERVED;
    uint8_t Multi_LED_Mode_Control1= 0;
    uint8_t Multi_LED_Mode_Control2= 0;
    uint8_t FIFO_Write_Pointer= 0;
    uint8_t Over_Flow_Counter= 0;
    uint8_t FIFO_Read_Pointer=0;
    uint8_t FIFO_Data_Register[288];
    uint8_t FIFO_Configuration1 = 0;
    uint8_t Mode_Configuration1 = 0;
    uint8_t SpO2_Configuration1 = 0;
    uint8_t RESERVED1;
    uint8_t Multi_LED_Mode_Control11= 0;
    uint8_t Multi_LED_Mode_Control21= 0;
    uint8_t FIFO_Write_Pointer1= 0;
    uint8_t Over_Flow_Counter1= 0;
    uint8_t FIFO_Read_Pointer1=0;
    uint8_t FIFO_Data_Register1[288];

    //configuration :


    const uint8_t FIFO_Write_PointerADD = 0x04;
    const uint8_t Over_Flow_CounterADD = 0x05;
    const uint8_t FIFO_Read_PointerADD = 0x06;
    const uint8_t FIFO_Data_RegisterADD = 0x07;
    const uint8_t FIFO_ConfigurationADD = 0x08;
    const uint8_t Mode_ConfigurationADD = 0x09;
    const uint8_t SpO2_ConfigurationADD = 0x0A;
    const uint8_t RESERVEDADD = 0x0B;
    const uint8_t LED_PulseAmplitude1ADD = 0x0C;
    const uint8_t LED_PulseAmplitude2ADD = 0x0D;
    const uint8_t LED_PulseAmplitude3ADD = 0x0E;
    const uint8_t LED_PulseAmplitude4ADD = 0x0F;
    const uint8_t Multi_LED_Mode_Control1ADD = 0x11;
    const uint8_t Multi_LED_Mode_Control2ADD = 0x12;
    const uint8_t Temp_Integer = 0x1F;
    const uint8_t Temp_Fraction = 0x20; //only last 4 bits
    const uint8_t Die_Temperature_Config = 0x21; //only one bit


    //masks//
    const uint8_t SMP_AVE_MASK =0x1F;
    const uint8_t FIFO_ROLLOVER_EN_MASK =0xEF;
    const uint8_t FIFO_A_FULL_MASK =0xF0;
    const uint8_t SHDN_MASK =0x7F;
    const uint8_t RESET_MASK =0xBF;
    const uint8_t MODE_MASK =0xF8;
    const uint8_t SPO2_ADC_RGE_MASK =0x9F;
    const uint8_t SPO2_SR_MASK =0xE3;
    const uint8_t LED_PW_MASK =0xFC;
    const uint8_t SLOT1_MASK =0xF8;
    const uint8_t SLOT2_MASK =0x8F;
    const uint8_t SLOT3_MASK =0xF8;
    const uint8_t SLOT4_MASK =0x8F;


    // test variables
    uint8_t masked = 0x00; // too
    uint8_t notshifted= 0x01;
    uint8_t shifted = 0x00;
    uint8_t ReadySamples = 0x00;
    //Configuration of MAX30105 Heart Rate ------- SPO2
    uint8_t SMP_AVE =0x00;
    uint8_t FIFO_ROLLOVER_EN =0x00;
    uint8_t FIFO_A_FULL =0x00 ;
    uint8_t SHDN =0x00 ;
    uint8_t RESET =0x00 ;
    uint8_t MODE =0x00 ;
    uint8_t SPO2_ADC_RGE =0x00 ;
    uint8_t SPO2_SR =0x00 ;
    uint8_t LED_PulseAmplitude1 = 0x00;
    uint8_t LED_PulseAmplitude2 = 0x00;
    uint8_t LED_PulseAmplitude3 = 0x00;
    uint8_t LED_PulseAmplitude4 = 0x00;
    uint8_t LED_PW =0x00;
    uint8_t SLOT1 =0x00 ;
    uint8_t SLOT2 =0x00 ;
    uint8_t SLOT3 =0x00 ;
    uint8_t SLOT4 =0x00 ;
    uint8_t lednumber = 0x00;

    /***********************************************************/
    /***********************************************************/
    /************************************************************/

    ret_code_t ret;
    static const app_usbd_config_t usbd_config = {
    .ev_state_proc = usbd_user_ev_handler
    };
    // Initialize.
    bool detected_device = false;
    log_init();
    // APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
    //NRF_LOG_DEFAULT_BACKENDS_INIT();
    twi_init();



    for (address = 1; address <= TWI_ADDRESSES; address++)
    {
    err_code = nrf_drv_twi_rx(&m_twi, address, &sample_data, sizeof(sample_data));
    if (err_code == NRF_SUCCESS)
    {
    detected_device = true;
    NRF_LOG_INFO("TWI device detected at address 0x%x.", address);
    }
    NRF_LOG_FLUSH();
    nrf_delay_ms(10);
    }

    if (!detected_device)
    {
    NRF_LOG_INFO("hi there");

    NRF_LOG_INFO("No device was found.");
    NRF_LOG_FLUSH();
    }


    timers_init();

    buttons_leds_init();

    app_usbd_serial_num_generate();

    ret = nrf_drv_clock_init();
    APP_ERROR_CHECK(ret);

    NRF_LOG_INFO("USBD BLE UART example started.");

    ret = app_usbd_init(&usbd_config);
    APP_ERROR_CHECK(ret);

    app_usbd_class_inst_t const * class_cdc_acm = app_usbd_cdc_acm_class_inst_get(&m_app_cdc_acm);
    ret = app_usbd_class_append(class_cdc_acm);
    APP_ERROR_CHECK(ret);

    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();

    // Start execution.

    /*********************************************For PPG**************************************/
    /******************************************************************************************/
    /*******************************************************************************************/
    /*--------------------------------------READING COMMAND-------------------------------*/
    /*--------------------------------------READING COMMAND-------------------------------*/
    /*--------------------------------------READING COMMAND-------------------------------*/


    uint8_t Read(uint8_t address)
    {
    uint8_t temp;
    bsp_board_led_invert(4);
    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&address, 1, false);
    nrf_delay_ms(10);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &temp,1);
    nrf_delay_ms(10);
    if (err_code == NRF_SUCCESS)
    {
    // NRF_LOG_RAW_INFO(" 0x%x at 0x%x ", temp ,address );
    //NRF_LOG_INFO(" ");
    NRF_LOG_FLUSH();
    return temp;
    bsp_board_led_invert(4);
    }
    }
    /*--------------------------------------SENDING COMMAND-------------------------------*/
    /*--------------------------------------SENDING COMMAND-------------------------------*/
    /*--------------------------------------SENDING COMMAND-------------------------------*/

    void Send(uint8_t address, uint8_t command)
    {
    uint8_t fifoconfig_Reg[2]={address,command} ;
    bsp_board_led_invert(2);
    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&fifoconfig_Reg, sizeof(fifoconfig_Reg), false);
    nrf_delay_ms(10);
    if (err_code == NRF_SUCCESS)
    {
    // NRF_LOG_INFO(" Sent : 0x%x to 0x%x", command,address);
    //NRF_LOG_FLUSH();
    bsp_board_led_invert(2);
    }
    }

    void Softreset()
    {
    // NRF_LOG_RAW_INFO("Reading Mode_Configuration for Reset : ");
    Mode_Configuration = Read(Mode_ConfigurationADD);
    Mode_Configuration = (Mode_Configuration & RESET_MASK) | (0x01 << 6) ;
    Send(Mode_ConfigurationADD,Mode_Configuration);
    nrf_delay_ms(250);
    // NRF_LOG_INFO(" Soft Reset Done ");
    }
    void Readall(){

    // NRF_LOG_RAW_INFO("FIFO_Configuration : ");
    FIFO_Configuration = Read(FIFO_ConfigurationADD);

    //NRF_LOG_RAW_INFO("Mode_Configuration : ");
    Mode_Configuration = Read(Mode_ConfigurationADD);

    //NRF_LOG_RAW_INFO("SpO2_Configuration : ");
    SpO2_Configuration = Read(SpO2_ConfigurationADD);

    // NRF_LOG_RAW_INFO("Multi_LED_Mode_Con1 : ");
    Multi_LED_Mode_Control1 = Read(Multi_LED_Mode_Control1ADD);

    //NRF_LOG_RAW_INFO("Multi_LED_Mode_Con2 : ");
    Multi_LED_Mode_Control2 = Read(Multi_LED_Mode_Control2ADD);

    //NRF_LOG_RAW_INFO("LED_PulseAmplitude1 : ");
    LED_PulseAmplitude1 = Read(LED_PulseAmplitude1ADD);

    //NRF_LOG_RAW_INFO("LED_PulseAmplitude2 : ");
    LED_PulseAmplitude2 = Read(LED_PulseAmplitude2ADD);

    //NRF_LOG_RAW_INFO("LED_PulseAmplitude3 : ");
    LED_PulseAmplitude3 = Read(LED_PulseAmplitude3ADD);

    //NRF_LOG_RAW_INFO("LED_PulseAmplitude4 : ");
    LED_PulseAmplitude4 = Read(LED_PulseAmplitude4ADD);
    }

    void ConfigureSampleAverage(uint8_t SampleAverage)
    {
    SampleAverage = SampleAverage << 5;
    //NRF_LOG_RAW_INFO("Reading FIFO_CONFIGURATION for SampleAverage : ");
    FIFO_Configuration = Read(FIFO_ConfigurationADD);
    FIFO_Configuration = (FIFO_Configuration & SMP_AVE_MASK) | SampleAverage ;
    Send(FIFO_ConfigurationADD,FIFO_Configuration);
    FIFO_Configuration = Read(FIFO_ConfigurationADD);
    }

    void Enablefiforollover()
    {
    //NRF_LOG_RAW_INFO("Reading FIFO_CONFIGURATION for Enabling Rollover : ");
    FIFO_Configuration = Read(FIFO_ConfigurationADD);
    FIFO_Configuration = (FIFO_Configuration & FIFO_ROLLOVER_EN_MASK) | ( 0x01 << 4 ) ;
    Send(FIFO_ConfigurationADD,FIFO_Configuration);
    // NRF_LOG_RAW_INFO("comfirm FIFO_CONFIGURATION for Enabling Rollover : ");
    FIFO_Configuration = Read(FIFO_ConfigurationADD);
    }

    void Disablefiforollover()
    {
    NRF_LOG_RAW_INFO("Reading FIFO_CONFIGURATION for Enabling Rollover : ");
    FIFO_Configuration = Read(FIFO_ConfigurationADD);
    FIFO_Configuration = (FIFO_Configuration & FIFO_ROLLOVER_EN_MASK) | ( 0x00 << 4 ) ;
    Send(FIFO_ConfigurationADD,FIFO_Configuration);
    NRF_LOG_RAW_INFO("Comfirm FIFO_CONFIGURATION for Enabling Rollover : ");
    FIFO_Configuration = Read(FIFO_ConfigurationADD);
    }

    void Setmode(uint8_t mode)
    {
    if (mode == 0x02){
    lednumber =1;
    }
    if (mode == 0x03){
    lednumber =2;
    }
    if (mode == 0x07){
    lednumber =3;
    }

    // NRF_LOG_RAW_INFO("Reading Mode_CONFIGURATION for Enabling Rollover : ");
    Mode_Configuration = Read(Mode_ConfigurationADD);
    Mode_Configuration = (Mode_Configuration & MODE_MASK) | mode ;
    Send(Mode_ConfigurationADD,Mode_Configuration);
    //NRF_LOG_RAW_INFO("Comfirm Mode_CONFIGURATION for Enabling Rollover : ");
    Mode_Configuration = Read(Mode_ConfigurationADD);
    }
    void Ledpulsewidth(uint8_t LED_PW){
    //NRF_LOG_RAW_INFO("Reading Spo2_CONFIGURATION for Led pulse width : ");
    SpO2_Configuration = Read(SpO2_ConfigurationADD);
    SpO2_Configuration = (SpO2_Configuration & LED_PW_MASK) | LED_PW ;
    Send(SpO2_ConfigurationADD,SpO2_Configuration);
    //NRF_LOG_RAW_INFO("comfirm Spo2_CONFIGURATION for Led pulse width : ");
    SpO2_Configuration = Read(SpO2_ConfigurationADD);
    }
    void Spo2samplerate(uint8_t SPO2_SR)
    {
    SPO2_SR = SPO2_SR << 2;
    //NRF_LOG_RAW_INFO("Reading Spo2_CONFIGURATION for Spo2samplerate : ");
    SpO2_Configuration = Read(SpO2_ConfigurationADD);
    SpO2_Configuration = (SpO2_Configuration & SPO2_SR_MASK) | SPO2_SR ;
    Send(SpO2_ConfigurationADD,SpO2_Configuration);
    //NRF_LOG_RAW_INFO("comfirm Spo2_CONFIGURATION for Led pulse width : ");
    SpO2_Configuration = Read(SpO2_ConfigurationADD);
    }
    void Spo2adcrange(uint8_t SPO2_ADC_RGE ){
    SPO2_ADC_RGE = SPO2_ADC_RGE << 5;
    // NRF_LOG_RAW_INFO("Reading Spo2_CONFIGURATION for Spo2adcrange : ");
    SpO2_Configuration = Read(SpO2_ConfigurationADD);
    SpO2_Configuration = (SpO2_Configuration & SPO2_ADC_RGE_MASK) | SPO2_ADC_RGE ;
    Send(SpO2_ConfigurationADD,SpO2_Configuration);
    //NRF_LOG_RAW_INFO("comfirm Spo2_CONFIGURATION for Spo2adcrange : ");
    SpO2_Configuration = Read(SpO2_ConfigurationADD);
    }

    void Led1pulseamplitude(uint8_t amplitude){
    Send( LED_PulseAmplitude1ADD,amplitude);
    // NRF_LOG_RAW_INFO("Led1 Pulse Amplitude : ");
    amplitude = Read(LED_PulseAmplitude1ADD);
    }
    void Led2pulseamplitude(uint8_t amplitude){
    Send( LED_PulseAmplitude2ADD,amplitude);
    //NRF_LOG_RAW_INFO("Led2 Pulse Amplitude : ");
    amplitude = Read(LED_PulseAmplitude2ADD);
    }
    void Led3pulseamplitude(uint8_t amplitude){
    Send( LED_PulseAmplitude3ADD,amplitude);
    //NRF_LOG_RAW_INFO("Led3 Pulse Amplitude : ");
    amplitude = Read(LED_PulseAmplitude3ADD);
    }
    void Led4pulseamplitude(uint8_t amplitude){
    Send( LED_PulseAmplitude4ADD,amplitude);
    //NRF_LOG_RAW_INFO("Led4 Pulse Amplitude : ");
    amplitude = Read(LED_PulseAmplitude4ADD);

    }
    void slot1(uint8_t SLOT1) {
    //NRF_LOG_RAW_INFO("Reading Multi_LED_Mode_Control1 for SLOT1 : ");
    Multi_LED_Mode_Control1 = Read(Multi_LED_Mode_Control1ADD) ;
    Multi_LED_Mode_Control1 = (Multi_LED_Mode_Control1 & SLOT1_MASK) | SLOT1 ;

    Send( Multi_LED_Mode_Control1ADD,Multi_LED_Mode_Control1);
    //NRF_LOG_RAW_INFO("Comfirm Multi_LED_Mode_Control1 for SLOT1 : ");
    Multi_LED_Mode_Control1 = Read(Multi_LED_Mode_Control1ADD) ;

    }
    void slot2(uint8_t SLOT2) {
    SLOT2 =SLOT2 << 4;
    //NRF_LOG_RAW_INFO("Reading Multi_LED_Mode_Control1 for SLOT2 : ");
    Multi_LED_Mode_Control1 = Read(Multi_LED_Mode_Control1ADD) ;
    Multi_LED_Mode_Control1 = (Multi_LED_Mode_Control1 & SLOT2_MASK) | SLOT2 ;

    Send( Multi_LED_Mode_Control1ADD,Multi_LED_Mode_Control1);
    //NRF_LOG_RAW_INFO("Comfirm Multi_LED_Mode_Control1 for SLOT2 : ");
    Multi_LED_Mode_Control1 = Read(Multi_LED_Mode_Control1ADD) ;


    }
    void slot3(uint8_t SLOT3) {
    //NRF_LOG_RAW_INFO("Reading Multi_LED_Mode_Control1 for SLOT1 : ");
    Multi_LED_Mode_Control2 = Read(Multi_LED_Mode_Control2ADD) ;
    Multi_LED_Mode_Control2 = (Multi_LED_Mode_Control2 & SLOT3_MASK) | SLOT3 ;

    Send( Multi_LED_Mode_Control2ADD,Multi_LED_Mode_Control2);
    //NRF_LOG_RAW_INFO("Comfirm Multi_LED_Mode_Control1 for SLOT1 : ");
    Multi_LED_Mode_Control2 = Read(Multi_LED_Mode_Control2ADD) ;

    }
    void slot4(uint8_t SLOT4) {
    SLOT4 =SLOT4 << 4;
    //NRF_LOG_RAW_INFO("Reading Multi_LED_Mode_Control2 for SLOT2 : ");
    Multi_LED_Mode_Control2 = Read(Multi_LED_Mode_Control2ADD) ;
    Multi_LED_Mode_Control2 = (Multi_LED_Mode_Control2 & SLOT4_MASK) | SLOT4 ;

    Send( Multi_LED_Mode_Control2ADD,Multi_LED_Mode_Control2);
    //NRF_LOG_RAW_INFO("Comfirm Multi_LED_Mode_Control2 for SLOT2 : ");
    Multi_LED_Mode_Control2 = Read(Multi_LED_Mode_Control2ADD) ;
    }

    bsp_board_init(BSP_INIT_LEDS);
    Readall();
    Softreset();
    Readall();

    bsp_board_led_invert(0);
    Enablefiforollover();
    ConfigureSampleAverage(0x02); //Sample Average 4 ; FOR SPO2
    Setmode(0x03); // 2 is red only, 3 is red + IR , 7 is Green + Red + IR ; ledMode = 2;
    Spo2adcrange(0x01); //2048 in arduino.
    Spo2samplerate(0x01); // 50 in arduino.
    Ledpulsewidth(0x03); // pulse Width is us ms ;
    //if 1 led = > 1 slot and put Red in it, if 2 leds , 2 slots and put IR in second one, if 3 slots , put Red in first, IR in second and green in third.
    //we have red only so: ( RED 0x01, IR 0x02, Green 0x03)
    slot1(0x01);
    slot2(0x02);
    slot3(0x03);
    Led1pulseamplitude(0x1F);
    Led2pulseamplitude(0x1F);
    Led3pulseamplitude(0x1F);
    bsp_board_led_invert(0);
    bsp_board_led_invert(3);


    NRF_LOG_FLUSH();


    //TESTING BEAT STUFF//
    int16_t IR_AC_Max = 20;
    int16_t IR_AC_Min = -20;
    //int16_t example1 = 0;
    int16_t IR_AC_Signal_Previous;
    int16_t IR_AC_Signal_min = 0;
    int16_t IR_AC_Signal_max = 0;
    int16_t IR_Average_Estimated;

    int16_t positiveEdge = 0;
    int16_t negativeEdge = 0;
    int32_t ir_avg_reg = 0;

    int16_t cbuf[32];
    uint8_t offset = 0;
    static const uint16_t FIRCoeffs[12] = {172, 321, 579, 927, 1360, 1858, 2390, 2916, 3391, 3768, 4012, 4096};

    // Average DC Estimator
    int16_t averageDCEstimator(int32_t *p, uint16_t x)
    {
    *p += ((((long) x << 15) - *p) >> 4);
    return (*p >> 15);
    }

    int32_t mul16(int16_t x, int16_t y)
    {
    return((long)x * (long)y);
    }
    // Low Pass FIR Filter
    int16_t lowPassFIRFilter(int16_t din)
    {
    cbuf[offset] = din;

    int32_t z = mul16(FIRCoeffs[11], cbuf[(offset - 11) & 0x1F]);

    for (uint8_t i = 0 ; i < 11 ; i++)
    {
    z += mul16(FIRCoeffs[i], cbuf[(offset - i) & 0x1F] + cbuf[(offset - 22 + i) & 0x1F]);
    }

    offset++;
    offset %= 32; //Wrap condition

    return(z >> 15);
    }

    // Heart Rate Monitor functions takes a sample value and the sample number
    // Returns true if a beat is detected
    // A running average of four samples is recommended for display on the screen.
    bool checkForBeat(int32_t sample)
    {
    bool beatDetected = false;

    // Save current state
    IR_AC_Signal_Previous = example1;

    //This is good to view for debugging
    //Serial.print("Signal_Current: ");
    //Serial.println(example);

    // Process next data sample
    IR_Average_Estimated = averageDCEstimator(&ir_avg_reg, sample);
    example1 = lowPassFIRFilter(sample - IR_Average_Estimated);

    // Detect positive zero crossing (rising edge)
    if ((IR_AC_Signal_Previous < 0) & (example1 >= 0))
    {

    IR_AC_Max = IR_AC_Signal_max; //Adjust our AC max and min
    IR_AC_Min = IR_AC_Signal_min;

    positiveEdge = 1;
    negativeEdge = 0;
    IR_AC_Signal_max = 0;

    //if ((IR_AC_Max - IR_AC_Min) > 100 & (IR_AC_Max - IR_AC_Min) < 1000)
    if ((IR_AC_Max - IR_AC_Min) > 20 & (IR_AC_Max - IR_AC_Min) < 1000)
    {
    //Heart beat!!!
    beatDetected = true;
    }
    }

    // Detect negative zero crossing (falling edge)
    if ((IR_AC_Signal_Previous > 0) & (example1 <= 0))
    {
    positiveEdge = 0;
    negativeEdge = 1;
    IR_AC_Signal_min = 0;
    }

    // Find Maximum value in positive cycle
    if (positiveEdge & (example1 > IR_AC_Signal_Previous))
    {
    IR_AC_Signal_max = example1;
    }

    // Find Minimum value in negative cycle
    if (negativeEdge & (example1 < IR_AC_Signal_Previous))
    {
    IR_AC_Signal_min = example1;
    }

    return(beatDetected);
    }

    //end of Testing beat
    //rtc_config();
    //lfclk_config();


    uint8_t Readysamplesnumber()
    {
    uint8_t write;
    uint8_t read;
    uint8_t error;
    error = 0;
    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&FIFO_Read_PointerADD, 1, false);
    nrf_delay_ms(5);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &FIFO_Read_Pointer,1);
    nrf_delay_ms(5);
    if (err_code == NRF_SUCCESS)
    {
    read = FIFO_Read_Pointer;
    }
    if (err_code !=NRF_SUCCESS)
    {
    error = 1 ;
    }

    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&FIFO_Write_PointerADD, 1, false);
    nrf_delay_ms(5);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &FIFO_Write_Pointer,1);
    nrf_delay_ms(5);
    if (err_code == NRF_SUCCESS)
    {
    write = FIFO_Write_Pointer;
    }
    if (err_code !=NRF_SUCCESS)
    {
    error = 1 ;
    }
    if (error = 0 ){
    if ( write > read )
    {
    return write - read ;
    }
    if ( write < read )
    {
    return write+32 -read;
    }

    error =0;
    }
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    /////////////////////////////////////////////////////////////SPO2//////////////////////////////////////////////////////////////
    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////


    void maxim_sort_indices_descend( int32_t *pn_x, int32_t *pn_indx, int32_t n_size)
    /**
    * \brief Sort indices
    * \par Details
    * Sort indices according to descending order (insertion sort algorithm)
    *
    * \retval None
    */
    {
    int32_t i, j, n_temp;
    for (i = 1; i < n_size; i++) {
    n_temp = pn_indx[i];
    for (j = i; j > 0 && pn_x[n_temp] > pn_x[pn_indx[j-1]]; j--)
    pn_indx[j] = pn_indx[j-1];
    pn_indx[j] = n_temp;
    }
    }

    void maxim_sort_ascend(int32_t *pn_x, int32_t n_size)
    /**
    * \brief Sort array
    * \par Details
    * Sort array in ascending order (insertion sort algorithm)
    *
    * \retval None
    */
    {
    int32_t i, j, n_temp;
    for (i = 1; i < n_size; i++) {
    n_temp = pn_x[i];
    for (j = i; j > 0 && n_temp < pn_x[j-1]; j--)
    pn_x[j] = pn_x[j-1];
    pn_x[j] = n_temp;
    }
    }

    void maxim_remove_close_peaks(int32_t *pn_locs, int32_t *pn_npks, int32_t *pn_x, int32_t n_min_distance)
    /**
    * \brief Remove peaks
    * \par Details
    * Remove peaks separated by less than MIN_DISTANCE
    *
    * \retval None
    */
    {

    int32_t i, j, n_old_npks, n_dist;

    /* Order peaks from large to small */
    maxim_sort_indices_descend( pn_x, pn_locs, *pn_npks );

    for ( i = -1; i < *pn_npks; i++ ){
    n_old_npks = *pn_npks;
    *pn_npks = i+1;
    for ( j = i+1; j < n_old_npks; j++ ){
    n_dist = pn_locs[j] - ( i == -1 ? -1 : pn_locs[i] ); // lag-zero peak of autocorr is at index -1
    if ( n_dist > n_min_distance || n_dist < -n_min_distance )
    pn_locs[(*pn_npks)++] = pn_locs[j];
    }
    }

    // Resort indices int32_to ascending order
    maxim_sort_ascend( pn_locs, *pn_npks );
    }

    void maxim_peaks_above_min_height( int32_t *pn_locs, int32_t *n_npks, int32_t *pn_x, int32_t n_size, int32_t n_min_height )
    /**
    * \brief Find peaks above n_min_height
    * \par Details
    * Find all peaks above MIN_HEIGHT
    *
    * \retval None
    */
    {
    int32_t i = 1, n_width;
    *n_npks = 0;

    while (i < n_size-1){
    if (pn_x[i] > n_min_height && pn_x[i] > pn_x[i-1]){ // find left edge of potential peaks
    n_width = 1;
    while (i+n_width < n_size && pn_x[i] == pn_x[i+n_width]) // find flat peaks
    n_width++;
    if (pn_x[i] > pn_x[i+n_width] && (*n_npks) < 15 ){ // find right edge of peaks
    pn_locs[(*n_npks)++] = i;
    // for flat peaks, peak location is left edge
    i += n_width+1;
    }
    else
    i += n_width;
    }
    else
    i++;
    }
    }
    void maxim_find_peaks( int32_t *pn_locs, int32_t *n_npks, int32_t *pn_x, int32_t n_size, int32_t n_min_height, int32_t n_min_distance, int32_t n_max_num )
    /**
    * \brief Find peaks
    * \par Details
    * Find at most MAX_NUM peaks above MIN_HEIGHT separated by at least MIN_DISTANCE
    *
    * \retval None
    */
    {
    maxim_peaks_above_min_height( pn_locs, n_npks, pn_x, n_size, n_min_height );
    maxim_remove_close_peaks( pn_locs, n_npks, pn_x, n_min_distance );
    //added a min here, because min doesn't exist
    if (*n_npks > n_max_num){
    *n_npks = n_max_num;
    }
    // *n_npks = min( *n_npks, n_max_num );
    if (*n_npks < n_max_num){
    *n_npks = *n_npks;
    }
    }


    void maxim_heart_rate_and_oxygen_saturation(uint32_t *pun_ir_buffer, int32_t n_ir_buffer_length, uint32_t *pun_red_buffer, int32_t *pn_spo2, int8_t *pch_spo2_valid,
    int32_t *pn_heart_rate, int8_t *pch_hr_valid)
    /**
    * \brief Calculate the heart rate and SpO2 level
    * \par Details
    * By detecting peaks of PPG cycle and corresponding AC/DC of red/infra-red signal, the an_ratio for the SPO2 is computed.
    * Since this algorithm is aiming for Arm M0/M3. formaula for SPO2 did not achieve the accuracy due to register overflow.
    * Thus, accurate SPO2 is precalculated and save longo uch_spo2_table[] per each an_ratio.
    *
    * \param[in] *pun_ir_buffer - IR sensor data buffer
    * \param[in] n_ir_buffer_length - IR sensor data buffer length
    * \param[in] *pun_red_buffer - Red sensor data buffer
    * \param[out] *pn_spo2 - Calculated SpO2 value
    * \param[out] *pch_spo2_valid - 1 if the calculated SpO2 value is valid
    * \param[out] *pn_heart_rate - Calculated heart rate value
    * \param[out] *pch_hr_valid - 1 if the calculated heart rate value is valid
    *
    * \retval None
    */
    {
    uint32_t un_ir_mean;
    int32_t k, n_i_ratio_count;
    int32_t i, n_exact_ir_valley_locs_count, n_middle_idx;
    int32_t n_th1, n_npks;
    int32_t an_ir_valley_locs[15] ;
    int32_t n_peak_interval_sum;

    int32_t n_y_ac, n_x_ac;
    int32_t n_spo2_calc;
    int32_t n_y_dc_max, n_x_dc_max;
    int32_t n_y_dc_max_idx = 0;
    int32_t n_x_dc_max_idx = 0;
    int32_t an_ratio[5], n_ratio_average;
    int32_t n_nume, n_denom ;

    // calculates DC mean and subtract DC from ir
    un_ir_mean =0;
    for (k=0 ; k<n_ir_buffer_length ; k++ ) un_ir_mean += pun_ir_buffer[k] ;
    un_ir_mean =un_ir_mean/n_ir_buffer_length ;

    // remove DC and invert signal so that we can use peak detector as valley detector
    for (k=0 ; k<n_ir_buffer_length ; k++ )
    an_x[k] = -1*(pun_ir_buffer[k] - un_ir_mean) ;

    // 4 pt Moving Average
    for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
    an_x[k]=( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3])/(int)4;
    }
    // calculate threshold
    n_th1=0;
    for ( k=0 ; k<BUFFER_SIZE ;k++){
    n_th1 += an_x[k];
    }
    n_th1= n_th1/ ( BUFFER_SIZE);
    if( n_th1<30) n_th1=30; // min allowed
    if( n_th1>60) n_th1=60; // max allowed

    for ( k=0 ; k<15;k++) an_ir_valley_locs[k]=0;
    // since we flipped signal, we use peak detector as valley detector
    maxim_find_peaks( an_ir_valley_locs, &n_npks, an_x, BUFFER_SIZE, n_th1, 4, 15 );//peak_height, peak_distance, max_num_peaks
    n_peak_interval_sum =0;
    if (n_npks>=2){
    for (k=1; k<n_npks; k++) n_peak_interval_sum += (an_ir_valley_locs[k] -an_ir_valley_locs[k -1] ) ;
    n_peak_interval_sum =n_peak_interval_sum/(n_npks-1);
    *pn_heart_rate =(int32_t)( (FreqS*60)/ n_peak_interval_sum );
    *pch_hr_valid = 1;
    }
    else {
    *pn_heart_rate = -999; // unable to calculate because # of peaks are too small
    *pch_hr_valid = 0;
    }

    // load raw value again for SPO2 calculation : RED(=y) and IR(=X)
    for (k=0 ; k<n_ir_buffer_length ; k++ ) {
    an_x[k] = pun_ir_buffer[k] ;
    an_y[k] = pun_red_buffer[k] ;
    }

    // find precise min near an_ir_valley_locs
    n_exact_ir_valley_locs_count =n_npks;

    //using exact_ir_valley_locs , find ir-red DC andir-red AC for SPO2 calibration an_ratio
    //finding AC/DC maximum of raw

    n_ratio_average =0;
    n_i_ratio_count = 0;
    for(k=0; k< 5; k++) an_ratio[k]=0;
    for (k=0; k< n_exact_ir_valley_locs_count; k++){
    if (an_ir_valley_locs[k] > BUFFER_SIZE ){
    *pn_spo2 = -999 ; // do not use SPO2 since valley loc is out of range
    *pch_spo2_valid = 0;
    return;
    }
    }
    // find max between two valley locations
    // and use an_ratio betwen AC compoent of Ir & Red and DC compoent of Ir & Red for SPO2
    for (k=0; k< n_exact_ir_valley_locs_count-1; k++){
    n_y_dc_max= -16777216 ;
    n_x_dc_max= -16777216;
    if (an_ir_valley_locs[k+1]-an_ir_valley_locs[k] >3){
    for (i=an_ir_valley_locs[k]; i< an_ir_valley_locs[k+1]; i++){
    if (an_x[i]> n_x_dc_max) {n_x_dc_max =an_x[i]; n_x_dc_max_idx=i;}
    if (an_y[i]> n_y_dc_max) {n_y_dc_max =an_y[i]; n_y_dc_max_idx=i;}
    }
    n_y_ac= (an_y[an_ir_valley_locs[k+1]] - an_y[an_ir_valley_locs[k] ] )*(n_y_dc_max_idx -an_ir_valley_locs[k]); //red
    n_y_ac= an_y[an_ir_valley_locs[k]] + n_y_ac/ (an_ir_valley_locs[k+1] - an_ir_valley_locs[k]) ;
    n_y_ac= an_y[n_y_dc_max_idx] - n_y_ac; // subracting linear DC compoenents from raw
    n_x_ac= (an_x[an_ir_valley_locs[k+1]] - an_x[an_ir_valley_locs[k] ] )*(n_x_dc_max_idx -an_ir_valley_locs[k]); // ir
    n_x_ac= an_x[an_ir_valley_locs[k]] + n_x_ac/ (an_ir_valley_locs[k+1] - an_ir_valley_locs[k]);
    n_x_ac= an_x[n_y_dc_max_idx] - n_x_ac; // subracting linear DC compoenents from raw
    n_nume=( n_y_ac *n_x_dc_max)>>7 ; //prepare X100 to preserve floating value
    n_denom= ( n_x_ac *n_y_dc_max)>>7;
    if (n_denom>0 && n_i_ratio_count <5 && n_nume != 0)
    {
    an_ratio[n_i_ratio_count]= (n_nume*100)/n_denom ; //formular is ( n_y_ac *n_x_dc_max) / ( n_x_ac *n_y_dc_max) ;
    n_i_ratio_count++;
    }
    }
    }
    // choose median value since PPG signal may varies from beat to beat
    maxim_sort_ascend(an_ratio, n_i_ratio_count);
    n_middle_idx= n_i_ratio_count/2;

    if (n_middle_idx >1)
    n_ratio_average =( an_ratio[n_middle_idx-1] +an_ratio[n_middle_idx])/2; // use median
    else
    n_ratio_average = an_ratio[n_middle_idx ];

    if( n_ratio_average>2 && n_ratio_average <184){
    n_spo2_calc= uch_spo2_table[n_ratio_average] ;
    *pn_spo2 = n_spo2_calc ;
    *pch_spo2_valid = 1;// float_SPO2 = -45.060*n_ratio_average* n_ratio_average/10000 + 30.354 *n_ratio_average/100 + 94.845 ; // for comparison with table
    }
    else{
    *pn_spo2 = -999 ; // do not use SPO2 since signal an_ratio is out of range
    *pch_spo2_valid = 0;
    }
    }


    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    /////////////////////////////////////////////////////////////SPO2//////////////////////////////////////////////////////////////
    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

    /*******************************************************************************************/
    /*********************************************************************************************/
    /********************************************************************************************/












    advertising_start();

    ret = app_usbd_power_events_enable();
    APP_ERROR_CHECK(ret);



    while(true)

    {

    uint8_t bufferLength = 100;

    for(uint8_t k =0 ; k < bufferLength ; k++)
    {


    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&FIFO_Write_PointerADD, 1, false);
    nrf_delay_ms(5);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &FIFO_Write_Pointer,1);
    nrf_delay_ms(5);
    if (err_code != NRF_SUCCESS)
    {
    NRF_LOG_INFO(" ERROR IN Write Pointer: 0x%x", FIFO_Write_Pointer);
    NRF_LOG_FLUSH();
    error = 1;
    }
    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&FIFO_Read_PointerADD, 1, false);
    nrf_delay_ms(5);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &FIFO_Read_Pointer,1);
    nrf_delay_ms(5);
    if (err_code != NRF_SUCCESS)
    {
    NRF_LOG_INFO(" ERROR IN Read Pointer 0x%x", FIFO_Read_Pointer);
    NRF_LOG_FLUSH();
    error = 1;
    }
    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&Over_Flow_CounterADD, 1, false);
    nrf_delay_ms(5);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &Over_Flow_Counter,1);
    nrf_delay_ms(5);
    if (err_code == NRF_SUCCESS)
    {
    // NRF_LOG_INFO(" Overflowed: 0x%x", Over_Flow_Counter);

    }

    if (FIFO_Write_Pointer > FIFO_Read_Pointer){ReadySamples = FIFO_Write_Pointer - FIFO_Read_Pointer;}
    if (FIFO_Write_Pointer < FIFO_Read_Pointer ){ReadySamples = FIFO_Write_Pointer+32 - FIFO_Read_Pointer;}
    if (FIFO_Write_Pointer == FIFO_Read_Pointer)
    {
    ReadySamples = 0;
    k--;
    }
    if (error == 1 )
    {
    ReadySamples = 0;
    k--;
    }
    if ( ReadySamples > 0){

    bsp_board_led_invert(3);

    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&FIFO_Data_RegisterADD, 1, false);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &FIFO_Data_Register,3*ReadySamples*lednumber);
    nrf_delay_ms(4);
    if (err_code == NRF_SUCCESS)
    {
    error = 0;
    uint8_t i=0;
    if (lednumber == 1)
    {
    for (i=0;i<ReadySamples*3;i=i+3)
    {
    Max_ADC = ((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2];
    example = (((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2]);
    redBuffer[k]=Max_ADC;
    NRF_LOG_INFO("RED : %d,Samples %d %d %d %d", Max_ADC, ReadySamples, Over_Flow_Counter,FIFO_Read_Pointer,FIFO_Write_Pointer );

    NRF_LOG_FLUSH();
    bsp_board_led_invert(3);

    }
    }
    if ( lednumber == 2 )
    {
    for (i=0;i<ReadySamples*3*2;i=i+6)
    {
    Max_ADC = ((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2];
    Max_ADC2 = ((uint32_t)FIFO_Data_Register[i+3] << 16) | ((uint32_t)FIFO_Data_Register[i+4] << 8) | FIFO_Data_Register[i+5];
    // example = (((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2]);
    redBuffer[k]=Max_ADC;
    irBuffer[k]=Max_ADC2;
    //NRF_LOG_INFO("RED : %d,Samples %d %d %d %d", Max_ADC, ReadySamples, Over_Flow_Counter,FIFO_Read_Pointer,FIFO_Write_Pointer );
    //NRF_LOG_INFO("IR : %d,Samples %d %d %d %d", Max_ADC2, ReadySamples, Over_Flow_Counter,FIFO_Read_Pointer,FIFO_Write_Pointer );

    NRF_LOG_FLUSH();
    bsp_board_led_invert(3);
    }

    }
    if (lednumber == 3 )
    {
    for (i=0;i<ReadySamples*3*3;i=i+9)
    {
    Max_ADC = ((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2];
    Max_ADC2 = ((uint32_t)FIFO_Data_Register[i+3] << 16) | ((uint32_t)FIFO_Data_Register[i+4] << 8) | FIFO_Data_Register[i+5];
    Max_ADC3 = ((uint32_t)FIFO_Data_Register[i+6] << 16) | ((uint32_t)FIFO_Data_Register[i+7] << 8) | FIFO_Data_Register[i+8];
    redBuffer[k]=Max_ADC;
    irBuffer[k]=Max_ADC2;
    greenBuffer[k]=Max_ADC3;
    // example = (((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2]);
    //NRF_LOG_INFO("RED : %d,Samples %d %d %d %d", Max_ADC, ReadySamples, Over_Flow_Counter,FIFO_Read_Pointer,FIFO_Write_Pointer );
    // NRF_LOG_INFO("IR : %d,Samples %d %d %d %d", Max_ADC2, ReadySamples, Over_Flow_Counter,FIFO_Read_Pointer,FIFO_Write_Pointer );
    // NRF_LOG_INFO("GREEN : %d,Samples %d %d %d %d", Max_ADC3, ReadySamples, Over_Flow_Counter,FIFO_Read_Pointer,FIFO_Write_Pointer );

    NRF_LOG_FLUSH();
    bsp_board_led_invert(3);
    }


    }



    }


    }
    }
    //timer=nrfx_rtc_counter_get(&rtc);
    maxim_heart_rate_and_oxygen_saturation(irBuffer, bufferLength, redBuffer, &spo2, &validSPO2, &heartRate, &validHeartRate);

    //Continuously taking samples from MAX30102. Heart rate and SpO2 are calculated every 1 second
    while (1)
    {
    //dumping the first 25 sets of samples in the memory and shift the last 75 sets of samples to the top
    for (uint8_t k = 25; k < 100; k++)
    {
    redBuffer[k - 25] = redBuffer[k];
    irBuffer[k - 25] = irBuffer[k];
    }

    //take 25 sets of samples before calculating the heart rate.
    for (uint8_t k = 75; k < 100; k++)
    {



    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&FIFO_Write_PointerADD, 1, false);
    nrf_delay_ms(5);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &FIFO_Write_Pointer,1);
    nrf_delay_ms(5);
    if (err_code != NRF_SUCCESS)
    {
    NRF_LOG_INFO(" ERROR IN Write Pointer: 0x%x", FIFO_Write_Pointer);
    NRF_LOG_FLUSH();
    error = 1;
    }
    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&FIFO_Read_PointerADD, 1, false);
    nrf_delay_ms(5);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &FIFO_Read_Pointer,1);
    nrf_delay_ms(5);
    if (err_code != NRF_SUCCESS)
    {
    NRF_LOG_INFO(" ERROR IN Read Pointer 0x%x", FIFO_Read_Pointer);
    NRF_LOG_FLUSH();
    error = 1;
    }
    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&Over_Flow_CounterADD, 1, false);
    nrf_delay_ms(5);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &Over_Flow_Counter,1);
    nrf_delay_ms(5);
    if (err_code == NRF_SUCCESS)
    {
    // NRF_LOG_INFO(" Overflowed: 0x%x", Over_Flow_Counter);

    }
    if (FIFO_Write_Pointer > FIFO_Read_Pointer){ReadySamples = FIFO_Write_Pointer - FIFO_Read_Pointer;}
    if (FIFO_Write_Pointer < FIFO_Read_Pointer ){ReadySamples = FIFO_Write_Pointer+32 - FIFO_Read_Pointer;}
    if (FIFO_Write_Pointer == FIFO_Read_Pointer)
    {
    ReadySamples = 0;
    k--;
    }
    if (error == 1 )
    {
    ReadySamples = 0;
    k--;
    }
    if ( ReadySamples > 0){

    bsp_board_led_invert(3);

    err_code = nrf_drv_twi_tx(&m_twi, MX30105_ADDR,&FIFO_Data_RegisterADD, 1, false);
    err_code = nrf_drv_twi_rx(&m_twi, MX30105_ADDR, &FIFO_Data_Register,3*ReadySamples*lednumber);
    nrf_delay_ms(4);
    if (err_code == NRF_SUCCESS)
    {
    error = 0;
    uint8_t i=0;
    if (lednumber == 1)
    {
    for (i=0;i<ReadySamples*3;i=i+3)
    {
    Max_ADC = ((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2];
    example = (((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2]);
    redBuffer[k]=Max_ADC;
    NRF_LOG_INFO("RED : %d,Samples %d %d %d %d", Max_ADC, ReadySamples, Over_Flow_Counter,FIFO_Read_Pointer,FIFO_Write_Pointer );

    NRF_LOG_FLUSH();
    bsp_board_led_invert(3);

    }
    }
    if ( lednumber == 2 )
    {
    for (i=0;i<ReadySamples*3*2;i=i+6)
    {
    Max_ADC = ((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2];
    Max_ADC2 = ((uint32_t)FIFO_Data_Register[i+3] << 16) | ((uint32_t)FIFO_Data_Register[i+4] << 8) | FIFO_Data_Register[i+5];
    redBuffer[k]=Max_ADC;
    irBuffer[k]=Max_ADC2;

    NRF_LOG_FLUSH();
    bsp_board_led_invert(3);
    }

    }
    if (lednumber == 3 )
    {
    for (i=0;i<ReadySamples*3*3;i=i+9)
    {
    Max_ADC = ((uint32_t)FIFO_Data_Register[i] << 16) | ((uint32_t)FIFO_Data_Register[i+1] << 8) | FIFO_Data_Register[i+2];
    Max_ADC2 = ((uint32_t)FIFO_Data_Register[i+3] << 16) | ((uint32_t)FIFO_Data_Register[i+4] << 8) | FIFO_Data_Register[i+5];
    Max_ADC3 = ((uint32_t)FIFO_Data_Register[i+6] << 16) | ((uint32_t)FIFO_Data_Register[i+7] << 8) | FIFO_Data_Register[i+8];
    redBuffer[k]=Max_ADC;
    irBuffer[k]=Max_ADC2;
    greenBuffer[k]=Max_ADC3;

    NRF_LOG_FLUSH();
    bsp_board_led_invert(3);
    }


    }



    }


    }


    maxim_heart_rate_and_oxygen_saturation(irBuffer, bufferLength, redBuffer, &spo2, &validSPO2, &heartRate, &validHeartRate);
    NRF_LOG_INFO(" %d ", spo2 );

    BPM = (int32_t)60000/(int32_t)heartRate;

    }






    // Enter main loop
    for (;;)
    {
    while (app_usbd_event_queue_process())

    {sendcom("hello");

    }}


    }}


    idle_state_handle();



    }

  • nikola said:
    Thank you for answering me

    No problem at all, I am happy to help!

    nikola said:
    I solved this error

    I am glad to hear that you were able to identify and resolve the error!

    Before we proceed with the question, please reformat the code you have posted so that it is readable. Please use the Insert -> Code option when sharing code here on DevZone.

    Briefly looking through the code you have posted I also notice that you do not check all your returned error codes. If you do not do this, you will not be alerted in the case that a function call fails, which might mean that you have to proceed differently.
    Please make sure that all returned error codes are passed to an APP_ERROR_CHECK or similar, so that you will know in the case that you will know if the function call failed, for whatever reason.

    Furthermore, if you make sure that DEBUG is defined in your preprocessor defines the logger will output a detailed error message to your log whenever a non-NRF_SUCCESS error code is passed to an APP_ERROR_CHECK. Please see the included image for instruction on how you may add the DEBUG define.

    Lastly, I also notice that you use a lot of magic numbers in your code. I would strongly advice that you refrain from doing so. This will drastically increase both readability and maintainability of your code.

    Best regards,
    Karl

  • I have already tried to insert my code and and I cannot

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