PPI with multiple SAADCs and multiple TIMERs

[Duy]

Dear Nordic Support,

I am using PPI to link 2 timers (10ms & 5s) with 2 SAADC channel (AIN1 - channel 0 & AIN2 - channel 1). 

The nrf_drv_saadc_init function is only called once so it means there is only one callback for the sampling event. In case I am using 2 channels, how do I know that which channel has completed its sampling event in the callback function? When I printed out the ADC value, all I saw is CH0 and CH1 are read at the same time while I expect CH0 every 10ms and CH1 every 5s.

I am using nRF52840 + nRF5 SDK 15.3 + SD 6.1.1.

Thank you and best regards,

           Duy

            

void saadc_transducer_callback(nrf_drv_saadc_evt_t const * p_event)
{
    uint8_t idx;

    if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
    {
        APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, RAW_ADC_BUFF_SIZE));

        NRF_LOG_INFO("T.ADC event number: %d", (int)m_transducer_evt_counter);

        for (idx = 0; idx < RAW_ADC_BUFF_SIZE; idx++)
        {
            NRF_LOG_INFO("%d", p_event->data.done.p_buffer[idx]);
        }
        m_transducer_evt_counter++;
    }
}


static void saadc_sampling_event_init(void)
{
    uint32_t transducer_timer_compare_event_addr, battery_timer_compare_event_addr;
    uint32_t saadc_sample_task_addr;

    APP_ERROR_CHECK(nrf_drv_ppi_init());

    nrf_drv_timer_enable(&TRANSDUCER_TIMER);
    nrf_drv_timer_enable(&BATTERY_TIMER);

    transducer_timer_compare_event_addr = nrf_drv_timer_compare_event_address_get(&TRANSDUCER_TIMER, NRF_TIMER_CC_CHANNEL0);
    battery_timer_compare_event_addr = nrf_drv_timer_compare_event_address_get(&BATTERY_TIMER, NRF_TIMER_CC_CHANNEL0);
    
    saadc_sample_task_addr = nrf_drv_saadc_sample_task_get();
    /* Setup ppi channel so that timer compare event is triggering sample tasks in SAADC */
    APP_ERROR_CHECK(nrf_drv_ppi_channel_alloc(&TORQUE_SAADC_TIMER_PPI_CHANNEL));
    APP_ERROR_CHECK(nrf_drv_ppi_channel_alloc(&BATTERY_SAADC_TIMER_PPI_CHANNEL));

    APP_ERROR_CHECK(nrf_drv_ppi_channel_assign(TORQUE_SAADC_TIMER_PPI_CHANNEL, transducer_timer_compare_event_addr, saadc_sample_task_addr));
    APP_ERROR_CHECK(nrf_drv_ppi_channel_assign(BATTERY_SAADC_TIMER_PPI_CHANNEL, battery_timer_compare_event_addr, saadc_sample_task_addr));
}


static void saadc_init(void)
{
    nrf_saadc_channel_config_t adc_channel_config = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN1);
    nrf_saadc_channel_config_t battery_channel_config = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN2);

    APP_ERROR_CHECK(nrf_drv_saadc_init(NULL, saadc_transducer_callback));

    APP_ERROR_CHECK(nrf_drv_saadc_channel_init(0, &adc_channel_config));
    APP_ERROR_CHECK(nrf_drv_saadc_channel_init(1, &battery_channel_config));

    APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(m_buffer_pool[0], RAW_ADC_BUFF_SIZE));
    APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(m_buffer_pool[1], RAW_ADC_BUFF_SIZE));
}

[Håkon Alseth]

Hi,

 

If you want one SAADC channel to run every 5ms, and another to run every 5 seconds, you need to use two timers.

This is because the timer itself will not count to 5 ms, fire the event for sampling your first channel, then run for another 4.995 seconds before triggering the event to sample your second channel.

Could you try to run a individual timer per event and see if that works better?

 

Kind regards,

Håkon

[Duy]

Hello Håkon Alseth,

Thank you for your answer, I am running 2 different timers running in different periods (10ms and 5s). If I run only 1 ADC channel + 1 TIMER with PPI, everything works fine.

Warm regards,

      Duy

#define APP_ADV_INTERVAL                32                                          /**< The advertising interval (in units of 0.625 ms. This value corresponds to 25 ms). */
#define ADC_ACQUISITION_INTERVAL        10          
#define BATTERY_LEVEL_MEAS_INTERVAL     10000                                       /**< Battery level measurement interval (ticks). */

#define APP_ADV_DURATION                18000                                       /**< The advertising duration (180 seconds) in units of 10 milliseconds. */

static void saadc_init(void)
{
    nrf_saadc_channel_config_t adc_channel_config = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN1);
    nrf_saadc_channel_config_t battery_channel_config = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN2);

    APP_ERROR_CHECK(nrf_drv_saadc_init(NULL, saadc_transducer_callback));
//    APP_ERROR_CHECK(nrf_drv_saadc_init(NULL, saadc_battery_callback));

    APP_ERROR_CHECK(nrf_drv_saadc_channel_init(0, &adc_channel_config));
    APP_ERROR_CHECK(nrf_drv_saadc_channel_init(1, &battery_channel_config));

    APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(m_buffer_pool[0], RAW_ADC_BUFF_SIZE));
    APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(m_buffer_pool[1], RAW_ADC_BUFF_SIZE));
}


/**@brief Function for the Timer initialization.
 *
 * @details Initializes the timer module. This creates and starts application timers.
 */
static void timers_init(void)
{
    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;

    /* Enable app timer */
    APP_ERROR_CHECK(app_timer_init());

    /* Create ADC timer */
    APP_ERROR_CHECK(nrf_drv_timer_init(&TRANSDUCER_TIMER, &timer_cfg, adc_acquisition_timeout_handler));
    nrf_drv_timer_extended_compare(&TRANSDUCER_TIMER, NRF_TIMER_CC_CHANNEL0, nrf_drv_timer_ms_to_ticks(&TRANSDUCER_TIMER, ADC_ACQUISITION_INTERVAL), NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);

    /* Configure BATTERY TIMER */
    APP_ERROR_CHECK(nrf_drv_timer_init(&BATTERY_TIMER, &timer_cfg, battery_level_meas_timeout_handler));
    nrf_drv_timer_extended_compare(&BATTERY_TIMER, NRF_TIMER_CC_CHANNEL0, nrf_drv_timer_ms_to_ticks(&BATTERY_TIMER, BATTERY_LEVEL_MEAS_INTERVAL), NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);
}


static void saadc_sampling_event_init(void)
{
    uint32_t transducer_timer_compare_event_addr, battery_timer_compare_event_addr;
    uint32_t saadc_sample_task_addr;

    APP_ERROR_CHECK(nrf_drv_ppi_init());

    nrf_drv_timer_enable(&TRANSDUCER_TIMER);
    nrf_drv_timer_enable(&BATTERY_TIMER);

    transducer_timer_compare_event_addr = nrf_drv_timer_compare_event_address_get(&TRANSDUCER_TIMER, NRF_TIMER_CC_CHANNEL0);
    battery_timer_compare_event_addr = nrf_drv_timer_compare_event_address_get(&BATTERY_TIMER, NRF_TIMER_CC_CHANNEL0);
    
    saadc_sample_task_addr = nrf_drv_saadc_sample_task_get();
    /* Setup ppi channel so that timer compare event is triggering sample tasks in SAADC */
    APP_ERROR_CHECK(nrf_drv_ppi_channel_alloc(&TORQUE_SAADC_TIMER_PPI_CHANNEL));
    APP_ERROR_CHECK(nrf_drv_ppi_channel_alloc(&BATTERY_SAADC_TIMER_PPI_CHANNEL));

    APP_ERROR_CHECK(nrf_drv_ppi_channel_assign(TORQUE_SAADC_TIMER_PPI_CHANNEL, transducer_timer_compare_event_addr, saadc_sample_task_addr));
    APP_ERROR_CHECK(nrf_drv_ppi_channel_assign(BATTERY_SAADC_TIMER_PPI_CHANNEL, battery_timer_compare_event_addr, saadc_sample_task_addr));
}

[Håkon Alseth]

Hi Duy,

  

Duy said:

Thank you for your answer, I am running 2 different timers running in different periods (10ms and 5s). If I run only 1 ADC channel + 1 TIMER with PPI, everything works fine.

 Yes, that is expected to work. In your initial code, you are using one timer (with 2 capture/compare events), which will cause the timer to clear itself on the last event, thus you end up in a scenario where it runs the first SAADC task after 5 ms, and the next one after 4.995 seconds, before the timer itself is cleared.

 

If you add another timer instance to your application, it should work with 2 SAADC channels + 2 TIMERs.

 

Kind regards,

Håkon

[Duy]

Hello Håkon Alseth,

Please have a look at my code in main.c and my configuration is sdk_config.h file. Sorry for make it not clear but I still don't get it work. I enabled TIMER1 and TIMER2.

The TRANSDUCER_TIMER is TIMER1 and BATTERY_TIMER is TIMER2. I think I have to clear a register to get this to work.

const nrf_drv_timer_t TRANSDUCER_TIMER = NRF_DRV_TIMER_INSTANCE(1);                 /**< ADC timer. */
const nrf_drv_timer_t BATTERY_TIMER = NRF_DRV_TIMER_INSTANCE(2);                    /**< Battery timer. */

Thank you and best regards, 

            Duy

Fullscreen 55478.main.c Download

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/** @file
 *
 * @defgroup ble_sdk_app_hts_main main.c
 * @{
 * @ingroup ble_sdk_app_hts
 * @brief Health Thermometer Service Sample Application main file.
 *
 * This file contains the source code for a sample application using the Health Thermometer service
 * It also includes the sample code for Battery and Device Information services.
 * This application uses the @ref srvlib_conn_params module.
 */

#include "main.h"


#define MIN_BATTERY_LEVEL               81                                          /**< Minimum battery level as returned by the simulated measurement function. */
#define MAX_BATTERY_LEVEL               100                                         /**< Maximum battery level as returned by the simulated measurement function. */
#define BATTERY_LEVEL_INCREMENT         1                                           /**< Value by which the battery level is incremented/decremented for each call to the simulated measurement function. */

#define TEMP_TYPE_AS_CHARACTERISTIC     0                                           /**< Determines if temperature type is given as characteristic (1) or as a field of measurement (0). */

#define MIN_CELCIUS_DEGREES             3688                                        /**< Minimum temperature in celcius for use in the simulated measurement function (multiplied by 100 to avoid floating point arithmetic). */
#define MAX_CELCIUS_DEGRESS             3972                                        /**< Maximum temperature in celcius for use in the simulated measurement function (multiplied by 100 to avoid floating point arithmetic). */
#define CELCIUS_DEGREES_INCREMENT       36                                          /**< Value by which temperature is incremented/decremented for each call to the simulated measurement function (multiplied by 100 to avoid floating point arithmetic). */


const nrf_drv_timer_t TRANSDUCER_TIMER = NRF_DRV_TIMER_INSTANCE(1);                 /**< ADC timer. */
const nrf_drv_timer_t BATTERY_TIMER = NRF_DRV_TIMER_INSTANCE(2);                    /**< Battery timer. */
static nrf_ppi_channel_t TORQUE_SAADC_TIMER_PPI_CHANNEL;
static nrf_ppi_channel_t BATTERY_SAADC_TIMER_PPI_CHANNEL;
BLE_BAS_DEF(m_bas);                                                                 /**< Structure used to identify the battery service. */
BLE_HTS_DEF(m_hts);                                                                 /**< Structure used to identify the health thermometer service. */
NRF_BLE_GATT_DEF(m_gatt);                                                           /**< GATT module instance. */
NRF_BLE_QWR_DEF(m_qwr);                                                             /**< Context for the Queued Write module.*/
BLE_ADVERTISING_DEF(m_advertising);                                                 /**< Advertising module instance. */

static uint16_t          m_conn_handle = BLE_CONN_HANDLE_INVALID;                   /**< Handle of the current connection. */
static bool              m_hts_meas_ind_conf_pending = false;                       /**< Flag to keep track of when an indication confirmation is pending. */
static sensorsim_cfg_t   m_battery_sim_cfg;                                         /**< Battery Level sensor simulator configuration. */
static sensorsim_state_t m_battery_sim_state;                                       /**< Battery Level sensor simulator state. */
static sensorsim_cfg_t   m_temp_celcius_sim_cfg;                                    /**< Temperature simulator configuration. */
static sensorsim_state_t m_temp_celcius_sim_state;                                  /**< Temperature simulator state. */
static bool              m_device_connected = false;
static ble_uuid_t m_adv_uuids[] =                                                   /**< Universally unique service identifiers. */
{
    {BLE_UUID_HEALTH_THERMOMETER_SERVICE, BLE_UUID_TYPE_BLE},
    {BLE_UUID_BATTERY_SERVICE, BLE_UUID_TYPE_BLE},
    {BLE_UUID_DEVICE_INFORMATION_SERVICE, BLE_UUID_TYPE_BLE}
};

static nrf_saadc_value_t m_buffer_pool[2][RAW_ADC_BUFF_SIZE];

static uint32_t          m_transducer_evt_counter;
static uint32_t          m_bat_evt_counter;


static void advertising_start(bool erase_bonds);
static void temperature_measurement_send(void);


/**@brief Callback function for asserts in the SoftDevice.
 *
 * @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 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] 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 handling Peer Manager events.
 *
 * @param[in] p_evt  Peer Manager event.
 */
static void pm_evt_handler(pm_evt_t const * p_evt)
{
    bool is_indication_enabled;

    pm_handler_on_pm_evt(p_evt);
    pm_handler_flash_clean(p_evt);

    switch (p_evt->evt_id)
    {
        case PM_EVT_CONN_SEC_SUCCEEDED:
            // Send a single temperature measurement if indication is enabled.
            // NOTE: For this to work, make sure ble_hts_on_ble_evt() is called before
            // pm_evt_handler() in ble_evt_dispatch().
            APP_ERROR_CHECK(ble_hts_is_indication_enabled(&m_hts, &is_indication_enabled));
            if (is_indication_enabled)
            {
                temperature_measurement_send();
            }
            break;

        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            advertising_start(false);
            break;

        default:
            break;
    }
}


/**@brief Function for performing a battery measurement, and update the Battery Level characteristic in the Battery Service.
 */
static void battery_level_update(void)
{
    ret_code_t err_code;
    uint8_t  battery_level;

    battery_level = (uint8_t)sensorsim_measure(&m_battery_sim_state, &m_battery_sim_cfg);
  
    err_code = ble_bas_battery_level_update(&m_bas, battery_level, BLE_CONN_HANDLE_ALL);
    if ((err_code != NRF_SUCCESS) &&
        (err_code != NRF_ERROR_INVALID_STATE) &&
        (err_code != NRF_ERROR_RESOURCES) &&
        (err_code != NRF_ERROR_BUSY) &&
        (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
       )
    {
        APP_ERROR_HANDLER(err_code);
    }
}


/**@brief Function for handling the Battery measurement timer timeout.
 *
 * @details This function will be called each time the battery level measurement timer expires.
 *
 * @param[in] p_context   Pointer used for passing some arbitrary information (context) from the
 *                        app_start_timer() call to the timeout handler.
 */
uint16_t counter;
static void adc_acquisition_timeout_handler(nrf_timer_event_t event_type, void *p_context)
{
    switch (event_type)
    {
        case NRF_TIMER_EVENT_COMPARE0:
        {    
            counter++;
            if (m_conn_handle != BLE_CONN_HANDLE_INVALID)
            {
                /* Update torque */
            }
            break;
        }

        default: break;
    }
}


/**@brief Function for handling the Battery measurement timer timeout.
 *
 * @details This function will be called each time the battery level measurement timer expires.
 *
 * @param[in] p_context   Pointer used for passing some arbitrary information (context) from the
 *                        app_start_timer() call to the timeout handler.
 */
uint16_t counter1;
static void battery_level_meas_timeout_handler(nrf_timer_event_t event_type, void *p_context)
{
    switch (event_type)
    {
        case NRF_TIMER_EVENT_COMPARE0:
        {    
            counter1++;
            if (m_conn_handle != BLE_CONN_HANDLE_INVALID)
            {
                temperature_measurement_send();
                battery_level_update();
            }
            break;
        }

        default: break;
    }
}


static void saadc_transducer_callback(nrf_drv_saadc_evt_t const * p_event)
{
    uint8_t idx;

    if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
    {
        APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, RAW_ADC_BUFF_SIZE));
      
        NRF_LOG_INFO("ADC channel %d event number: %d",p_event->data.limit.channel, (int)m_transducer_evt_counter);

        for (idx = 0; idx < RAW_ADC_BUFF_SIZE; idx++)
        {
            NRF_LOG_INFO("%d", p_event->data.done.p_buffer[idx]);
        }
        m_transducer_evt_counter++;
    }
}


//static void saadc_battery_callback(nrf_drv_saadc_evt_t const * p_event)
//{
//    uint8_t idx;
//
//    if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
//    {
//        APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, RAW_BATTERY_BUFF_SIZE));
//
//        NRF_LOG_INFO("BATTERY event number: %d", (int)m_bat_evt_counter);
//
//        for (idx = 0; idx < RAW_BATTERY_BUFF_SIZE; idx++)
//        {
//            NRF_LOG_INFO("%d", p_event->data.done.p_buffer[idx]);
//        }
//        m_bat_evt_counter++;
//    }
//}


/**@brief Function for populating simulated health thermometer measurement.
 */
static void hts_sim_measurement(ble_hts_meas_t * p_meas)
{
    static ble_date_time_t time_stamp = { 2012, 12, 5, 11, 50, 0 };

    uint32_t celciusX100;

    p_meas->temp_in_fahr_units = false;
    p_meas->time_stamp_present = true;
    p_meas->temp_type_present  = (TEMP_TYPE_AS_CHARACTERISTIC ? false : true);

    celciusX100 = sensorsim_measure(&m_temp_celcius_sim_state, &m_temp_celcius_sim_cfg);

    p_meas->temp_in_celcius.exponent = -2;
    p_meas->temp_in_celcius.mantissa = celciusX100;
    p_meas->temp_in_fahr.exponent    = -2;
    p_meas->temp_in_fahr.mantissa    = (32 * 100) + ((celciusX100 * 9) / 5);
    p_meas->time_stamp               = time_stamp;
    p_meas->temp_type                = BLE_HTS_TEMP_TYPE_FINGER;

    // update simulated time stamp
    time_stamp.seconds += 27;
    if (time_stamp.seconds > 59)
    {
        time_stamp.seconds -= 60;
        time_stamp.minutes++;
        if (time_stamp.minutes > 59)
        {
            time_stamp.minutes = 0;
        }
    }
}


static void saadc_init(void)
{
    nrf_saadc_channel_config_t adc_channel_config = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN1);
    nrf_saadc_channel_config_t battery_channel_config = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN2);

    APP_ERROR_CHECK(nrf_drv_saadc_init(NULL, saadc_transducer_callback));
//    APP_ERROR_CHECK(nrf_drv_saadc_init(NULL, saadc_battery_callback));

    APP_ERROR_CHECK(nrf_drv_saadc_channel_init(0, &adc_channel_config));
    APP_ERROR_CHECK(nrf_drv_saadc_channel_init(1, &battery_channel_config));

    APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(m_buffer_pool[0], RAW_ADC_BUFF_SIZE));
    APP_ERROR_CHECK(nrf_drv_saadc_buffer_convert(m_buffer_pool[1], RAW_ADC_BUFF_SIZE));
}


/**@brief Function for the Timer initialization.
 *
 * @details Initializes the timer module. This creates and starts application timers.
 */
static void timers_init(void)
{
    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;

    /* Enable app timer */
    APP_ERROR_CHECK(app_timer_init());

    /* Create ADC timer */
    APP_ERROR_CHECK(nrf_drv_timer_init(&TRANSDUCER_TIMER, &timer_cfg, adc_acquisition_timeout_handler));
    nrf_drv_timer_extended_compare(&TRANSDUCER_TIMER, NRF_TIMER_CC_CHANNEL0, nrf_drv_timer_ms_to_ticks(&TRANSDUCER_TIMER, ADC_ACQUISITION_INTERVAL), NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);

    /* Configure BATTERY TIMER */
    APP_ERROR_CHECK(nrf_drv_timer_init(&BATTERY_TIMER, &timer_cfg, battery_level_meas_timeout_handler));
    nrf_drv_timer_extended_compare(&BATTERY_TIMER, NRF_TIMER_CC_CHANNEL0, nrf_drv_timer_ms_to_ticks(&BATTERY_TIMER, BATTERY_LEVEL_MEAS_INTERVAL), NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);
}


static void saadc_sampling_event_init(void)
{
    uint32_t transducer_timer_compare_event_addr, battery_timer_compare_event_addr;
    uint32_t saadc_sample_task_addr;

    APP_ERROR_CHECK(nrf_drv_ppi_init());

    nrf_drv_timer_enable(&TRANSDUCER_TIMER);
    nrf_drv_timer_enable(&BATTERY_TIMER);

    transducer_timer_compare_event_addr = nrf_drv_timer_compare_event_address_get(&TRANSDUCER_TIMER, NRF_TIMER_CC_CHANNEL0);
    battery_timer_compare_event_addr = nrf_drv_timer_compare_event_address_get(&BATTERY_TIMER, NRF_TIMER_CC_CHANNEL0);
    
    saadc_sample_task_addr = nrf_drv_saadc_sample_task_get();
    /* Setup ppi channel so that timer compare event is triggering sample tasks in SAADC */
    APP_ERROR_CHECK(nrf_drv_ppi_channel_alloc(&TORQUE_SAADC_TIMER_PPI_CHANNEL));
    APP_ERROR_CHECK(nrf_drv_ppi_channel_alloc(&BATTERY_SAADC_TIMER_PPI_CHANNEL));

    APP_ERROR_CHECK(nrf_drv_ppi_channel_assign(TORQUE_SAADC_TIMER_PPI_CHANNEL, transducer_timer_compare_event_addr, saadc_sample_task_addr));
    APP_ERROR_CHECK(nrf_drv_ppi_channel_assign(BATTERY_SAADC_TIMER_PPI_CHANNEL, battery_timer_compare_event_addr, saadc_sample_task_addr));
}


static void saadc_sampling_event_enable(void)
{
    APP_ERROR_CHECK(nrf_drv_ppi_channel_enable(TORQUE_SAADC_TIMER_PPI_CHANNEL));

    APP_ERROR_CHECK(nrf_drv_ppi_channel_enable(BATTERY_SAADC_TIMER_PPI_CHANNEL));
}


/**@brief Function for the GAP initialization.
 *
 * @details This function sets up all the necessary GAP (Generic Access Profile) parameters of the
 *          device including the device name, appearance, and the preferred connection parameters.
 */
static void gap_params_init(void)
{
    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);

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

    APP_ERROR_CHECK(sd_ble_gap_appearance_set(BLE_APPEARANCE_GENERIC_THERMOMETER));

    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;

    APP_ERROR_CHECK(sd_ble_gap_ppcp_set(&gap_conn_params));
}


/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void)
{
    APP_ERROR_CHECK(nrf_ble_gatt_init(&m_gatt, NULL));
}


/**@brief Function for simulating and sending one Temperature Measurement.
 */
static void temperature_measurement_send(void)
{
    ble_hts_meas_t simulated_meas;
    ret_code_t     err_code;

    if (!m_hts_meas_ind_conf_pending)
    {
        hts_sim_measurement(&simulated_meas);

        err_code = ble_hts_measurement_send(&m_hts, &simulated_meas);

        switch (err_code)
        {
            case NRF_SUCCESS:
                // Measurement was successfully sent, wait for confirmation.
                m_hts_meas_ind_conf_pending = true;
                break;

            case NRF_ERROR_INVALID_STATE:
                // Ignore error.
                break;

            default:
                APP_ERROR_HANDLER(err_code);
                break;
        }
    }
}


/**@brief Function for handling the Health Thermometer Service events.
 *
 * @details This function will be called for all Health Thermometer Service events which are passed
 *          to the application.
 *
 * @param[in] p_hts  Health Thermometer Service structure.
 * @param[in] p_evt  Event received from the Health Thermometer Service.
 */
static void on_hts_evt(ble_hts_t * p_hts, ble_hts_evt_t * p_evt)
{
    switch (p_evt->evt_type)
    {
        case BLE_HTS_EVT_INDICATION_ENABLED:
            // Indication has been enabled, send a single temperature measurement
            temperature_measurement_send();
            break;

        case BLE_HTS_EVT_INDICATION_CONFIRMED:
            m_hts_meas_ind_conf_pending = false;
            break;

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


/**@brief Function for handling Queued Write Module errors.
 *
 * @details A pointer to this function will be passed to each service which may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void nrf_qwr_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for initializing services that will be used by the application.
 *
 * @details Initialize the Health Thermometer, Battery and Device Information services.
 */
static void services_init(void)
{
    ret_code_t         err_code;
    ble_hts_init_t     hts_init;
    ble_bas_init_t     bas_init;
    ble_dis_init_t     dis_init;
    nrf_ble_qwr_init_t qwr_init = {0};
    ble_dis_sys_id_t   sys_id;

    // Initialize Queued Write Module.
    qwr_init.error_handler = nrf_qwr_error_handler;

    APP_ERROR_CHECK(nrf_ble_qwr_init(&m_qwr, &qwr_init));

    // Initialize Health Thermometer Service
    memset(&hts_init, 0, sizeof(hts_init));

    hts_init.evt_handler                 = on_hts_evt;
    hts_init.temp_type_as_characteristic = TEMP_TYPE_AS_CHARACTERISTIC;
    hts_init.temp_type                   = BLE_HTS_TEMP_TYPE_BODY;

    // Here the sec level for the Health Thermometer Service can be changed/increased.
    hts_init.ht_meas_cccd_wr_sec = SEC_JUST_WORKS;
    hts_init.ht_type_rd_sec      = SEC_OPEN;

    APP_ERROR_CHECK(ble_hts_init(&m_hts, &hts_init));

    // Initialize Battery Service.
    memset(&bas_init, 0, sizeof(bas_init));

    // Here the sec level for the Battery Service can be changed/increased.
    bas_init.bl_rd_sec        = SEC_OPEN;
    bas_init.bl_cccd_wr_sec   = SEC_OPEN;
    bas_init.bl_report_rd_sec = SEC_OPEN;

    bas_init.evt_handler          = NULL;
    bas_init.support_notification = true;
    bas_init.p_report_ref         = NULL;
    bas_init.initial_batt_level   = 100;

    APP_ERROR_CHECK(ble_bas_init(&m_bas, &bas_init));

    // Initialize Device Information Service.
    memset(&dis_init, 0, sizeof(dis_init));

    ble_srv_ascii_to_utf8(&dis_init.manufact_name_str, MANUFACTURER_NAME);
    ble_srv_ascii_to_utf8(&dis_init.model_num_str, MODEL_NUM);

    sys_id.manufacturer_id            = MANUFACTURER_ID;
    sys_id.organizationally_unique_id = ORG_UNIQUE_ID;
    dis_init.p_sys_id                 = &sys_id;

    dis_init.dis_char_rd_sec = SEC_OPEN;

    APP_ERROR_CHECK(ble_dis_init(&dis_init));
}


/**@brief Function for initializing the sensor simulators.
 */
static void sensor_simulator_init(void)
{
    m_battery_sim_cfg.min          = MIN_BATTERY_LEVEL;
    m_battery_sim_cfg.max          = MAX_BATTERY_LEVEL;
    m_battery_sim_cfg.incr         = BATTERY_LEVEL_INCREMENT;
    m_battery_sim_cfg.start_at_max = true;

    sensorsim_init(&m_battery_sim_state, &m_battery_sim_cfg);

    // Temperature is in celcius (it is multiplied by 100 to avoid floating point arithmetic).
    m_temp_celcius_sim_cfg.min          = MIN_CELCIUS_DEGREES;
    m_temp_celcius_sim_cfg.max          = MAX_CELCIUS_DEGRESS;
    m_temp_celcius_sim_cfg.incr         = CELCIUS_DEGREES_INCREMENT;
    m_temp_celcius_sim_cfg.start_at_max = false;

    sensorsim_init(&m_temp_celcius_sim_state, &m_temp_celcius_sim_cfg);
}


/**@brief Function for handling the Connection Parameters Module.
 *
 * @details This function will be called for all events in the Connection Parameters Module which
 *          are passed to the application.
 *          @note All this function does is to disconnect. This could have been done by simply
 *                setting the disconnect_on_fail config parameter, but instead we use the event
 *                handler mechanism to demonstrate its use.
 *
 * @param[in] p_evt  Event received from the Connection Parameters Module.
 */
static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
{
    if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
    {
        APP_ERROR_CHECK(sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE));
    }
}


/**@brief Function for handling a Connection Parameters error.
 *
 * @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)
{
    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             = false;
    cp_init.evt_handler                    = on_conn_params_evt;
    cp_init.error_handler                  = conn_params_error_handler;

    APP_ERROR_CHECK(ble_conn_params_init(&cp_init));
}


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

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

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


/**@brief Function for handling advertising events.
 *
 * @details This function will be 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)
{
    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            NRF_LOG_INFO("Fast advertising.");
            APP_ERROR_CHECK(bsp_indication_set(BSP_INDICATE_ADVERTISING));
            break;

        case BLE_ADV_EVT_IDLE:
            sleep_mode_enter();
            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)
{
    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Connected.");
            APP_ERROR_CHECK(bsp_indication_set(BSP_INDICATE_CONNECTED));
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
            APP_ERROR_CHECK(nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle));
            m_device_connected = true;
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected.");
            m_conn_handle               = BLE_CONN_HANDLE_INVALID;
            m_hts_meas_ind_conf_pending = false;
            m_device_connected          = false;
            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,
            };
            APP_ERROR_CHECK(sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys));
        } break;

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

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

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


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void)
{
    APP_ERROR_CHECK(nrf_sdh_enable_request());

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

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

    // 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 BSP module.
 *
 * @param[in]   event   Event generated by button press.
 */
static void bsp_event_handler(bsp_event_t event)
{
    ret_code_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 the Peer Manager initialization.
 */
static void peer_manager_init(void)
{
    ble_gap_sec_params_t sec_param;

    APP_ERROR_CHECK(pm_init());

    memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

    // Security parameters to be used for all security procedures.
    sec_param.bond           = SEC_PARAM_BOND;
    sec_param.mitm           = SEC_PARAM_MITM;
    sec_param.lesc           = SEC_PARAM_LESC;
    sec_param.keypress       = SEC_PARAM_KEYPRESS;
    sec_param.io_caps        = SEC_PARAM_IO_CAPABILITIES;
    sec_param.oob            = SEC_PARAM_OOB;
    sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
    sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
    sec_param.kdist_own.enc  = 1;
    sec_param.kdist_own.id   = 1;
    sec_param.kdist_peer.enc = 1;
    sec_param.kdist_peer.id  = 1;

    APP_ERROR_CHECK(pm_sec_params_set(&sec_param));

    APP_ERROR_CHECK(pm_register(pm_evt_handler));
}


/**@brief Clear bond information from persistent storage.
 */
static void delete_bonds(void)
{
    NRF_LOG_INFO("Erase bonds!");

    APP_ERROR_CHECK(pm_peers_delete());
}


/**@brief Function for initializing the Advertising functionality.
 *
 * @details Encodes the required advertising data and passes it to the stack.
 *          Also builds a structure to be passed to the stack when starting advertising.
 */
static void advertising_init(void)
{
    ble_advertising_init_t init;

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

    init.advdata.name_type               = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance      = true;
    init.advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
    init.advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.advdata.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;

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

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


/**@brief Function for initializing buttons and leds.
 *
 * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
 */
static void buttons_leds_init(bool * p_erase_bonds)
{
    bsp_event_t startup_event;

    APP_ERROR_CHECK(bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler));

    APP_ERROR_CHECK(bsp_btn_ble_init(NULL, &startup_event));

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


/**@brief Function for initializing the nrf log module.
 */
static void log_init(void)
{
    APP_ERROR_CHECK(NRF_LOG_INIT(NULL));

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing power management.
 */
static void power_management_init(void)
{
    APP_ERROR_CHECK(nrf_pwr_mgmt_init());
}


/**@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)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}


/**@brief Function for starting advertising.
 */
static void advertising_start(bool erase_bonds)
{
    if (erase_bonds == true)
    {
        delete_bonds();
        // Advertising is started by PM_EVT_PEERS_DELETE_SUCCEEDED event.
    }
    else
    {
        APP_ERROR_CHECK(ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST));
    }
}


/**@brief Function for application main entry.
 */
int main(void)
{
    bool erase_bonds;

    // Initialize.
    log_init();   
    timers_init();
    buttons_leds_init(&erase_bonds);  
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    advertising_init();
    services_init();
    sensor_simulator_init();
    conn_params_init();
    peer_manager_init();
    
    // Start execution.
    NRF_LOG_INFO("Health Thermometer example started.");
    advertising_start(erase_bonds);

    saadc_init();
    saadc_sampling_event_init();
    saadc_sampling_event_enable();
    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}


/**
 * @}
 */

0601.sdk_config.h

[Håkon Alseth]

Hi,

 

I am very sorry, I have misinformed you previously.

When you are enabling more than one channel, the SAADC enters scan mode, where it samples all enabled channels when you trigger the start task.

Due to this behavior in hardware, you are actually sampling both inputs at 5 ms interval.

 

Kind regards,

Håkon

[Duy]

Hello,

Thank you for your feedback. Now I understand. So all I need is only 1 PPI channel, is it right? It will trigger both SAADC channels too.

I also found the answer for similar question about multiple SAADCs at different intervals: https://devzone.nordicsemi.com/f/nordic-q-a/20214/multiple-saadc 

[Duy]

Hello Håkon Alseth,

One more question, which function or variable allows me to know that the sample belongs to SAADC channel 0, 1, 2...?

Thank you and best regards, 

            Duy