Hi,
Working with Vidar Berg hx711 library and want to add some function for taring. I have a problem that when i run my simple taring function, the function returns 0, but it should not, because only thing that it should do is making average from samples comming from hx711 and then return the result. Please see attached code.
Thanks in advance
working with nRF52832, SDK15.2., ble_app_uart_w_hx711 from Vidar, SES
Pepam
#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 "nrf_ble_qwr.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_pwr_mgmt.h"
#include "hx711.h"
#include "nrf_delay.h"
#if defined (UART_PRESENT)
#include "nrf_uart.h"
#endif
#if defined (UARTE_PRESENT)
#include "nrf_uarte.h"
#endif
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#define APP_BLE_CONN_CFG_TAG 1 /**< A tag identifying the SoftDevice BLE configuration. */
#define DEVICE_NAME "Nordic_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 event (connect or start of notification) to 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. */
int hx711_imme;
long calib_val;
BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT); /**< BLE NUS service instance. */
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 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}
};
/**@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 analyse
* 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] 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);
}
/**@brief Function for the GAP initialization.
*
* @details This function will set 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 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 handling the data from the Nordic UART Service.
*
* @details This function will process the data received from the Nordic UART BLE Service and send
* it to the UART module.
*
* @param[in] p_evt Nordic UART Service event.
*/
/**@snippet [Handling the data received over BLE] */
static void nus_data_handler(ble_nus_evt_t * p_evt)
{
if (p_evt->type == BLE_NUS_EVT_RX_DATA)
{
//TODO:Process commands from Central
}
}
/**@snippet [Handling the data received over BLE] */
/**@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;
nrf_ble_qwr_init_t qwr_init = {0};
// Initialize Queued Write Module.
qwr_init.error_handler = nrf_qwr_error_handler;
err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
APP_ERROR_CHECK(err_code);
// Initialize NUS.
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 an event from 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)
{
uint32_t err_code;
if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
{
err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
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 = false;
cp_init.evt_handler = on_conn_params_evt;
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 will 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 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)
{
uint32_t err_code;
switch (ble_adv_evt)
{
case BLE_ADV_EVT_FAST:
err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
APP_ERROR_CHECK(err_code);
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)
{
uint32_t err_code;
switch (p_ble_evt->header.evt_id)
{
case BLE_GAP_EVT_CONNECTED:
NRF_LOG_INFO("Connected");
err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
APP_ERROR_CHECK(err_code);
m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
APP_ERROR_CHECK(err_code);
break;
case BLE_GAP_EVT_DISCONNECTED:
NRF_LOG_INFO("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_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;
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, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
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
*this function is used to compute offset for taring a scale. In this code it is used to write computed offset to global variable "calib_val"
*which is then readed by NRF_LOG_INFO().
* @param[in] uint8_t times
*/
long HX711_tare(uint8_t times) // function must be called after hx711_init()
{
long offset;
for(int i; i<times; i++)
{
hx711_start(true);
nrf_delay_ms(50);
offset += (long)hx711_imme;
hx711_stop();
}
offset /= times;
return offset;
}
void hx711_callback(hx711_evt_t evt, int value)
{
uint16_t length = sizeof(int);
hx711_imme = value; // makes copy of "value" to global variable "hx711_imme"
if(evt == DATA_READY)
{
/* Transmit received sensor data over BLE - ignoring return value. Packets will be dropped
if:
- Not connected
- Client has not enabled Notification on the TX characteristic
- TX buffer is full*/
(void)ble_nus_data_send(&m_nus, (uint8_t *) &value, &length, m_conn_handle);
//NRF_LOG_INFO("ADC measuremement %d", value);
}
else
{
/*Invalid ADC readout. A non-zero value would indicate that the readout was interrupted
by a higher priority interrupt during readout (i.e., Softdevice radio event).
*/
NRF_LOG_INFO("ADC readout error. %d 0x%x", value, value);
}
}
/**@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.
*
* @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;
uint32_t err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
APP_ERROR_CHECK(err_code);
err_code = bsp_btn_ble_init(NULL, &startup_event);
APP_ERROR_CHECK(err_code);
*p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}
/**@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 initializing power management.
*/
static void power_management_init(void)
{
ret_code_t err_code;
err_code = nrf_pwr_mgmt_init();
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());
nrf_pwr_mgmt_run();
}
/**@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 Application main function.
*/
int main(void)
{
bool erase_bonds;
// Initialize.
hx711_init(INPUT_CH_A_128, hx711_callback);
log_init();
timers_init();
buttons_leds_init(&erase_bonds);
calib_val = HX711_tare(5);
power_management_init();
ble_stack_init();
gap_params_init();
gatt_init();
services_init();
advertising_init();
conn_params_init();
// Start execution.
NRF_LOG_INFO("calib_val: %d", calib_val);
NRF_LOG_INFO("Debug logging for UART over RTT started.");
// advertising_start();
/* Start continous sampling. Sampling rate is either
10Hz or 80 Hz, depending on hx711 HW configuration*/
//hx711_start(false);
// Enter main loop.
for (;;)
{
idle_state_handle();
}
}
