Usıng TWI with BLE nRF52dk

RE: Usıng TWI with BLE nRF52dk

Kenneth — Wed, 14 Apr 2021 19:32:39 GMT

Event type (decimal) 87 is 0x57, and if you look at ble_ranges.h you can find it's a BLE_GATTS_EVT_BASE event. If you open ble_gatts.h you can find all events that start from BLE_GATTS_EVT_BASE:

enum BLE_GATTS_EVTS
{
  BLE_GATTS_EVT_WRITE = BLE_GATTS_EVT_BASE,       /**< Write operation performed.                                           \n See @ref ble_gatts_evt_write_t.                 */
  BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST,             /**< Read/Write Authorization request.                                    \n Reply with @ref sd_ble_gatts_rw_authorize_reply. \n See @ref ble_gatts_evt_rw_authorize_request_t. */
  BLE_GATTS_EVT_SYS_ATTR_MISSING,                 /**< A persistent system attribute access is pending.                     \n Respond with @ref sd_ble_gatts_sys_attr_set.     \n See @ref ble_gatts_evt_sys_attr_missing_t.     */
  BLE_GATTS_EVT_HVC,                              /**< Handle Value Confirmation.                                           \n See @ref ble_gatts_evt_hvc_t.                   */
  BLE_GATTS_EVT_SC_CONFIRM,                       /**< Service Changed Confirmation.                                        \n No additional event structure applies.          */
  BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST,             /**< Exchange MTU Request.                                                \n Reply with @ref sd_ble_gatts_exchange_mtu_reply. \n See @ref ble_gatts_evt_exchange_mtu_request_t. */
  BLE_GATTS_EVT_TIMEOUT,                          /**< Peer failed to respond to an ATT request in time.                    \n See @ref ble_gatts_evt_timeout_t.               */
  BLE_GATTS_EVT_HVN_TX_COMPLETE                   /**< Handle Value Notification transmission complete.                     \n See @ref ble_gatts_evt_hvn_tx_complete_t.       */
};

This means 0x57 is BLE_GATTS_EVT_HVN_TX_COMPLETE, and the notification have been sent with success (yay!). I guess you need to look at the handle, data and length you tried to pass to sd_ble_gatts_hvx(), and why that was random?

Kenneth

RE: Usıng TWI with BLE nRF52dk

kefom — Wed, 14 Apr 2021 19:01:06 GMT

yes you were right the 104 was not an error code but it was the value of mpu who am i result so i just comment the part for

 //   err_code=readByte(MPU6050_ADDRESS, ADDRESS_WHO_AM_I);
 //   APP_ERROR_CHECK(err_code);

and i checked the results of who am i myself and they are both 104 so thecniquely I2C is working so thanks for that ( i still dont know why it gave error like it was fine when i was using thiss code for just TWI )i still have a problem with BLE tough it sends random data again i am fine with that i didnt give any init_value for that but i cant update it ( change the value as i wish) it gets stuck and says this on logger

<info> app: In ble_cus_custom_value_update. 

<info> app: sd_ble_gatts_hvx result: 0. 

<info> app: BLE event received. Event type = 87

do you have any suggestions about this without A logic analyzer because i dont own one and cant go anywhere because of the pandemic

Best regards

Efe

Sorry for taking this much of your time .

RE: Usıng TWI with BLE nRF52dk

Kenneth — Wed, 14 Apr 2021 16:21:28 GMT

So what code is executing on line 29 of mpu6050.c? Next step would be to find from the API description what the error code 104 may mean. However, I can find from mpu6050.c the following comment:

#define ADDRESS_WHO_AM_I (0x75U) // !< WHO_AM_I register identifies the device. Expected value is 0x68.

The value 0x68 is 104 (decimal), maybe this is not an error code.
A logic analyzer trace is very useful.

Kenneth

RE: Usıng TWI with BLE nRF52dk

kefom — Wed, 14 Apr 2021 11:13:43 GMT

i did added debug to my definitions and got

<error> app: ERROR 104 [Unknown error code] at C:\Users\HP\Desktop\nrf_sdk_17\nRF5_SDK_17.0.0_9d13099\examples\MY PROJECT\ble_app_Fall\Lib\mpu6050.c:29
PC at: 0x0002FF7D
<error> app: End of error report

RE: Usıng TWI with BLE nRF52dk

kefom — Tue, 13 Apr 2021 20:25:40 GMT

i tried debugging it but i cant see any error code its always 0x00 in the times that i can see but when it enters nrf libraries it just goes to nrf_breakpoint and i cant put a red dot ( break point) so i cant look whats going on

i can explain like this :

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();
    services_init();
    advertising_init();
    conn_params_init();
    peer_manager_init();

    // Start execution.
    NRF_LOG_INFO("setting done");
    application_timers_start();
    NRF_LOG_INFO("timers started");
    advertising_start(erase_bonds);

    I2C_init();
    NRF_LOG_INFO("I2C is done");
    mpu6050_init();
    NRF_LOG_INFO("mpu6050 is done");

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

it starts in main then enters

    mpu6050_init();

bool mpu6050_init(void)
{   
  bool transfer_succeeded = true;
	
  //Check the id to confirm that we are communicating with the right device
  transfer_succeeded &= mpu6050_verify_product_id();
	
  if(mpu6050_verify_product_id() == false)
    {
	return false;
      }

  // Set the registers with the required values, see the datasheet to get a good idea of these values
  (void)writeByte(MPU6050_ADDRESS, MPU_PWR_MGMT1_REG , 0x00); 
  (void)writeByte(MPU6050_ADDRESS, MPU_SAMPLE_RATE_REG , 0x07); 
  (void)writeByte(MPU6050_ADDRESS, MPU_CFG_REG , 0x06); 						
  (void)writeByte(MPU6050_ADDRESS, MPU_INT_EN_REG, 0x00); 
  (void)writeByte(MPU6050_ADDRESS, MPU_GYRO_CFG_REG , 0x18); 
  (void)writeByte(MPU6050_ADDRESS, MPU_ACCEL_CFG_REG,0x00);   		

  return transfer_succeeded;
}

from here it enters

  transfer_succeeded &= mpu6050_verify_product_id();
  
  // which is
  
  
  bool mpu6050_verify_product_id(void)
{
    uint8_t who_am_i; // create a variable to hold the who am i value
    ret_code_t err_code;
    
    // Note: All the register addresses including WHO_AM_I are declared in 
    // MPU6050.h file, you can check these addresses and values from the
    // datasheet of your slave device.
    err_code=readByte(MPU6050_ADDRESS, ADDRESS_WHO_AM_I);
    APP_ERROR_CHECK(err_code);

    who_am_i= readByte(MPU6050_ADDRESS, ADDRESS_WHO_AM_I);

        if (who_am_i != MPU6050_WHO_AM_I)
        {
            return false;
        }
        else
        {
            return true;
        }

}

in this function it goes to

    who_am_i= readByte(MPU6050_ADDRESS, ADDRESS_WHO_AM_I);
    
    
    

uint8_t readByte(uint8_t address, uint8_t subAddress)
{
    ret_code_t err_code = 0;
    
    uint8_t value;
    
    m_xfer_done = false;
 
    err_code = nrf_drv_twi_tx(&i2c, address, &subAddress, 1, true);

    APP_ERROR_CHECK(err_code);
    
    while (m_xfer_done == false); //wait until end of transfer
    
    if (err_code == NRF_SUCCESS)
    {
        m_xfer_done = false;
       
        err_code = nrf_drv_twi_rx(&i2c, address, &value, 1);
        APP_ERROR_CHECK(err_code);
        
        while (m_xfer_done == false);
    };

    return value;
}

from here

    err_code = nrf_drv_twi_tx(&i2c, address, &subAddress, 1, true);


// here the err_code is 0x00


ret_code_t nrf_drv_twi_tx(nrf_drv_twi_t const * p_instance,
                          uint8_t               address,
                          uint8_t const *       p_data,
                          uint8_t               length,
                          bool                  no_stop)
{
    ret_code_t result = 0;
    if (NRF_DRV_TWI_USE_TWIM)
    {
        result = nrfx_twim_tx(&p_instance->u.twim,
                                address, p_data, length, no_stop);
    }
    else if (NRF_DRV_TWI_USE_TWI)
    {
        result = nrfx_twi_tx(&p_instance->u.twi,
                               address, p_data, length, no_stop);
    }
    return result;
}

nrfx_err_t nrfx_twim_tx(nrfx_twim_t const * p_instance,
                        uint8_t             address,
                        uint8_t     const * p_data,
                        size_t              length,
                        bool                no_stop)
{
    nrfx_twim_xfer_desc_t xfer = NRFX_TWIM_XFER_DESC_TX(address, (uint8_t*)p_data, length);

    return nrfx_twim_xfer(p_instance, &xfer, no_stop ? NRFX_TWIM_FLAG_TX_NO_STOP : 0);
}

// from this line 

 nrfx_twim_xfer_desc_t xfer = NRFX_TWIM_XFER_DESC_TX(address, (uint8_t*)p_data, length);
 
 // i cant follow the code and i dont want to change the code and risk it should i risk it and add err_code here ?

and after this it goes to nrf_breakpoint_cond or just enters a part in disassembly and stay there and does nothing

i know i couldnt make myself clear enough sorry about that i am new in this line of work

Best regards and many thanks

Efe

RE: Usıng TWI with BLE nRF52dk

Kenneth — Tue, 13 Apr 2021 10:14:45 GMT

What is the error code returned from nrfx_twim_tx() in this case?

Kenneth

RE: Usıng TWI with BLE nRF52dk

kefom — Mon, 12 Apr 2021 21:45:30 GMT

i tried debugging but unfortunately i cant go furter from this code it breaks down from here and goes does nothing and sometimes it just goes to nrf_breakpoint and wants to reset itself i followed this

 nrfx_twim_xfer_desc_t xfer = NRFX_TWIM_XFER_DESC_TX(address, (uint8_t*)p_data, length);

this function is normal sdk code and now i dont know how to fix this

nrfx_err_t nrfx_twim_tx(nrfx_twim_t const * p_instance,
                        uint8_t             address,
                        uint8_t     const * p_data,
                        size_t              length,
                        bool                no_stop)
{
    nrfx_twim_xfer_desc_t xfer = NRFX_TWIM_XFER_DESC_TX(address, (uint8_t*)p_data, length);

    return nrfx_twim_xfer(p_instance, &xfer, no_stop ? NRFX_TWIM_FLAG_TX_NO_STOP : 0);
}

RE: Usıng TWI with BLE nRF52dk

Kenneth — Mon, 12 Apr 2021 11:42:26 GMT

You might want to build with Debug instead of Release, then you may find if the code is asserting:
https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/an-introduction-to-error-handling-in-nrf5-projects

Then you can set a breakpoint in app_error_fault_handler() to find the exact error code and file number and file name the error occurs.

Kenneth