Application firmware hangs up in twi_wait() function

[Andreas]

Hello

I`m using the NORDIC nrf_drv_twi driver implementation from the PACK environment (version equivalent to SDK 8.1.0). Together with the S120 softdevice. If there is an active ble connection, somtimes the firmware hangs up in the twi_wait() function.

void twi_wait(void){
	do
	{
			__WFE();
	}while(m_xfer_done == false);}

Is there any known issue about priority problems or something like this, that could cause such a behaviour? The twi driver runs on APP_IRQ_PRIORITY_HIGH. If I set this priority to APP_IRQ_PRIORITY_LOW, the twi implementation completly wont work, if there is an active BLE connection. So I try to read out some data from the device via ble. This doesn`t even work, if the priority is set to LOW. If the priority is set to HIGH, it works, but sometimes the firmware hangs up in the twi_wait function. Any ideas?

Regards, BTprogrammer

[Andreas]

Hello Kenneth, I changed my TWI driver initialisation and set the event handler to NULL. Now the application does not hang up any more. But I still get error 1 (NRF_ERROR_SVC_HANDLER_MISSING) sometimes from the nrf_drv_twi_tx() function call. How to go on with that? I think this breaks down my BLE data transmission... BR

[Kenneth]

I am not sure what is the problem here, but I can't find that nrf_drv_twi_tx() can return NRF_ERROR_SVC_HANDLER_MISSING error code. I searched for NRF_ERROR_SVC_HANDLER_MISSING in the twi source code in nRF5 SDK v11 - \examples\peripheral\twi_master_using_app_twi.

[Andreas]

Hello Kenneth, interesting, I can confirm, that I do not get the error if I slow down the function which causes very much I2C transfers per second in background. My EEPROM_write() function where I get the error looks like this:

res = nrf_drv_twi_tx(&m_twi_eeprom, EEPROM_HW_ADDR, m_address, 2, true);
if(res==NRF_SUCCESS){
...
}
else
{
dbg_printf("Error transmitting I2C read address %d!\r", res);
return NRF_DRV_TWI_ERROR;
}

and the output I get on the terminal looks like this: Error transmitting I2C read address 1! So for me it is clear that I get the error value 1 from nrf_drv_twi_tx()

[Kenneth]

You should modify:

  //bool res;
  ret_code_t res; 

Then most likely you will see it return the correct error code, but I am not sure why the compiler doesn't return a warning when it cast an uint32_t to bool.

[Andreas]

Hello Kenneth, sorry for that mistake. Of course, res will be one every time if it is bool... I changed it to ret_code_t. Now I get NRF_ERROR_BUSY, as return value from nrf_drv_twi_tx(). Is it a possible solution to only wait and try the transfer again? BR