In SDK14.2, for nrf52832, TWI can't write data with sd_app_evt_wait() in mainly loop, but when comment it, read/write all ok

[xjmnn]

Hello, boss, I used twi read/write data from others device, I find a strange problem, When in no-blocking mode, mainly loop use "sd_app_evt_wait" TWI can't write data to others device or not correctly ,But read is ok, When comment "sd_app_evt_wait", read/write is all okey, I just use "nrf_drv_twi_tx" and "nrf_drv_twi_xfer" function, and callback event function. have anyone meet this problem, expect for reply! 

[Simon]

I will try to provide an answer by upcoming monday/tuesday. Could you upload your code or a snippet of it?

Simon

[xjmnn]

Those is many code in the project, Work diagram as following, 

1. Initialize TWI and ble, 

2. startup TWI polling every 100ms

3. If uart Wirte command comes , sometimes write some data to TWI slave

4. Then continue read

TWI code:

//TWI event callback:

void twi_handler(nrf_drv_twi_evt_t const * p_event, void * p_context)
{
ptcmdContxt ctx = (ptcmdContxt)p_context;
switch (p_event->type)
{
case NRF_DRV_TWI_EVT_DONE:
if (( p_event->xfer_desc.type == NRF_DRV_TWI_XFER_RX )||( NRF_DRV_TWI_XFER_TXRX ==p_event->xfer_desc.type ))
{
....//process data and context
}
else if ( NRF_DRV_TWI_XFER_TX == p_event->xfer_desc.type )
{
....//process data and context
}
break;
default:
break;
}
}

//TWI read

int restatrtTxRx ( nrf_drv_twi_t const * twi, uint8_t addr, uint8_t* p_tx_data, uint8_t tlen, uint8_t* p_rx_data, uint8_t rlen)
{
nrf_drv_twi_xfer_desc_t xfer = NRF_DRV_TWI_XFER_DESC_TXRX( addr, p_tx_data, tlen, p_rx_data, rlen );
uint32_t flags = NRF_DRV_TWI_FLAG_RX_POSTINC|
NRF_DRV_TWI_FLAG_TX_NO_STOP;
ret_code_t ret = nrf_drv_twi_xfer(twi, &xfer, flags);
return ret;
}

////TWI write
int my_write_register(uint8_t addr, //!< Target IC's SMBus address
uint8_t command_code, //!< Command Code to be written to
uint16_t data, //!< Data to be written
nrf_drv_twi_t const * p_instance //!< Pointer to port instance struct
)
{
ret_code_t err_code;
uint8_t val[3];//,buf[2];

val[0] = command_code; val[1] = data&0x00ff; val[2] = (data>>8)&0x00ff; //val[3] = 0x0;//from the low byte to high high

err_code = nrf_drv_twi_tx( p_instance, addr, val, sizeof(val), false);

APP_ERROR_CHECK(err_code);
return err_code;
}

//TWI read

int my_read_register(uint8_t addr, //!< Target IC's SMBus address
uint8_t command_code, //!< Command Code to be read from
uint16_t *data, //!< Pointer to data destination
nrf_drv_twi_t const * p_instance //!< Pointer to port configuration struct
)
{
ret_code_t err_code;
uint8_t txdata = command_code;

err_code = restatrtTxRx ( p_instance, addr, &txdata, sizeof(uint8_t), (uint8_t*) data, sizeof(uint16_t) );
//err_code = nrf_drv_twi_rx( p_instance, addr, (uint8_t*)data, sizeof(data));

APP_ERROR_CHECK(err_code);
//NRF_LOG_INFO("\tRaw read fake data: %d\n",*data);
return err_code;
}

Main code:

int main(void)
{
uint32_t err_code;
bool erase_bonds;

err_code = app_timer_init();
APP_ERROR_CHECK(err_code);

log_init();

myTwiInit();
myUartInit();

buttons_leds_init(&erase_bonds);
ble_stack_init();

//peer_manager_init(); //xjmnn for buttonless dfu init

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


err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
APP_ERROR_CHECK(err_code);

for (;;)
{
UNUSED_RETURN_VALUE(NRF_LOG_PROCESS());//process log information
//power_manage();//When uncomment this, TWI write is not right
dispatchTwiData();
dispatchUartData();
}
}

 

[Simon]

Have you tried to debug your project? Try setting a break point in your twi_handler() function to check if it's called. Do you call NRF_LOG_FLUSH() in the twi_handler()? As mentioned here, it will cause problems. 

However I was able to merge the BLE Blinky Application with the TWI Sensor Example with the BLE and TWI functionality both working. I have attached the example.

ble_app_blinky_template_twi_sensor.zip

Best regards, 

Simon

[xjmnn]

Thks first, I have test " BLE Blinky Application and TWI Sensor Example ",It's no problem , Now in my Project , I just used TWI process SMbus data, from battery, Maybe some times is different between SMbus and TWI, ?

[Simon]

What is your frequency? As mentioned in this link, if you are using SMBus the speed should not exceed 100 kHz.