nRF52 bug

RE: nRF52 bug

Nur2705 — Mon, 05 Jul 2021 11:36:52 GMT

thank you very much for answering in detail

RE: nRF52 bug

Dmitry — Mon, 05 Jul 2021 08:22:58 GMT

When you're using an event handler in nrf_drv_twi_init(), TWI driver works in async mode - nrf_drv_twi_tx() returns immediately, transaction continues at background. There are two consequences to make your code stable:

1) you should wait for transaction to finish before sending a next one. If you're using a flag that is set in event handler by NRF_DRV_TWI_EVT_DONE event, don't forget to define that flag with volatile keyword.

2) automatic variable should not be used for tx buffer, because its content will likely be destroyed before transaction is finished. Define your buffer as static uint8_t buff[2].

RE: nRF52 bug

Nur2705 — Mon, 05 Jul 2021 07:31:08 GMT

   /**
 * @brief TWI events handler.
 */
void twi_handler(nrf_drv_twi_evt_t const * p_event, void * p_context)
{
    switch (p_event->type)
    {
        case NRF_DRV_TWI_EVT_DONE:
            m_xfer_done = true;
            break;
        default:
            break;
    }
}
/**
 * @brief TWI initialization.
 */
void twi_init (void)
{
    ret_code_t err_code;

    const nrf_drv_twi_config_t twi_lm75b_config = {
       .scl                = 27,
       .sda                = 26,
       .frequency          = NRF_DRV_TWI_FREQ_400K,
       .interrupt_priority = APP_IRQ_PRIORITY_HIGH,
       .clear_bus_init     = false
    };

    err_code = nrf_drv_twi_init(&m_twi, &twi_lm75b_config, twi_handler, NULL);
            NRF_LOG_INFO("\r\n nrf_drv_init = %d",err_code);
    NRF_LOG_FLUSH();
    APP_ERROR_CHECK(err_code);

    nrf_drv_twi_enable(&m_twi);
}

RE: nRF52 bug

Dmitry — Fri, 02 Jul 2021 09:58:52 GMT

Nursultan, could you show your TWI initialization code (nrf_drv_twi_init)? Are you using any event_handler?

RE: nRF52 bug

Nur2705 — Fri, 02 Jul 2021 08:03:07 GMT

Hello
I rebuilt the whole project and now it works
What was the reason, I never figured out

RE: nRF52 bug

Vidar Berg — Thu, 01 Jul 2021 12:54:06 GMT

Hello,

Could you please include the file (main.c maybe?) where these functions are being called as well? I would like to see your TWI initialization.

Also, please add error checking like Jared suggested your other ticket. This makes it much easier to catch errors.

err_code = nrf_drv_twi_tx(&m_twi, slave_addr, reg, 1, false);
APP_ERROR_CHECK(err_code); // Check if error_code == NRF_SUCCESS before continuing