Reducing libuarte power consumption getting ERROR 3735928559

[jerome.sc]

Hello,

I've been using the libuarte module in my project, and I done a power consumption reading. With libuarte switched on I'm consuming 0.78ma, and with it switched off is in the uA range. This means I need to turn it off when not in use and back on, when I need it.

Essentially I'm intialising/uninitialising the UART based on interrupts. When testing the code I'm getting the error message:

ERROR 3735928559 [Unknown error code] at C:\Users\yyy\Documents\yyy\yyy\nRF5_SDK_17.1.0_ddde560\modules\nrfx\drivers\src\nrfx_gpiote.c:473
PC at: 0x00020ABB

/**@brief  Function for initializing the UART module.
 */
/**@snippet [UART Initialization] */
static void uart_init(void) {
  uint32_t err_code;

  nrf_libuarte_async_config_t nrf_libuarte_async_config = {
      .tx_pin = TX_PIN_NUMBER,
      .rx_pin = RX_PIN_NUMBER,
      .baudrate = NRF_UARTE_BAUDRATE_57600,
      .parity = NRF_UARTE_PARITY_EXCLUDED,
      .hwfc = NRF_UARTE_HWFC_DISABLED,
      .timeout_us = 200,
      .int_prio = APP_IRQ_PRIORITY_LOW};

  err_code = nrf_libuarte_async_init(&libuarte, &nrf_libuarte_async_config, uart_event_handler, (void *)&libuarte);
  APP_ERROR_CHECK(err_code);

  nrf_libuarte_async_enable(&libuarte);
}

volatile static bool uart_en_flag = false;

void ble_pdn_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action) {
  NRF_LOG_PROCESS();
  ret_code_t err_code;
  
  if (uart_en_flag)
  NRF_LOG_INFO("Disabling UART");
  uart_en_flag = false;
  nrf_libuarte_async_uninit(&libuarte);
}

void ble_wakeup_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action) {
  NRF_LOG_PROCESS();
    ret_code_t err_code;


  adv_serv_data[1] = 0xAA;
  adv_data_update(adv_serv_data);

  if (!uart_en_flag)
  {
    NRF_LOG_INFO("Enabling UART");
      err_code = nrf_drv_gpiote_init();
  APP_ERROR_CHECK(err_code);

      nrf_libuarte_async_config_t nrf_libuarte_async_config = {
      .tx_pin = TX_PIN_NUMBER,
      .rx_pin = RX_PIN_NUMBER,
      .baudrate = NRF_UARTE_BAUDRATE_57600,
      .parity = NRF_UARTE_PARITY_EXCLUDED,
      .hwfc = NRF_UARTE_HWFC_DISABLED,
      .timeout_us = 200,
      .int_prio = APP_IRQ_PRIORITY_LOW};

  err_code = nrf_libuarte_async_init(&libuarte, &nrf_libuarte_async_config, uart_event_handler, (void *)&libuarte);
  APP_ERROR_CHECK(err_code);

  nrf_libuarte_async_enable(&libuarte);

  }

}

/**
 * @brief Function for configuring two interrupt pins, and one output.
 */
static void gpio_init(void) {
  ret_code_t err_code;

  err_code = nrf_drv_gpiote_init();
  APP_ERROR_CHECK(err_code);

  /* Initialse LED as an output */
  nrf_gpio_cfg_output(LED_1);
  nrf_gpio_pin_set(LED_2);

  nrf_drv_gpiote_in_config_t in_config = GPIOTE_CONFIG_IN_SENSE_HITOLO(true);
  in_config.pull = NRF_GPIO_PIN_PULLUP;

  err_code = nrf_drv_gpiote_in_init(BUTTON_1, &in_config, ble_pdn_handler);
  APP_ERROR_CHECK(err_code);

  nrf_drv_gpiote_in_event_enable(BUTTON_1, true);

  err_code = nrf_drv_gpiote_in_init(BUTTON_2, &in_config, ble_wakeup_handler);
  APP_ERROR_CHECK(err_code);

  nrf_drv_gpiote_in_event_enable(BUTTON_2, true);
}

Calling nrf_libuarte_async_uninit(&libuarte) seems to work fine, but when trying to reinitialise the libuarte I'm getting the error above. It looks like from the error it has something to do with gpiote. Am I doing the process of of turning on/off the uart periperhal wrong?

[jerome.sc]

Call stack looks like in the image below. Looks like it's failing at: NRFX_ASSERT(pin_in_use_by_te(pin));

I haven't tried moving it out the interrupt, but will give it a go.

[jerome.sc]

Ok, I've tried removing the initialising outside the interrupt handler to the main and I still get the same problem. Not sure what I'm doing wrong, but most implementations I've tried is always failing on NRFX_ASSERT(pin_in_use_by_te(pin));

[Jørgen Holmefjord]

Hi,

nrf_libuarte_async_init() fails because the pin config for rts_pin is not specified in the config structure, and is therefore set to 0x00. Since you set NRF_UARTE_HWFC_DISABLED, the pin will not configured using GPIOTE, and the driver will not recognize the pin as initialized by the GPIOTE driver. By coincidence, the first init will succeed, as the rts_pin is set to 0x00, and the check of pin_assignments in pin_in_use_by_te will succeed as the GPIOTE driver is not initialized at this point (where pin_assignments will be set to all 0xFF, before init it is all 0x00). When you do the second init/re-init, the GPIOTE driver have been initialized, and the check will fail.

You should be able to resolve this issue by including this in the config:

.rts_pin = NRF_UARTE_PSEL_DISCONNECTED,

I will report this internally, as it is a potential bug.

Best regards,
Jørgen

[Tirth_S]

Jørgen Holmefjord said:

NRF_UARTE_HWFC_DISABLED