ESP32 Forum

Hi! I'm trying to figure out if there is a way to get current transmit status of UART driver?

I found a function in the HAL that fully matches my question:
But it use only in block waiting for the transmission ends and internal ISR routine. May be there are some macros or any other API I missed? Is there a way to use it without breaking library hierarchy and jumping to HAL from my code?

Also I can't understand using of this API - FIFO space threshold or transmission timeout reached:
I can configurate this interrupts, but no functions to use this interrupts or callbacks for it. How work with it? In case when I don't register a custom lower level interrupt handler using Thanks in advance, Michael.

You might be able to call with ticks_to_wait = 0, and check the return value.
If it returns ESP_ERR_TIMEOUT, then you know a transmission is happening.

For example

fevang wrote: You might be able to call

Code: Select all

/**
 * @brief Wait until UART TX FIFO is empty.
 *
 * @param uart_num      UART port number, the max port number is (UART_NUM_MAX -1).
 * @param ticks_to_wait Timeout, count in RTOS ticks
 *
 * @return
 *     - ESP_OK   Success
 *     - ESP_FAIL Parameter error
 *     - ESP_ERR_TIMEOUT  Timeout
 */
esp_err_t uart_wait_tx_done(uart_port_t uart_num, TickType_t ticks_to_wait);

with ticks_to_wait = 0, and check the return value.
If it returns ESP_ERR_TIMEOUT, then you know a transmission is happening.

Thank you for your reply! I missed such a simple opportunity to solve my problem with transmit status.

But the second part of my question (FIFO space threshold API) is still not clear...