UART baudrate change gives non-intuitive result

[kaolpr]

In my application I need to first send some bytes using one baudrate and then, using the same UART, switch to another. I used the following code:

Code: Select all

uart_config_t uart_config = {
        .baud_rate = 250000,
        .data_bits = UART_DATA_8_BITS,
        .parity    = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_2,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE
};
uart_param_config(UART_NUM_2, &uart_config);
uart_set_pin(UART_NUM_2, ECHO_TEST_TXD, ECHO_TEST_RXD, ECHO_TEST_RTS, ECHO_TEST_CTS);
uart_driver_install(UART_NUM_2, 2048, 0, 0, NULL, 0); // Expecting blocking TX calls as TX buffer is set to 0

uint8_t buffer[] = { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE}; // First byte will be sent using lower baudrate

while(1) {
	// The slow part
        uart_set_baudrate(UART_NUM_2, 50000));
        uart_write_bytes(UART_NUM_2, (const char *) buffer, 1);
        // uart_wait_tx_done(UART_NUM_2, 1000 / portTICK_PERIOD_MS);   <- also tried with this one, though with 0 TX buffer it seems to be pointless
        
        // The fast part
        uart_set_baudrate(UART_NUM_2, 200000));
        uart_write_bytes(UART_NUM_2, (const char *) buffer, 5);        
}

Well, it seems that something is wrong here (I'm a newbie to this platform) as both bytes are in fact sent with the letter baudrate (200000). Could you please direct me what can be wrong here?