Function esp_idf_sys::uart_read_bytes

pub unsafe extern "C" fn uart_read_bytes(
    uart_num: uart_port_t,
    buf: *mut c_void,
    length: u32,
    ticks_to_wait: TickType_t
) -> c_int

@brief UART read bytes from UART buffer

@param uart_num UART port number, the max port number is (UART_NUM_MAX -1). @param buf pointer to the buffer. @param length data length @param ticks_to_wait sTimeout, count in RTOS ticks

@return - (-1) Error - OTHERS (>=0) The number of bytes read from UART buffer