I'm using MQX 4.0 with Tower system (Kinetis K60).
I'm writing a task that communicates to another device through the serial port of TWR-SER board. I'm able to open the port and send/receive bytes on that port without problems.
Now I'd like to have a function similar to the classical select() function: I want to put the task in blocked state until a character on the serial port has arrived or a timeout expires. I noticed the select() function is implemented only in RTCS, but not for simple I/O serial port.
The serial protocol I'm implemented is master/slave, where the MQX application is the master. So it sends a packet and waits for the answer. The wait can't be indefinitely, because the other device couldn't be actually connected, so I have to do something if this condition occurs.
I can open the serial port in polling non-blocking mode and poll the serial port with fgetc() and make some ticks calculations to detect the timeout:
while(1) {
send_packet();
end = start = _time_ticks();
while(_time_diff(end, start) < TIMEOUT) {
c = fgetc(serial_port);
if (c >= 0) {
add_to_rx(c);
if (rxpacket_complete()) {
break;
}
}
if (rxpacket_complete()) {
/* Process the incoming packet */
clear_rx();
} else {
/* No answer */
}
}
But I'd like to avoid this. The task is always running and never goes in blocked mode.
