Contiki/Cooja How to read data (in a simulated mote) from socket (serial socket (server/client))

Question

I'm trying to build a MQTT-SN with a MQTT-Rime gateway. I succeed to send sensor data to the gateway with a serial socket but my gateway have to send some data too to the motes. My problem is that I don't know how to read data from the socket in a mote. Someone can help me?

Answer 1

If the input data is newline-terminated ASCII, you can use the serial line interface.

 #include "contiki.h"
 #include "dev/serial-line.h"
 #include <stdio.h>

 PROCESS(test_serial, "Serial line test process");
 AUTOSTART_PROCESSES(&test_serial);

 PROCESS_THREAD(test_serial, ev, data)
 {
   PROCESS_BEGIN();

   for(;;) {
     PROCESS_YIELD();
     if(ev == serial_line_event_message) {
       printf("received line: %s\n", (char *)data);
     }
   }
   PROCESS_END();
 }

If the data is binary, you need define your own callback function:

int binary_input_byte(unsigned char c) {
   // ...
}

Then set this as the serial interface callback (using uart0 here, the exact name you need to use is platform-dependent):

uart0_set_input(binary_input_byte);