Unicast example in Contiki

Simple unicast example, Click button in each node to unicast message.

Please consider that this code is written for cooja simulator.

UniA.c for node 1

#include "contiki.h"
#include "net/rime.h"
#include "dev/button-sensor.h"
#include "dev/leds.h"
#include <stdio.h>

PROCESS(example_unicast_process, "Example unicast");
AUTOSTART_PROCESSES(&example_unicast_process);

static void
recv_uc(struct unicast_conn *c, const rimeaddr_t *from)
{
  printf("broadcast message received from %d.%d: '%s'\n",from->u8[0], from->u8[1], (char *)packetbuf_dataptr());
}

static const struct unicast_callbacks unicast_callbacks = {recv_uc};

static struct unicast_conn uc;

static void unicast_message()
{
    unicast_open(&uc, 146, &unicast_callbacks);

    rimeaddr_t addr;
    
    packetbuf_copyfrom("AAAAA", 5);
    addr.u8[0] = 2;
    addr.u8[1] = 0;
    if(!rimeaddr_cmp(&addr, &rimeaddr_node_addr))
    {
      unicast_send(&uc, &addr);
    }
}

PROCESS_THREAD(example_unicast_process, ev, data)
{
  PROCESS_EXITHANDLER(unicast_close(&uc);)
    
  PROCESS_BEGIN();
  
  while(1) {
    PROCESS_WAIT_EVENT_UNTIL(ev == sensors_event && data == &button_sensor);
    unicast_message();
    printf("message sent.\n");
  }  
    
  PROCESS_END();
}

UniB.c for node2

#include "contiki.h"
#include "net/rime.h"
#include "dev/button-sensor.h"
#include "dev/leds.h"
#include <stdio.h>

PROCESS(example_unicast_process, "Example unicast");
AUTOSTART_PROCESSES(&example_unicast_process);

static void
recv_uc(struct unicast_conn *c, const rimeaddr_t *from)
{
  printf("broadcast message received from %d.%d: '%s'\n",from->u8[0], from->u8[1], (char *)packetbuf_dataptr());
}

static const struct unicast_callbacks unicast_callbacks = {recv_uc};

static struct unicast_conn uc;

static void unicast_message()
{
    unicast_open(&uc, 146, &unicast_callbacks);

    rimeaddr_t addr;
    
    packetbuf_copyfrom("BBBBB", 5);
    addr.u8[0] = 1;
    addr.u8[1] = 0;
    if(!rimeaddr_cmp(&addr, &rimeaddr_node_addr))
    {
      unicast_send(&uc, &addr);
    }
}

PROCESS_THREAD(example_unicast_process, ev, data)
{
  PROCESS_EXITHANDLER(unicast_close(&uc);)
    
  PROCESS_BEGIN();
  
  while(1) {
    PROCESS_WAIT_EVENT_UNTIL(ev == sensors_event && data == &button_sensor);
    unicast_message();
    printf("message sent.\n");
  }  
    
  PROCESS_END();
}