92 lines
3.2 KiB
C
92 lines
3.2 KiB
C
/* This is a very simple hello_world program.
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* It aims to demonstrate the co-existence of two processes:
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* One of them prints a hello world message and the other blinks the LEDs
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*
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* It is largely based on hello_world in $(CONTIKI)/examples/sensinode
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*
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* Author: George Oikonomou <G.Oikonomou@lboro.ac.uk>
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*/
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#include "contiki.h"
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#include "dev/leds.h"
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#include <stdio.h> /* For printf() */
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/*---------------------------------------------------------------------------*/
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/* We declare the two processes */
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PROCESS(hello_world_process, "Hello world process");
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PROCESS(blink_process, "LED blink process");
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/* We require the processes to be started automatically */
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AUTOSTART_PROCESSES(&hello_world_process, &blink_process);
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/*---------------------------------------------------------------------------*/
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/* Implementation of the first process */
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PROCESS_THREAD(hello_world_process, ev, data)
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{
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/* variables are declared static to ensure their values are maintained
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between subsequent calls.
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All the code between PROCESS_THREAD and PROCESS_BEGIN() runs each time
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the process is invoked. */
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static struct etimer timer;
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static int count;
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/* any process must start with this. */
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PROCESS_BEGIN();
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/* set the etimer module to generate an event in one second.
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CLOCK_CONF_SECOND is #define as 128 */
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etimer_set(&timer, CLOCK_CONF_SECOND * 4);
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count = 0;
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/* Don't declare variables after PROCESS_BEGIN.
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* While it will compile fine with TARGET=native (gcc is happy),
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* SDCC doesn't like it. Soon as you try TARGET=sensinode you will get:
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* syntax error: token -> 'int' ;
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* Try uncommenting the line below and observe the results */
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/* int whoops = 0;
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* whoops = 0; */
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while (1)
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{
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/* wait here for an event to happen */
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PROCESS_WAIT_EVENT();
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/* This achieves the same
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* PROCESS_WAIT_EVENT_UNTIL(ev == PROCESS_EVENT_TIMER); */
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/* if the event is the timer event as expected... */
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if(ev == PROCESS_EVENT_TIMER)
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{
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/* do the process work */
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printf("Sensor says no... #%d\r\n", count);
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count ++;
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/* reset the timer so it will generate an other event
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* the exact same time after it expired (periodicity guaranteed) */
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etimer_reset(&timer);
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}
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/* and loop */
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}
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/* any process must end with this, even if it is never reached. */
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PROCESS_END();
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}
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/*---------------------------------------------------------------------------*/
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/* Implementation of the second process */
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PROCESS_THREAD(blink_process, ev, data)
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{
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static struct etimer timer;
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PROCESS_BEGIN();
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while (1)
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{
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/* we set the timer from here every time */
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etimer_set(&timer, CLOCK_CONF_SECOND);
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/* and wait until the event we receive is the one we're waiting for */
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PROCESS_WAIT_EVENT_UNTIL(ev == PROCESS_EVENT_TIMER);
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printf("Blink... (state %0.2X).\r\n", leds_get());
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/* update the LEDs */
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leds_toggle(LEDS_GREEN);
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}
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PROCESS_END();
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}
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/*---------------------------------------------------------------------------*/
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