132 lines
4.4 KiB
C
132 lines
4.4 KiB
C
/* This file demonstrates the interaction between two processes via events.
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*
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* - "Sensor process": Throws an event periodically. This can be for example a
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* sensor value.
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* - "Print process" : Waits for events from "Sensor" and prints a message when
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* an event occurs (e.g. prints the sensor value)
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*
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* This example is derived from the contiki code examples for the WSN430
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* (SensTools - Inria: http://senstools.gforge.inria.fr/)
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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 <limits.h>
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#include <stdio.h> /* For printf() */
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#include "event-post.h"
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/* This is our event type */
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static process_event_t event_data_ready;
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/*---------------------------------------------------------------------------*/
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/* Declare the two processes here */
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PROCESS(sensor_process, "Sensor process");
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PROCESS(print_process, "Print process");
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/* Tell Contiki that we want them to start automatically */
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AUTOSTART_PROCESSES(&sensor_process, &print_process);
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/*---------------------------------------------------------------------------*/
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/* Implementation "Sensor Process" */
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PROCESS_THREAD(sensor_process, ev, data)
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{
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/* static variables to preserve values across consecutive calls of this
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* process. */
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/* Set an etimer */
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static struct etimer timer;
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/* And the 'sensor' monitoring variable */
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static struct event_struct es;
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PROCESS_BEGIN();
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/* Set some near-the-limit initial values */
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/* signed primitives */
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es.s_val = SHRT_MAX-2;
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es.i_val = INT_MAX-2;
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es.l_val = LONG_MAX-2;
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/* sizeof(long long) == sizeof(long) on sensinodes - see other examples*/
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es.ll_val = LONG_MAX-2;
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/* and some typedef-ed unsigned variables */
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es.u8_val = UCHAR_MAX-2;
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es.u16_val = USHRT_MAX-2;
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es.u32_val = ULONG_MAX-2;
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/* allocate the required event */
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event_data_ready = process_alloc_event();
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/* process_event_t is actually a u_char. What did the OS allocate for us? */
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printf("Contiki allocated event ID %d.\r\n", event_data_ready);
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/* Set a timer here. We will generate an event every times this timer expires
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* etimer_set accepts clock ticks as its 2nd argument.
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* CLOCK_CONF_SECOND is the number of ticks per second.
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* This CLOCK_CONF_SECOND * N = N seconds */
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etimer_set(&timer, CLOCK_CONF_SECOND * 2);
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while (1)
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{
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printf("Sensor process: Wait for timer event...\r\n");
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/* Wait on our timer */
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PROCESS_WAIT_EVENT_UNTIL(ev == PROCESS_EVENT_TIMER);
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/* blip */
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/* leds_toggle(LEDS_BLUE); */
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/* Set the 'sensor' value before throwing the event */
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printf("Sensor Process: Incrementing values...\r\n");
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es.s_val++;
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es.i_val++;
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es.l_val++;
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es.ll_val++;
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es.u8_val++;
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es.u16_val++;
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es.u32_val++;
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/* Post our event.
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* N.B. es is declared static.
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* Try passing a volatile variable and observe the results... */
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printf("Sensor Process: Generating 'Data Ready' event.\r\n");
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process_post(&print_process, event_data_ready, &es);
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/* reset the timer so we can wait on it again */
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etimer_reset(&timer);
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}
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PROCESS_END();
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}
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/*---------------------------------------------------------------------------*/
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/* Implementation of "Print Process" */
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PROCESS_THREAD(print_process, ev, data)
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{
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struct event_struct * sd;
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PROCESS_BEGIN();
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while (1)
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{
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/* Stop here and wait until "event_data_ready" occurs */
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PROCESS_WAIT_EVENT_UNTIL(ev == event_data_ready);
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/* When the event occurs, the incoming data will be stored in
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* process_data_t data (careful, this is void *)
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*
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* Print away...
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* es is volatile, we need to set it = data again and dereference it. */
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sd = data;
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printf("Print Process - Data Ready:\r\n");
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printf(" s: %d\r\n", sd->s_val);
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printf(" i: %d\r\n", sd->i_val);
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printf(" l: %ld\r\n", sd->l_val);
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printf(" ll: %lld\r\n", sd->ll_val);
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printf(" u8: %u\r\n", sd->u8_val);
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printf(" u16: %u\r\n", sd->u16_val);
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printf(" u32: %lu\r\n", sd->u32_val);
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/* aaaaand back to waiting for the next event */
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}
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PROCESS_END();
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}
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/*---------------------------------------------------------------------------*/
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