Voorbeeld code van een bewegingsdetectie voor demonstratie van Home Automation met de Raspberry Pi

motion.c

#include <signal.h>
#include <stdio.h>
#include <wiringPi.h>

#define LED     4
#define PIR     5

volatile char isRunning = 1;

void processMotionDetection();
static void interruptHandler(const int signal);


int main() {
        // registreer interrupt signaal met de bijbehorende handler
        signal(SIGINT, interruptHandler);

        // doe een setup om wiringPi te gebruiken
        if(wiringPiSetup()<0) {
                printf("Error setting up wiringPi...");
                return -1;
        }

        // configureer de gewenste pinnen
        pinMode( LED, OUTPUT );
        pinMode( PIR, INPUT  );

        printf("Pin 4 is configured as output\n");
        printf("Pin 5 is configured as input\n");

        while(isRunning) {
                // 1. check for motion
                delay(100);
                if(digitalRead(PIR)) {
                        processMotionDetection();
                }
        }

        digitalWrite(LED, LOW);
        pinMode(LED, INPUT);

        printf("\nProgram finished... thank you :)\n");

        return 0;
}

void processMotionDetection() {
        printf("Motion detected!\n");
        printf("LED turned on!\n");

        digitalWrite(LED, HIGH);
        int timeout = 6;
        int motion = HIGH;
        while( motion || timeout ) {
                motion = digitalRead(PIR);
                if(motion)
                        timeout = 6;
                else
                        timeout--;
                delay(1000);
        }
        digitalWrite(LED, LOW);

        printf("LED turned off!\n");
}

static void interruptHandler(const int signal) {
        isRunning = 0;
}


/*
pi@raspberrypi:~/development/C $ gpio -v
 gpio version: 2.46
 Copyright (c) 2012-2018 Gordon Henderson
 This is free software with ABSOLUTELY NO WARRANTY.
 For details type: gpio -warranty

 Raspberry Pi Details:
  Type: Model B, Revision: 02, Memory: 512MB, Maker: Sony
  * Device tree is enabled.
  *--> Raspberry Pi Model B Rev 2
  * This Raspberry Pi supports user-level GPIO access.


pi@raspberrypi:~/development/C $ gpio readall
 +-----+-----+---------+------+---+-Model B1-+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5v      |     |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 1 | ALT0 | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | ALT0 | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 0 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 0 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 0 | IN   | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+-Model B1-+---+------+---------+-----+-----+
*/