HomeWizardRec.cpp

/*
 * Listener for 433MHz "HomeWizard" signals (on a Raspi).
 * Created as https://github.com/1technophile/NewRemoteSwitch did not work for me.
 * License: GPLv3.
 * 
 *         _   _
 * '0':   | |_| |_____ (T,T,T,5T)
 *         _       _
 * '1':   | |_____| |_	(T,5T,T,T)
 * 
 * - start pulse: 1T high, 10T low
 * - 26 bit:  Address
 * - 1  bit:  group bit
 * - 1  bit:  on/off/[dim]
 * - 4  bit:  unit
 * - stop pulse: 1T high, 40T low
 * 
 * /

#include <wiringPi.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

const int PIN = 2;


static unsigned int nReceivedValue; // decoded val

/* //debug:
const int DUR_BUF_SIZE = 64;
static unsigned int DUR_BUF[DUR_BUF_SIZE];
static unsigned int DUR_BUF_POINT = 0;*/

void handleInterrupt() {
	static unsigned long lastTime = 0;
	static unsigned int recvBuff = 0;
	static unsigned char state = 0;

	static unsigned int pulse_len_short_max;
	static unsigned int pulse_len_long_max;
	static unsigned int pulse_len_sync_max;

	const long time = micros();
	const unsigned int duration = time - lastTime;

	if (duration < 100) return; //jitter

	if (1==digitalRead(PIN))
	{
		//rising -> delay is signal

		if (duration < pulse_len_short_max) {
			if (state==1)
			{
				state='0';//this was the fist pause of '0'
			}else if (state=='1')
			{
				recvBuff = (recvBuff << 1) | 1;
				state=1;//this was the second pause of '1'
			}else state=0;
		}else if (duration < pulse_len_long_max) {
			if (state==1)
			{
				state='1';//this was the fist pause of '1'
			}else if (state=='0')
			{
				recvBuff = recvBuff << 1;
				state=1;//this was the second pause of '0'
			}else state=0;
		}else if (duration < pulse_len_sync_max) {
			//sync
			state=1;
			//DUR_BUF_POINT = 0;
			recvBuff = 0;
		}else {
			//longer than everything
			if (state==1)
			{
				//also we had something in the past -> this must be the end
				nReceivedValue = recvBuff;
			}
			state = 0;
		}

		/*if (state==1 || DUR_BUF_POINT > 0)
		{
			DUR_BUF[DUR_BUF_POINT++] = state;
			if (DUR_BUF_POINT >= DUR_BUF_SIZE) {
				DUR_BUF_POINT = 0;
			}
		}*/

	}else{
		//falling -> delay is sync (HIGH is alway of duration T)
		if (240 < duration && duration < 280)
		{
			unsigned int pulseD = duration;

			pulse_len_short_max = pulseD * 3;
			pulse_len_long_max = pulseD * 7.5;
			pulse_len_sync_max = pulseD * 12;
		}
	}


	lastTime = time;  
}


int main(int argc, char *argv[]) {

	// This pin is not the first pin on the RPi GPIO header!
	// Consult https://projects.drogon.net/raspberry-pi/wiringpi/pins/
	// for more information.

	if(wiringPiSetup() == -1) {
	printf("wiringPiSetup failed, exiting...");
	return 0;
	}

	// Receiver on interrupt 0 => that is pin #2
	nReceivedValue = 0;
	wiringPiISR(PIN, INT_EDGE_BOTH, &handleInterrupt);


	while(1) {

		if (nReceivedValue != 0) {


			printf("%u\n", nReceivedValue );

			/*
			for(int i=0;i<DUR_BUF_SIZE;i++)
			{
				printf("%i\t", DUR_BUF[i] );
			}
			printf("\n");
			nReceivedValue = 0;
			for(int i=1;i<DUR_BUF_SIZE;i+=2)
			{
				nReceivedValue = nReceivedValue << 1;
				if (DUR_BUF[i]==49)
				 nReceivedValue |= 1;
				printf("%i", DUR_BUF[i]-48 );
			}
			printf("\n%u\n", nReceivedValue );*/

			fflush(stdout);
			nReceivedValue = 0;
		}
		usleep(100); 

	}

	exit(0);


}