HomeEnergyMeter/main/Sensors/oregon.c

#include "oregon.h"
#include <stdint.h>
#include <stdio.h>
#include "../rxTimer.h"
#include <string.h>
#include "esp_log.h"
#include "config.h"

#ifdef TRANCEIVER_ENABLED

static void done ();

static unsigned char total_bits, bits, flip, state, pos, data[25];
char result_str[25];

enum { UNKNOWN, T0, T1, T2, T3, SENSOR_OK, DONE };

void Oregon_ResetDecoder () {
    total_bits = bits = pos = flip = 0;
    state = UNKNOWN;
    memset(result_str,'\0',sizeof(result_str));
}


// V3-Version of the gitBit-function
static void gotBit (char value) {
    data[pos] = (data[pos] >> 1) | (value ? 0x80 : 00);
    total_bits++;
    pos = total_bits >> 3;
    if (pos >= sizeof data) {
        Oregon_ResetDecoder();
        return;
    }
    state = SENSOR_OK;
}

// store a bit using Manchester encoding
static void manchester (char value) {
    flip ^= value; // manchester code, long pulse flips the bit
    gotBit(flip);
}

static void done () {
    while (bits)
        gotBit(0); // padding
    state = DONE;
}

static int rx_decode( int width ) {
    if( (480-200) < width && width < (980+200) ) {
        char w = width >= 730;
        switch (state) {
            case UNKNOWN:
                if (w == 0)
                    ++flip;
                else if (32 <= flip) {
                    flip = 1;
                    manchester(1);  // Width 950
                } else
                    return -1;
                break;
            case SENSOR_OK:
                if (w == 0)
                    state = T0;
                else 
                    manchester(1);  // Width 980

                break;
            case T0:
                if (w == 0)
                    manchester(0);  // Width 480
                else
                    return -1;
                break;
        }
    } else {
        return -1;
    }
    return  total_bits == 80 ? 1: 0;
}

 //10 bytes data: 2A 19 04 CE 00 00 60 12 00 30

char * nextPulseOregonSensor(uint32_t width) {
    if( state != DONE ) {
    
        switch (rx_decode(width)) {
            case -1:
                Oregon_ResetDecoder();
                break;
            case 1:
                done();
                break;
        }
    }
    if( state == DONE ) {
        if( pos == 10 ) {
            for( int i=0; i<pos; i++ ) {
                sprintf(result_str+(i*2),"%02X",data[i] );
            }

            return result_str;
        }
        else {
            Oregon_ResetDecoder();
            return  (char *)NULL;
        }
    }
    else 
        return (char *)NULL;
}

#endif