HomeEnergyMeter/main/toshiba_ir.c

#include "toshiba_ir.h"
#include <stdint.h>
#include <stdio.h>
#include "esp_log.h"
#include "rxTimer.h"

enum
{
    UNKNOWN,
    T0,
    T1,
    T2,
    T3,
    TEMP1_OK,
    DONE
};

static uint8_t rx_state = UNKNOWN;

static uint64_t sensor_data;
static uint32_t rx_numBits;


void Toshiba_ir_ResetDecoder()
{
    sensor_data = 0;
    rx_numBits = 0;
    rx_state = UNKNOWN;
}

static void addBit(uint8_t value)
{

    rx_numBits++;
    sensor_data = (sensor_data << 1) + (value & 0x01);

    rx_state = TEMP1_OK;
}

#define START_PULSE_MIN (3880-200)
#define START_PULSE_MAX (4010+200)

#define T0_PULSE_MIN (380-100)
#define T0_PULSE_MAX (520+100)

#define SHORT_PULSE_MIN (890-100)
#define SHORT_PULSE_MAX (990+100)

#define LONG_PULSE_MIN (1880-150)
#define LONG_PULSE_MAX (1980+150)


static int32_t rx_decode(uint32_t width)
{
    switch (rx_state) {
        case UNKNOWN: // Start of frame
            if ( START_PULSE_MIN <= width && width <= START_PULSE_MAX )
            {
                rx_state = T0;
            }
            else
            {
                return -1; // error, reset
            }
            break;

        case T0: // First half of pulse : HIGH around 230us

            if (rx_numBits == 32)
            { // end of frame
                rx_state = DONE;
                sensor_data = (sensor_data >> 8); // Mask away some bits at the end
                return 1;
            }
            else if( T0_PULSE_MIN <= width && width <= T0_PULSE_MAX )
            {
                rx_state = T1;
            }
            else
            {
                if (rx_numBits == 0 && START_PULSE_MIN <= width && width <= START_PULSE_MAX )
                {
                    rx_state = T0;
                }
                else
                {
                    return -1; // error, reset
                }
            }
            break;

        case T1:
            if( SHORT_PULSE_MIN <= width && width <= SHORT_PULSE_MAX )
            {
                addBit(0);
            }
            else if( LONG_PULSE_MIN <= width && width <= LONG_PULSE_MAX )
            {
                addBit(1);
            }
            else
            {
                return -1; // error, reset
            }
            rx_state = T0;
            break;
    }
    return 0;
}

int64_t nextPulseToshiba_ir(uint32_t width)
{
    static int64_t previous_data = 0;
    static uint32_t old_time=0;
    static uint32_t now;
    int64_t retVal = -1;

    if (width > 0)
    {
        if (rx_state != DONE)
        {
            switch (rx_decode(width))
            {
            case -1:
                Toshiba_ir_ResetDecoder();
                break;
            case 1:
                rx_state = DONE;
                break;
            }
        }
    }
    if (rx_state == DONE) {
        now = millis();

        if( sensor_data != previous_data || (now > (old_time+1000)) ) {
            previous_data = sensor_data;
            retVal = sensor_data;
            
        }
        old_time = now;
        Toshiba_ir_ResetDecoder();
    }
    
    return retVal;
}