wifigateway/Src/temp2.c

// Temperature sensor/hydrometer ProoveSmart TSS320 (Kjells)
#include "app.h"
#include "nexa.h"
#include "temp2.h"

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

static unsigned char temp2state = T0;

       unsigned long long temp2_x_data;
static unsigned int temp2x_numBits;

void temp2ResetDecoder () {
	temp2_x_data = 0;
	temp2x_numBits = 0;
	temp2state = T0;
}

static boolean temp2isDone() { return temp2state == DONE; }

static void temp2done () { temp2state = DONE; }

static void temp2gotBit (char value) {

	// X
	temp2x_numBits++;
	temp2_x_data = (temp2_x_data << 1) + (value & 0x01);

	temp2state = OK;
}


// Pulse timings
#define START_PULSE     860
#define LONG_PULSE     1380
#define SHORT_PULSE     480
#define MARG            100

static int temp2decode (unsigned int width) {
  
        
	switch (temp2state) {

	case T0: // First half of pulse : HIGH around 910

          if( temp2x_numBits == 48 ) {	// end of frame
                        temp2state = DONE;
			return 1;
		}
                else if ( (START_PULSE-MARG) <= width && width <= (START_PULSE+MARG) ) {
			temp2state = T1;
		}
		else {
                    return -1;	// error, reset
                }
		break;

	case T1:
                if ( (SHORT_PULSE-MARG) <= width && width <= (SHORT_PULSE+MARG)) {            // 410
			temp2gotBit(1);
		} else if ( (LONG_PULSE-MARG) <= width && width <= (LONG_PULSE+MARG) ) {          // 1290
			temp2gotBit(0);
		} else  {
                  return -1;	// error, reset
                }
		temp2state = T0;
		break;
	}
	return 0;
}

#pragma optimize=none
boolean nextPulseTemp2 (unsigned int width) {
  
  static int result;
  
  if( width > 0 ) {
    
    if( temp2state != DONE ) {
      
      result = temp2decode(width);

      switch( result ) {
	case -1:
          temp2ResetDecoder();
          break;
	case 1:
          temp2done();
          break;
        default:
        case 0:
          break;
      }
    }
  }
  
  return temp2isDone();
}