int_temp_sensor.c

/* See license.txt for license information. */
#include "mywisp.h"
#if (ACTIVE_SENSOR == SENSOR_INTERNAL_TEMP)

#include "dlwisp41.h"
#include "rfid.h"
#include "int_temp_sensor.h"

unsigned char sensor_busy = 0;

void init_sensor()
{
  return;
}

void read_sensor(unsigned char volatile *target) 
{
  
#if MONITOR_DEBUG_ON
  // for monitor - set READ_SENSOR_STATE debug line - 00101 - 5
  P1OUT |= wisp_debug_1;
  P1OUT &= ~wisp_debug_1;
  P2OUT &= ~wisp_debug_2;
  P3OUT = 0x21;
#endif
  
  // slow down clock
  BCSCTL1 = XT2OFF + RSEL1; // select internal resistor (still has effect when DCOR=1)
  DCOCTL = DCO1+DCO0; // set DCO step. 
  
  if(!is_power_good())
    sleep();
  
  // already off. Only needs to be done when READ has set
  P1OUT &= ~RX_EN_PIN;   // turn off comparator
  
  // Set up ADC for internal temperature sensor  
  ADC10CTL0 &= ~ENC; // make sure this is off otherwise settings are locked.
  ADC10CTL1 = INCH_10 + ADC10DIV_3;         // Temp Sensor ADC10CLK/4
  ADC10CTL0 = SREF_1 + ADC10SHT_3 + REFON + ADC10ON;
  
  // a little time for regulator to stabilize active mode current AND
  // filter caps to settle.
  for (int i = 0; i < 50; i++);
  
  // start conversion
  unsigned int k = 0;
  ADC10CTL0 |= ENC + ADC10SC;             // Sampling and conversion start
  
  while (ADC10CTL1 & ADC10BUSY);    // wait while ADC finished work
  
  *(target + k + 1 ) = (ADC10MEM & 0xff);
  // grab msb bits and store it
  *(target + k) = (ADC10MEM & 0x0300) >> 8;
  
  // Power off sensor and adc
  ADC10CTL0 &= ~ENC;
  ADC10CTL1 = 0;       // turn adc off
  ADC10CTL0 = 0;       // turn adc off
  
  
  // Store sensor read count
  sensor_counter++;
  ackReply[10] = (sensor_counter & 0x00ff);
  // grab msb bits and store it
  ackReply[9]  = (sensor_counter & 0xff00) >> 8;
  
  return;
}

unsigned char is_sensor_sampling()
{
  if ( sensor_busy ) return 1;
  return 0;
}

#endif // (ACTIVE_SENSOR == SENSOR_INTERNAL_TEMP)