Ian Wolf / Mbed 2 deprecated TEMPFINALInterrupt

Interrupt with character limit

Dependencies:   mbed

Fork of Temperature_Reading1 by jack kemnitz

main.cpp@2:d9fa8ce1b14e, 2017-08-31 (annotated)

Committer:
iwolf32
Date:
Thu Aug 31 14:08:54 2017 +0000
Revision:
2:d9fa8ce1b14e
Parent:
1:1de97b1145f3 
Temp Interrupt with limit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
212600191 0:1f9fae46bbe1 1 #include "mbed.h"
212600191 1:1de97b1145f3 2
212600191 1:1de97b1145f3 3 // Read temperature from MAX1363 3-channel ADC
212600191 1:1de97b1145f3 4
212600191 1:1de97b1145f3 5 I2C i2c(PB_9 , PB_8);
iwolf32 2:d9fa8ce1b14e 6 DigitalOut Relay(D7);
iwolf32 2:d9fa8ce1b14e 7 Serial pc(SERIAL_TX, SERIAL_RX);
212600191 1:1de97b1145f3 8
iwolf32 2:d9fa8ce1b14e 9 char buffer[]={'0','0','0','0','0','\0'};
iwolf32 2:d9fa8ce1b14e 10 char ch;
iwolf32 2:d9fa8ce1b14e 11 double SetTemp=0;
iwolf32 2:d9fa8ce1b14e 12 float x=0;
212600191 1:1de97b1145f3 13
212600191 1:1de97b1145f3 14 // address information for the Serenity temperature sensor device
212600191 1:1de97b1145f3 15 const int SLAVE_ADDRESS = 0x34 << 1;
212600191 1:1de97b1145f3 16
212600191 1:1de97b1145f3 17 // MAX1363 registers
212600191 1:1de97b1145f3 18 const unsigned char MAX1363_CONFIG_REG = 0x03; // single-ended inputs, read CH0-CH1 only
212600191 1:1de97b1145f3 19 const unsigned char MAX1363_SETUP_REG = 0xF2; // AIN3=output, INT REF always on
212600191 1:1de97b1145f3 20
212600191 1:1de97b1145f3 21 // MAX1363 high byte format (byte 2 is D7-D0)
212600191 1:1de97b1145f3 22 const unsigned char MAX1363_VALID_MASK = 0x90; // HIGH bit and 12/10 bit should always be 1
212600191 1:1de97b1145f3 23 const unsigned char MAX1363_HIGH_DATA_MASK = 0x0F;
212600191 1:1de97b1145f3 24
212600191 1:1de97b1145f3 25 // channel address (0-3) is in CH1/CH0 (bits 5/6)
212600191 1:1de97b1145f3 26 const unsigned char MAX1363_CHANNEL_MASK = 0x60;
212600191 1:1de97b1145f3 27 const unsigned char MAX1363_CHANNEL_SHIFT = 5;
212600191 0:1f9fae46bbe1 28
212600191 1:1de97b1145f3 29 /** conversion factors */
212600191 1:1de97b1145f3 30 const float CONV_COEFF_A3 = 4.39403;
212600191 1:1de97b1145f3 31 const float CONV_COEFF_A2 = -11.15;
212600191 1:1de97b1145f3 32 const float CONV_COEFF_A1 = 36.4955;
212600191 1:1de97b1145f3 33 const float CONV_COEFF_A0 = 266.909;
212600191 1:1de97b1145f3 34
212600191 1:1de97b1145f3 35 const int CONV_N = 12;
212600191 1:1de97b1145f3 36 const float CONV_VREF = 2.048;
212600191 1:1de97b1145f3 37
212600191 1:1de97b1145f3 38 const float CONV_K_TO_C = -272.15;
212600191 0:1f9fae46bbe1 39
212600191 1:1de97b1145f3 40 float AdcToC(unsigned int _adc)
212600191 1:1de97b1145f3 41 {
212600191 1:1de97b1145f3 42 float d = CONV_VREF * _adc / (1L << CONV_N);
212600191 1:1de97b1145f3 43 float d2 = d*d;
212600191 1:1de97b1145f3 44 float d3 = d2*d;
212600191 1:1de97b1145f3 45 float temp_k = (CONV_COEFF_A3 * d3) +
212600191 1:1de97b1145f3 46 (CONV_COEFF_A2 * d2) +
212600191 1:1de97b1145f3 47 (CONV_COEFF_A1 * d) +
212600191 1:1de97b1145f3 48 CONV_COEFF_A0;
212600191 1:1de97b1145f3 49 return temp_k + CONV_K_TO_C;
212600191 1:1de97b1145f3 50 }
212600191 0:1f9fae46bbe1 51
iwolf32 2:d9fa8ce1b14e 52 void callback(){
iwolf32 2:d9fa8ce1b14e 53 if (pc.readable()==1){
iwolf32 2:d9fa8ce1b14e 54 for (int index=0; index<5; index=index+1){
iwolf32 2:d9fa8ce1b14e 55 ch=pc.getc();
iwolf32 2:d9fa8ce1b14e 56 buffer[index]=ch;
iwolf32 2:d9fa8ce1b14e 57 }
iwolf32 2:d9fa8ce1b14e 58 SetTemp= atof(buffer);
iwolf32 2:d9fa8ce1b14e 59 return;
iwolf32 2:d9fa8ce1b14e 60 }
iwolf32 2:d9fa8ce1b14e 61 }
iwolf32 2:d9fa8ce1b14e 62
212600191 0:1f9fae46bbe1 63 int main() {
iwolf32 2:d9fa8ce1b14e 64 pc.baud(115200);
iwolf32 2:d9fa8ce1b14e 65
iwolf32 2:d9fa8ce1b14e 66 pc.attach(&callback);
212600191 1:1de97b1145f3 67
212600191 1:1de97b1145f3 68 // reserve 4 bytes for transfer
212600191 1:1de97b1145f3 69 char cmd[4];
212600191 1:1de97b1145f3 70
212600191 1:1de97b1145f3 71 // initialize the adc device
212600191 1:1de97b1145f3 72 cmd[0] = MAX1363_CONFIG_REG;
212600191 1:1de97b1145f3 73 cmd[1] = MAX1363_SETUP_REG;
212600191 1:1de97b1145f3 74 i2c.write(SLAVE_ADDRESS, cmd, 2);
212600191 1:1de97b1145f3 75
212600191 1:1de97b1145f3 76 // holds raw adc values as we convert them
212600191 1:1de97b1145f3 77 unsigned int adc[2] = {0};
212600191 1:1de97b1145f3 78 float values[2] = {0};
212600191 1:1de97b1145f3 79
212600191 0:1f9fae46bbe1 80 while (1) {
iwolf32 2:d9fa8ce1b14e 81 wait(0.1);
212600191 1:1de97b1145f3 82
212600191 1:1de97b1145f3 83 // clear buffer, only to detect invalid data
212600191 0:1f9fae46bbe1 84 cmd[0] = 0x00;
212600191 1:1de97b1145f3 85 cmd[1] = 0x00;
212600191 1:1de97b1145f3 86 cmd[2] = 0x00;
212600191 1:1de97b1145f3 87 cmd[3] = 0x00;
212600191 1:1de97b1145f3 88
212600191 1:1de97b1145f3 89 // read 4 bytes from
212600191 1:1de97b1145f3 90 i2c.read(SLAVE_ADDRESS, cmd, 4);
212600191 1:1de97b1145f3 91
212600191 1:1de97b1145f3 92 for (int i=0; i<4; i+=2) {
212600191 1:1de97b1145f3 93 // first 4 bits contain expected bits and channel id
212600191 1:1de97b1145f3 94 if ((cmd[i] & MAX1363_VALID_MASK) == MAX1363_VALID_MASK) {
212600191 1:1de97b1145f3 95 unsigned char ch = ((cmd[i] & MAX1363_CHANNEL_MASK) >> MAX1363_CHANNEL_SHIFT);
212600191 1:1de97b1145f3 96 adc[ch] = ((int)(cmd[i] & MAX1363_HIGH_DATA_MASK) << 8) | cmd[i+1];
212600191 1:1de97b1145f3 97 values[ch] = AdcToC(adc[ch]);
212600191 1:1de97b1145f3 98 } else {
212600191 1:1de97b1145f3 99 // handle invalid data
212600191 1:1de97b1145f3 100 }
212600191 1:1de97b1145f3 101 }
iwolf32 2:d9fa8ce1b14e 102 x=values[1];
iwolf32 2:d9fa8ce1b14e 103 if (x<SetTemp){
iwolf32 2:d9fa8ce1b14e 104 Relay=0;
iwolf32 2:d9fa8ce1b14e 105 }
iwolf32 2:d9fa8ce1b14e 106 if (x>SetTemp+1){
iwolf32 2:d9fa8ce1b14e 107 Relay=1;
iwolf32 2:d9fa8ce1b14e 108 }
212600191 1:1de97b1145f3 109 // output temperature data
iwolf32 2:d9fa8ce1b14e 110 printf("%0.2f\t %0.2f\t %0.2f\r\n", SetTemp, values[0], values[1]);
iwolf32 2:d9fa8ce1b14e 111
212600191 0:1f9fae46bbe1 112 }
212600191 1:1de97b1145f3 113 }