Ian Wolf
/
TEMPFINALInterrupt
Interrupt with character limit
Fork of Temperature_Reading1 by
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?
User | Revision | Line number | New 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 | } |