Hugo Harming / Mbed 2 deprecated Lots_of_DS18B20

// Demo on how to identify and read multiple DS18B20 connected to the same bus. // Parasitic power is not used in this example. // This program is based on the sample code from Maxim/Dallas application // note 162 (http://www.maxim-ic.com/app-notes/index.mvp/id/162). Program output should look like this: *** Test with multiple DS18B20 *** Memory allocated for 20 devices. Scanning for devices... ROM CODE =62:00:00:01:CB:25:CA:28 1 ROM CODE =B6:00:00:01:CB:1B:9E:28 2 ROM CODE =66:00:00:01:CB:28:59:28 3 3 devices found. Scanning completed. Temp: 022.6875 Device: 000001CB25CA 001 Temp: 022.6875 Device: 000001CB1B9E 002 Temp: 027.6250 Device: 000001CB2859 003 Temp: 022.6250 Device: 000001CB25CA 001 Temp: 022.6875 Device: 000001CB1B9E 002 Temp: 025.3125 Device: 000001CB2859 003 Temp: 022.8125 Device: 000001CB25CA 001 Temp: 024.1875 Device: 000001CB1B9E 002 Temp: 023.7500 Device: 000001CB2859 003

Dependencies:   mbed

main.cpp@7:cf5affdab535, 2016-01-28 (annotated)

Committer:
RRacer
Date:
Thu Jan 28 09:21:44 2016 +0000
Revision:
7:cf5affdab535
Parent:
4:6ade7fcb2925 
.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
RRacer 0:770734d973b0 1 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 2 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 3 // Lots_of_DS18B20
RRacer 0:770734d973b0 4 // Demo on how to identify and read multiple DS18B20 connected to the same bus.
RRacer 0:770734d973b0 5 // Parasitic power is not used in this example.
RRacer 0:770734d973b0 6 // This program is based on the sample code from Maxim/Dallas application
RRacer 0:770734d973b0 7 // note 162 (http://www.maxim-ic.com/app-notes/index.mvp/id/162).
RRacer 0:770734d973b0 8 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 9 //////////////////////////////////////////////////////////////////////////////
RRacer 4:6ade7fcb2925 10 // Program output should look like this:
RRacer 4:6ade7fcb2925 11 // *** Test with multiple DS18B20 ***
RRacer 4:6ade7fcb2925 12 // Memory allocated for 20 devices.
RRacer 4:6ade7fcb2925 13 // Scanning for devices...
RRacer 4:6ade7fcb2925 14 // ROM CODE =62:00:00:01:CB:25:CA:28 1
RRacer 4:6ade7fcb2925 15 // ROM CODE =B6:00:00:01:CB:1B:9E:28 2
RRacer 4:6ade7fcb2925 16 // ROM CODE =66:00:00:01:CB:28:59:28 3
RRacer 7:cf5affdab535 17 // 3 devices found.
RRacer 7:cf5affdab535 18 // Scanning completed.
RRacer 4:6ade7fcb2925 19 // Temp: 022.6875 Device: 000001CB25CA 001
RRacer 4:6ade7fcb2925 20 // Temp: 022.6875 Device: 000001CB1B9E 002
RRacer 4:6ade7fcb2925 21 // Temp: 027.6250 Device: 000001CB2859 003
RRacer 4:6ade7fcb2925 22 // Temp: 022.6250 Device: 000001CB25CA 001
RRacer 4:6ade7fcb2925 23 // Temp: 022.6875 Device: 000001CB1B9E 002
RRacer 4:6ade7fcb2925 24 // Temp: 025.3125 Device: 000001CB2859 003
RRacer 4:6ade7fcb2925 25 // Temp: 022.8125 Device: 000001CB25CA 001
RRacer 4:6ade7fcb2925 26 // Temp: 024.1875 Device: 000001CB1B9E 002
RRacer 4:6ade7fcb2925 27 // Temp: 023.7500 Device: 000001CB2859 003
RRacer 4:6ade7fcb2925 28 //////////////////////////////////////////////////////////////////////////////
RRacer 4:6ade7fcb2925 29 //////////////////////////////////////////////////////////////////////////////
RRacer 4:6ade7fcb2925 30 // I have found that adding a small capacitor (100 nF or so) over the supply
RRacer 7:cf5affdab535 31 // lines on each device on long cable runs significantly reduces the number of
RRacer 7:cf5affdab535 32 // bad readings.
RRacer 4:6ade7fcb2925 33 // If you make temperature conversions more often than every 4-5 seconds, the
RRacer 4:6ade7fcb2925 34 // device(s) will self heat and produce a higher temperature reading.
RRacer 4:6ade7fcb2925 35 //////////////////////////////////////////////////////////////////////////////
RRacer 4:6ade7fcb2925 36 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 37
RRacer 0:770734d973b0 38 #include <mbed.h>
RRacer 0:770734d973b0 39 Serial pc(USBTX, USBRX);
RRacer 0:770734d973b0 40
RRacer 0:770734d973b0 41 #define FALSE 0
RRacer 0:770734d973b0 42 #define TRUE 1
RRacer 0:770734d973b0 43 #define MaxROMs 20 // Defines how many devices space is allocated for.
RRacer 0:770734d973b0 44
RRacer 4:6ade7fcb2925 45 DigitalInOut DQ(p30); // Attach the DQ pin of your sensors to this mbed pin.
RRacer 0:770734d973b0 46
RRacer 0:770734d973b0 47 unsigned char SPad[9]; // Scratchpad storage
RRacer 0:770734d973b0 48 unsigned char ROM[8];
RRacer 0:770734d973b0 49 unsigned char lastDiscrep = 0; // last discrepancy
RRacer 0:770734d973b0 50 unsigned char doneFlag = 0; // Done flag
RRacer 0:770734d973b0 51 unsigned char FoundROM[MaxROMs][8]; // table of found ROM codes
RRacer 0:770734d973b0 52 unsigned char numROMs; // Number of found devices.
RRacer 0:770734d973b0 53 unsigned char dowcrc;
RRacer 0:770734d973b0 54 unsigned char dscrc_table[] = {
RRacer 0:770734d973b0 55 0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65,
RRacer 0:770734d973b0 56 157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220,
RRacer 0:770734d973b0 57 35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98,
RRacer 0:770734d973b0 58 190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255,
RRacer 0:770734d973b0 59 70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7,
RRacer 0:770734d973b0 60 219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154,
RRacer 0:770734d973b0 61 101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36,
RRacer 0:770734d973b0 62 248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185,
RRacer 0:770734d973b0 63 140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,
RRacer 0:770734d973b0 64 17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80,
RRacer 0:770734d973b0 65 175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,
RRacer 0:770734d973b0 66 50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,
RRacer 0:770734d973b0 67 202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139,
RRacer 0:770734d973b0 68 87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,
RRacer 0:770734d973b0 69 233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,
RRacer 0:770734d973b0 70 116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53};
RRacer 0:770734d973b0 71
RRacer 0:770734d973b0 72 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 73 // OW_RESET - performs a reset on the 1-wire bus and returns the presence detect.
RRacer 0:770734d973b0 74 unsigned char ow_reset(void) {
RRacer 0:770734d973b0 75 unsigned char presence;
RRacer 0:770734d973b0 76 DQ.output();
RRacer 0:770734d973b0 77 DQ = 0; //pull DQ line low
RRacer 0:770734d973b0 78 wait_us(480); // leave it low for 480us
RRacer 0:770734d973b0 79 DQ.input(); // allow line to return high
RRacer 0:770734d973b0 80 wait_us(70); // wait for presence
RRacer 0:770734d973b0 81 presence = DQ; // get presence signal
RRacer 0:770734d973b0 82 wait_us(410); // wait for end of timeslot
RRacer 4:6ade7fcb2925 83 return(presence); // presence signal returned, 0=presence, 1 = no sensor found.
RRacer 0:770734d973b0 84 }
RRacer 0:770734d973b0 85
RRacer 0:770734d973b0 86 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 87 // READ_BIT - reads a bit from the one-wire bus.
RRacer 0:770734d973b0 88 unsigned char read_bit(void) {
RRacer 0:770734d973b0 89 unsigned char retval;
RRacer 0:770734d973b0 90 wait_us(1); // Recovery time
RRacer 0:770734d973b0 91 DQ.output();
RRacer 0:770734d973b0 92 DQ = 0; // pull DQ low to start timeslot
RRacer 0:770734d973b0 93 wait_us(2);
RRacer 0:770734d973b0 94 DQ.input(); // Tristate line
RRacer 0:770734d973b0 95 wait_us(10); // delay 10 us from start of timeslot
RRacer 0:770734d973b0 96 retval=DQ;
RRacer 0:770734d973b0 97 wait_us(48); // minimum Read time slot: 60 us.
RRacer 0:770734d973b0 98 return(retval); // return value of DQ line
RRacer 0:770734d973b0 99 }
RRacer 0:770734d973b0 100
RRacer 0:770734d973b0 101 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 102 // WRITE_BIT - writes a bit to the one-wire bus, passed in bitval.
RRacer 0:770734d973b0 103 void write_bit(unsigned char bitval) {
RRacer 0:770734d973b0 104 wait_us(1); // Recovery time
RRacer 0:770734d973b0 105 DQ.output();
RRacer 0:770734d973b0 106 DQ = 0; // pull DQ low to start timeslot
RRacer 0:770734d973b0 107 wait_us(10);
RRacer 0:770734d973b0 108 if(bitval==1) DQ =1; // return DQ high if write 1
RRacer 0:770734d973b0 109 wait_us(50); // hold value for remainder of timeslot
RRacer 0:770734d973b0 110 DQ.input(); // Release line
RRacer 0:770734d973b0 111 }
RRacer 0:770734d973b0 112
RRacer 0:770734d973b0 113 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 114 // READ_BYTE - reads a byte from the one-wire bus.
RRacer 0:770734d973b0 115 unsigned char read_byte(void) {
RRacer 0:770734d973b0 116 unsigned char i, value=0;
RRacer 0:770734d973b0 117 for (i=0;i<8;i++) {
RRacer 0:770734d973b0 118 if(read_bit()) value|=0x01<<i; // reads byte in, one byte at a time and then shifts it left
RRacer 0:770734d973b0 119 }
RRacer 0:770734d973b0 120 return(value);
RRacer 0:770734d973b0 121 }
RRacer 0:770734d973b0 122
RRacer 0:770734d973b0 123 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 124 // WRITE_BYTE - writes a byte to the one-wire bus.
RRacer 0:770734d973b0 125 void write_byte(char val) {
RRacer 0:770734d973b0 126 unsigned char i;
RRacer 0:770734d973b0 127 unsigned char temp;
RRacer 0:770734d973b0 128 for (i=0; i<8; i++) {// writes byte, one bit at a time
RRacer 0:770734d973b0 129 temp = val>>i; // shifts val right 'i' spaces
RRacer 0:770734d973b0 130 temp &= 0x01; // copy that bit to temp
RRacer 4:6ade7fcb2925 131 write_bit(temp); // write bit
RRacer 0:770734d973b0 132 }
RRacer 0:770734d973b0 133 }
RRacer 0:770734d973b0 134
RRacer 0:770734d973b0 135 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 136 // ONE WIRE CRC
RRacer 0:770734d973b0 137 unsigned char ow_crc( unsigned char x) {
RRacer 0:770734d973b0 138 dowcrc = dscrc_table[dowcrc^x];
RRacer 0:770734d973b0 139 return dowcrc;
RRacer 0:770734d973b0 140 }
RRacer 0:770734d973b0 141
RRacer 0:770734d973b0 142 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 143 // NEXT
RRacer 0:770734d973b0 144 // The Next function searches for the next device on the 1-Wire bus. If
RRacer 0:770734d973b0 145 // there are no more devices on the 1-Wire then false is returned.
RRacer 0:770734d973b0 146 unsigned char Next(void) {
RRacer 0:770734d973b0 147 unsigned char m = 1; // ROM Bit index
RRacer 0:770734d973b0 148 unsigned char n = 0; // ROM Byte index
RRacer 0:770734d973b0 149 unsigned char k = 1; // bit mask
RRacer 0:770734d973b0 150 unsigned char x = 0;
RRacer 0:770734d973b0 151 unsigned char discrepMarker = 0; // discrepancy marker
RRacer 0:770734d973b0 152 unsigned char g; // Output bit
RRacer 0:770734d973b0 153 unsigned char nxt; // return value
RRacer 0:770734d973b0 154 int flag;
RRacer 4:6ade7fcb2925 155 nxt = FALSE; // set the nxt flag to false
RRacer 0:770734d973b0 156 dowcrc = 0; // reset the dowcrc
RRacer 0:770734d973b0 157 flag = ow_reset(); // reset the 1-Wire
RRacer 0:770734d973b0 158 if(flag||doneFlag) { // no parts -> return false
RRacer 0:770734d973b0 159 lastDiscrep = 0; // reset the search
RRacer 0:770734d973b0 160 return FALSE;
RRacer 0:770734d973b0 161 }
RRacer 0:770734d973b0 162 write_byte(0xF0); // send SearchROM command
RRacer 0:770734d973b0 163 do { // for all eight bytes
RRacer 0:770734d973b0 164 x = 0;
RRacer 0:770734d973b0 165 if(read_bit()==1) x = 2;
RRacer 0:770734d973b0 166 wait_us(120);
RRacer 0:770734d973b0 167 if(read_bit()==1) x |= 1; // and its complement
RRacer 0:770734d973b0 168 if(x ==3) // there are no devices on the 1-Wire
RRacer 0:770734d973b0 169 break;
RRacer 0:770734d973b0 170 else {
RRacer 0:770734d973b0 171 if(x>0) // all devices coupled have 0 or 1
RRacer 0:770734d973b0 172 g = x>>1; // bit write value for search
RRacer 0:770734d973b0 173 else {
RRacer 0:770734d973b0 174 // if this discrepancy is before the last discrepancy on a previous Next then pick the same as last time
RRacer 0:770734d973b0 175 if(m<lastDiscrep)
RRacer 0:770734d973b0 176 g = ((ROM[n]&k)>0);
RRacer 0:770734d973b0 177 else // if equal to last pick 1
RRacer 0:770734d973b0 178 g = (m==lastDiscrep); // if not then pick 0
RRacer 0:770734d973b0 179 // if 0 was picked then record position with mask k
RRacer 0:770734d973b0 180 if (g==0) discrepMarker = m;
RRacer 0:770734d973b0 181 }
RRacer 0:770734d973b0 182 if(g==1) // isolate bit in ROM[n] with mask k
RRacer 0:770734d973b0 183 ROM[n] |= k;
RRacer 0:770734d973b0 184 else
RRacer 0:770734d973b0 185 ROM[n] &= ~k;
RRacer 0:770734d973b0 186 write_bit(g); // ROM search write
RRacer 0:770734d973b0 187 m++; // increment bit counter m
RRacer 0:770734d973b0 188 k = k<<1; // and shift the bit mask k
RRacer 0:770734d973b0 189 if(k==0) { // if the mask is 0 then go to new ROM // byte n and reset mask
RRacer 0:770734d973b0 190 ow_crc(ROM[n]); // accumulate the CRC
RRacer 0:770734d973b0 191 n++; k++;
RRacer 0:770734d973b0 192 }
RRacer 0:770734d973b0 193 }
RRacer 0:770734d973b0 194 }
RRacer 0:770734d973b0 195 while(n<8); //loop until through all ROM bytes 0-7
RRacer 0:770734d973b0 196 if(m<65||dowcrc) // if search was unsuccessful then
RRacer 0:770734d973b0 197 lastDiscrep=0; // reset the last discrepancy to 0
RRacer 0:770734d973b0 198 else { // search was successful, so set lastDiscrep, lastOne, nxt
RRacer 0:770734d973b0 199 lastDiscrep = discrepMarker;
RRacer 0:770734d973b0 200 doneFlag = (lastDiscrep==0);
RRacer 0:770734d973b0 201 nxt = TRUE; // indicates search is not complete yet, more parts remain
RRacer 0:770734d973b0 202 }
RRacer 0:770734d973b0 203 return nxt;
RRacer 0:770734d973b0 204 }
RRacer 0:770734d973b0 205
RRacer 0:770734d973b0 206 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 207 // FIRST
RRacer 0:770734d973b0 208 // The First function resets the current state of a ROM search and calls
RRacer 0:770734d973b0 209 // Next to find the first device on the 1-Wire bus.
RRacer 0:770734d973b0 210 unsigned char First(void) {
RRacer 0:770734d973b0 211 lastDiscrep = 0; // reset the rom search last discrepancy global
RRacer 0:770734d973b0 212 doneFlag = FALSE;
RRacer 0:770734d973b0 213 return Next(); // call Next and return its return value
RRacer 0:770734d973b0 214 }
RRacer 0:770734d973b0 215
RRacer 0:770734d973b0 216 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 217 // FIND DEVICES
RRacer 0:770734d973b0 218 void FindDevices(void) {
RRacer 0:770734d973b0 219 unsigned char m;
RRacer 0:770734d973b0 220 if(!ow_reset()) { //Begins when a presence is detected
RRacer 0:770734d973b0 221 if(First()) { //Begins when at least one part is found
RRacer 0:770734d973b0 222 numROMs=0;
RRacer 0:770734d973b0 223 do {
RRacer 0:770734d973b0 224 numROMs++;
RRacer 0:770734d973b0 225 for(m=0;m<8;m++) {
RRacer 0:770734d973b0 226 FoundROM[numROMs][m]=ROM[m]; //Identifies ROM
RRacer 0:770734d973b0 227 }
RRacer 0:770734d973b0 228 pc.printf("ROM CODE =%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X %d\r\n",
RRacer 0:770734d973b0 229 FoundROM[numROMs][7],FoundROM[numROMs][6],FoundROM[numROMs][5],FoundROM[numROMs][4],
RRacer 0:770734d973b0 230 FoundROM[numROMs][3],FoundROM[numROMs][2],FoundROM[numROMs][1],FoundROM[numROMs][0],numROMs);
RRacer 0:770734d973b0 231 }
RRacer 0:770734d973b0 232 while (Next()&&(numROMs<MaxROMs)); //Continues until no additional devices are found
RRacer 0:770734d973b0 233 }
RRacer 0:770734d973b0 234 }
RRacer 0:770734d973b0 235 pc.printf("\n%d devices found.\r\n\n",numROMs);
RRacer 0:770734d973b0 236 }
RRacer 0:770734d973b0 237 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 238 void Read_ScratchPad(unsigned char n) { // Read the n first scratchpad bytes. Old data not wiped.
RRacer 0:770734d973b0 239 n=n % 10;
RRacer 0:770734d973b0 240 write_byte(0xBE);
RRacer 0:770734d973b0 241 for (int j=1;j<=n;j++){SPad[j-1]=read_byte();}
RRacer 0:770734d973b0 242 // CRC ********reserved******* Config Tl Th T MSB T LSB
RRacer 0:770734d973b0 243 pc.printf("\n ScratchPAD: %X%X%X%X%X%X%X%X%X\n",SPad[8],SPad[7],SPad[6],SPad[5],SPad[4],SPad[3],SPad[2],SPad[1],SPad[0]);
RRacer 0:770734d973b0 244 }
RRacer 0:770734d973b0 245
RRacer 0:770734d973b0 246 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 247 // Perform Match ROM
RRacer 0:770734d973b0 248 unsigned char Send_MatchRom(unsigned char DeviceNo) {
RRacer 0:770734d973b0 249 unsigned char i;
RRacer 0:770734d973b0 250 if(ow_reset()) return false;
RRacer 0:770734d973b0 251 write_byte(0x55); // match ROM
RRacer 0:770734d973b0 252 for(i=0;i<8;i++) {
RRacer 0:770734d973b0 253 write_byte(FoundROM[DeviceNo][i]); //send ROM code
RRacer 0:770734d973b0 254 }
RRacer 0:770734d973b0 255 return true;
RRacer 0:770734d973b0 256 }
RRacer 0:770734d973b0 257
RRacer 0:770734d973b0 258 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 259 void ConvT() { // Make all devices on the bus start a temperature conversion.
RRacer 0:770734d973b0 260 ow_reset();
RRacer 0:770734d973b0 261 write_byte( 0xcc); // Skip ROM command.
RRacer 0:770734d973b0 262 write_byte( 0x44); // Convert T command.
RRacer 0:770734d973b0 263 }
RRacer 0:770734d973b0 264
RRacer 0:770734d973b0 265 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 266 unsigned int ReadRawTemp(unsigned char device) {
RRacer 0:770734d973b0 267 int HighByte, LowByte;
RRacer 0:770734d973b0 268 Send_MatchRom(device); // Select device.
RRacer 0:770734d973b0 269 write_byte( 0xbe); // Read Scratchpad command.
RRacer 0:770734d973b0 270 LowByte=read_byte();
RRacer 0:770734d973b0 271 HighByte=read_byte();
RRacer 0:770734d973b0 272 return (HighByte << 8) + LowByte;
RRacer 0:770734d973b0 273 }
RRacer 0:770734d973b0 274
RRacer 0:770734d973b0 275 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 276 float Get_Temp(unsigned char device) {
RRacer 1:0777f93ef466 277 int Raw = ReadRawTemp(device);
RRacer 1:0777f93ef466 278 if((Raw>>8) & 0x80) { // Check if temperature is negative.
RRacer 1:0777f93ef466 279 Raw = (Raw ^ 0xFFFF) + 1;
RRacer 1:0777f93ef466 280 Raw *= -1;
RRacer 1:0777f93ef466 281 }
RRacer 1:0777f93ef466 282 float temperature = (float)Raw / 16.0;
RRacer 0:770734d973b0 283 return temperature;
RRacer 0:770734d973b0 284 }
RRacer 0:770734d973b0 285
RRacer 0:770734d973b0 286 //////////////////////////////////////////////////////////////////////////////
RRacer 0:770734d973b0 287 int main() {
RRacer 0:770734d973b0 288 float temperature;
RRacer 0:770734d973b0 289 DQ.output();
RRacer 0:770734d973b0 290 DQ = 0;
RRacer 0:770734d973b0 291 DQ.input();
RRacer 0:770734d973b0 292 pc.baud(9600);
RRacer 0:770734d973b0 293 pc.printf("\n\n*** Test with multiple DS18B20 ***\r\n\n");
RRacer 0:770734d973b0 294 pc.printf("Memory allocated for %d devices.\r\n",MaxROMs);
RRacer 0:770734d973b0 295 pc.printf("Scanning for devices...\r\n");
RRacer 0:770734d973b0 296 ow_reset();
RRacer 0:770734d973b0 297 FindDevices();
RRacer 0:770734d973b0 298 pc.printf("Scanning completed.\r\n");
RRacer 0:770734d973b0 299
RRacer 0:770734d973b0 300 while (1) {
RRacer 0:770734d973b0 301 ConvT(); // Issue Convert T command.
RRacer 0:770734d973b0 302 wait_ms(750); // Minimum 12-bit conversion time.
RRacer 0:770734d973b0 303 for(int i=1;i<=numROMs;i++) { // Cycle through found devices.
RRacer 0:770734d973b0 304 temperature = Get_Temp(i);
RRacer 0:770734d973b0 305 pc.printf("Temp: %08.4f Device: %02X%02X%02X%02X%02X%02X %03d\r\n",temperature,FoundROM[i][6],FoundROM[i][5],FoundROM[i][4],FoundROM[i][3],FoundROM[i][2],FoundROM[i][1],i);
RRacer 0:770734d973b0 306 }
RRacer 0:770734d973b0 307 pc.printf("\r\n");
RRacer 0:770734d973b0 308 wait(5); // Doing conversions more often will make devices self heat and produce a higher temperature reading.
RRacer 0:770734d973b0 309 }
RRacer 0:770734d973b0 310 }