This is a Testing library
DS18B20.h@0:435141e08516, 2016-11-28 (annotated)
- Committer:
- javiersing
- Date:
- Mon Nov 28 12:59:53 2016 +0000
- Revision:
- 0:435141e08516
This is a Testing library
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
javiersing | 0:435141e08516 | 1 | #define MaxROMs 20 // Defines how many devices space is allocated for. |
javiersing | 0:435141e08516 | 2 | #define FALSE 0 |
javiersing | 0:435141e08516 | 3 | #define TRUE 1 |
javiersing | 0:435141e08516 | 4 | #include "FastIO.h" |
javiersing | 0:435141e08516 | 5 | unsigned char SPad[9]; // Scratchpad storage |
javiersing | 0:435141e08516 | 6 | unsigned char ROM[8]; |
javiersing | 0:435141e08516 | 7 | unsigned char lastDiscrep = 0; // last discrepancy |
javiersing | 0:435141e08516 | 8 | unsigned char doneFlag = 0; // Done flag |
javiersing | 0:435141e08516 | 9 | unsigned char FoundROM[MaxROMs][8]; // table of found ROM codes |
javiersing | 0:435141e08516 | 10 | unsigned char numROMs; // Number of found devices. |
javiersing | 0:435141e08516 | 11 | unsigned char dowcrc; |
javiersing | 0:435141e08516 | 12 | unsigned char dscrc_table[] = { |
javiersing | 0:435141e08516 | 13 | 0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65, |
javiersing | 0:435141e08516 | 14 | 157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220, |
javiersing | 0:435141e08516 | 15 | 35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98, |
javiersing | 0:435141e08516 | 16 | 190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255, |
javiersing | 0:435141e08516 | 17 | 70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7, |
javiersing | 0:435141e08516 | 18 | 219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154, |
javiersing | 0:435141e08516 | 19 | 101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36, |
javiersing | 0:435141e08516 | 20 | 248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185, |
javiersing | 0:435141e08516 | 21 | 140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205, |
javiersing | 0:435141e08516 | 22 | 17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80, |
javiersing | 0:435141e08516 | 23 | 175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238, |
javiersing | 0:435141e08516 | 24 | 50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115, |
javiersing | 0:435141e08516 | 25 | 202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139, |
javiersing | 0:435141e08516 | 26 | 87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22, |
javiersing | 0:435141e08516 | 27 | 233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168, |
javiersing | 0:435141e08516 | 28 | 116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53}; |
javiersing | 0:435141e08516 | 29 | |
javiersing | 0:435141e08516 | 30 | FastInOut<D2> DQ; // Use FastIO library to try an speed improvement and define the pin of input |
javiersing | 0:435141e08516 | 31 | Serial pc(USBTX, USBRX); |
javiersing | 0:435141e08516 | 32 | |
javiersing | 0:435141e08516 | 33 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 34 | // OW_RESET - performs a reset on the 1-wire bus and returns the presence detect. |
javiersing | 0:435141e08516 | 35 | unsigned char ow_reset(void) { |
javiersing | 0:435141e08516 | 36 | unsigned char presence; |
javiersing | 0:435141e08516 | 37 | DQ.output(); |
javiersing | 0:435141e08516 | 38 | DQ = 0; //pull DQ line low |
javiersing | 0:435141e08516 | 39 | wait_us(480); // leave it low for 480us |
javiersing | 0:435141e08516 | 40 | DQ.input(); // allow line to return high |
javiersing | 0:435141e08516 | 41 | wait_us(70); // wait for presence |
javiersing | 0:435141e08516 | 42 | presence = DQ; // get presence signal |
javiersing | 0:435141e08516 | 43 | wait_us(410); // wait for end of timeslot |
javiersing | 0:435141e08516 | 44 | return(presence); // presence signal returned, 0=presence, 1 = no sensor found. |
javiersing | 0:435141e08516 | 45 | } |
javiersing | 0:435141e08516 | 46 | |
javiersing | 0:435141e08516 | 47 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 48 | // READ_BIT - reads a bit from the one-wire bus. |
javiersing | 0:435141e08516 | 49 | unsigned char read_bit(void) { |
javiersing | 0:435141e08516 | 50 | unsigned char retval; |
javiersing | 0:435141e08516 | 51 | wait_us(1); // Recovery time |
javiersing | 0:435141e08516 | 52 | DQ.output(); |
javiersing | 0:435141e08516 | 53 | DQ = 0; // pull DQ low to start timeslot |
javiersing | 0:435141e08516 | 54 | wait_us(2); |
javiersing | 0:435141e08516 | 55 | DQ.input(); // Tristate line |
javiersing | 0:435141e08516 | 56 | wait_us(10); // delay 10 us from start of timeslot |
javiersing | 0:435141e08516 | 57 | retval=DQ; |
javiersing | 0:435141e08516 | 58 | wait_us(48); // minimum Read time slot: 60 us. |
javiersing | 0:435141e08516 | 59 | return(retval); // return value of DQ line |
javiersing | 0:435141e08516 | 60 | } |
javiersing | 0:435141e08516 | 61 | |
javiersing | 0:435141e08516 | 62 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 63 | // WRITE_BIT - writes a bit to the one-wire bus, passed in bitval. |
javiersing | 0:435141e08516 | 64 | void write_bit(unsigned char bitval) { |
javiersing | 0:435141e08516 | 65 | wait_us(1); // Recovery time |
javiersing | 0:435141e08516 | 66 | DQ.output(); |
javiersing | 0:435141e08516 | 67 | DQ = 0; // pull DQ low to start timeslot |
javiersing | 0:435141e08516 | 68 | wait_us(10); |
javiersing | 0:435141e08516 | 69 | if(bitval==1) DQ =1; // return DQ high if write 1 |
javiersing | 0:435141e08516 | 70 | wait_us(50); // hold value for remainder of timeslot |
javiersing | 0:435141e08516 | 71 | DQ.input(); // Release line |
javiersing | 0:435141e08516 | 72 | } |
javiersing | 0:435141e08516 | 73 | |
javiersing | 0:435141e08516 | 74 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 75 | // READ_BYTE - reads a byte from the one-wire bus. |
javiersing | 0:435141e08516 | 76 | unsigned char read_byte(void) { |
javiersing | 0:435141e08516 | 77 | unsigned char i, value=0; |
javiersing | 0:435141e08516 | 78 | for (i=0;i<8;i++) { |
javiersing | 0:435141e08516 | 79 | if(read_bit()) value|=0x01<<i; // reads byte in, one byte at a time and then shifts it left |
javiersing | 0:435141e08516 | 80 | } |
javiersing | 0:435141e08516 | 81 | return(value); |
javiersing | 0:435141e08516 | 82 | } |
javiersing | 0:435141e08516 | 83 | |
javiersing | 0:435141e08516 | 84 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 85 | // WRITE_BYTE - writes a byte to the one-wire bus. |
javiersing | 0:435141e08516 | 86 | void write_byte(char val) { |
javiersing | 0:435141e08516 | 87 | unsigned char i; |
javiersing | 0:435141e08516 | 88 | unsigned char temp; |
javiersing | 0:435141e08516 | 89 | for (i=0; i<8; i++) {// writes byte, one bit at a time |
javiersing | 0:435141e08516 | 90 | temp = val>>i; // shifts val right 'i' spaces |
javiersing | 0:435141e08516 | 91 | temp &= 0x01; // copy that bit to temp |
javiersing | 0:435141e08516 | 92 | write_bit(temp); // write bit |
javiersing | 0:435141e08516 | 93 | } |
javiersing | 0:435141e08516 | 94 | } |
javiersing | 0:435141e08516 | 95 | |
javiersing | 0:435141e08516 | 96 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 97 | // ONE WIRE CRC |
javiersing | 0:435141e08516 | 98 | unsigned char ow_crc( unsigned char x) { |
javiersing | 0:435141e08516 | 99 | dowcrc = dscrc_table[dowcrc^x]; |
javiersing | 0:435141e08516 | 100 | return dowcrc; |
javiersing | 0:435141e08516 | 101 | } |
javiersing | 0:435141e08516 | 102 | |
javiersing | 0:435141e08516 | 103 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 104 | // NEXT |
javiersing | 0:435141e08516 | 105 | // The Next function searches for the next device on the 1-Wire bus. If |
javiersing | 0:435141e08516 | 106 | // there are no more devices on the 1-Wire then false is returned. |
javiersing | 0:435141e08516 | 107 | unsigned char Next(void) { |
javiersing | 0:435141e08516 | 108 | unsigned char m = 1; // ROM Bit index |
javiersing | 0:435141e08516 | 109 | unsigned char n = 0; // ROM Byte index |
javiersing | 0:435141e08516 | 110 | unsigned char k = 1; // bit mask |
javiersing | 0:435141e08516 | 111 | unsigned char x = 0; |
javiersing | 0:435141e08516 | 112 | unsigned char discrepMarker = 0; // discrepancy marker |
javiersing | 0:435141e08516 | 113 | unsigned char g; // Output bit |
javiersing | 0:435141e08516 | 114 | unsigned char nxt; // return value |
javiersing | 0:435141e08516 | 115 | int flag; |
javiersing | 0:435141e08516 | 116 | nxt = FALSE; // set the nxt flag to false |
javiersing | 0:435141e08516 | 117 | dowcrc = 0; // reset the dowcrc |
javiersing | 0:435141e08516 | 118 | flag = ow_reset(); // reset the 1-Wire |
javiersing | 0:435141e08516 | 119 | if(flag||doneFlag) { // no parts -> return false |
javiersing | 0:435141e08516 | 120 | lastDiscrep = 0; // reset the search |
javiersing | 0:435141e08516 | 121 | return FALSE; |
javiersing | 0:435141e08516 | 122 | } |
javiersing | 0:435141e08516 | 123 | write_byte(0xF0); // send SearchROM command |
javiersing | 0:435141e08516 | 124 | do { // for all eight bytes |
javiersing | 0:435141e08516 | 125 | x = 0; |
javiersing | 0:435141e08516 | 126 | if(read_bit()==1) x = 2; |
javiersing | 0:435141e08516 | 127 | wait_us(120); |
javiersing | 0:435141e08516 | 128 | if(read_bit()==1) x |= 1; // and its complement |
javiersing | 0:435141e08516 | 129 | if(x ==3) // there are no devices on the 1-Wire |
javiersing | 0:435141e08516 | 130 | break; |
javiersing | 0:435141e08516 | 131 | else { |
javiersing | 0:435141e08516 | 132 | if(x>0) // all devices coupled have 0 or 1 |
javiersing | 0:435141e08516 | 133 | g = x>>1; // bit write value for search |
javiersing | 0:435141e08516 | 134 | else { |
javiersing | 0:435141e08516 | 135 | // if this discrepancy is before the last discrepancy on a previous Next then pick the same as last time |
javiersing | 0:435141e08516 | 136 | if(m<lastDiscrep) |
javiersing | 0:435141e08516 | 137 | g = ((ROM[n]&k)>0); |
javiersing | 0:435141e08516 | 138 | else // if equal to last pick 1 |
javiersing | 0:435141e08516 | 139 | g = (m==lastDiscrep); // if not then pick 0 |
javiersing | 0:435141e08516 | 140 | // if 0 was picked then record position with mask k |
javiersing | 0:435141e08516 | 141 | if (g==0) discrepMarker = m; |
javiersing | 0:435141e08516 | 142 | } |
javiersing | 0:435141e08516 | 143 | if(g==1) // isolate bit in ROM[n] with mask k |
javiersing | 0:435141e08516 | 144 | ROM[n] |= k; |
javiersing | 0:435141e08516 | 145 | else |
javiersing | 0:435141e08516 | 146 | ROM[n] &= ~k; |
javiersing | 0:435141e08516 | 147 | write_bit(g); // ROM search write |
javiersing | 0:435141e08516 | 148 | m++; // increment bit counter m |
javiersing | 0:435141e08516 | 149 | k = k<<1; // and shift the bit mask k |
javiersing | 0:435141e08516 | 150 | if(k==0) { // if the mask is 0 then go to new ROM // byte n and reset mask |
javiersing | 0:435141e08516 | 151 | ow_crc(ROM[n]); // accumulate the CRC |
javiersing | 0:435141e08516 | 152 | n++; k++; |
javiersing | 0:435141e08516 | 153 | } |
javiersing | 0:435141e08516 | 154 | } |
javiersing | 0:435141e08516 | 155 | } |
javiersing | 0:435141e08516 | 156 | while(n<8); //loop until through all ROM bytes 0-7 |
javiersing | 0:435141e08516 | 157 | if(m<65||dowcrc) // if search was unsuccessful then |
javiersing | 0:435141e08516 | 158 | lastDiscrep=0; // reset the last discrepancy to 0 |
javiersing | 0:435141e08516 | 159 | else { // search was successful, so set lastDiscrep, lastOne, nxt |
javiersing | 0:435141e08516 | 160 | lastDiscrep = discrepMarker; |
javiersing | 0:435141e08516 | 161 | doneFlag = (lastDiscrep==0); |
javiersing | 0:435141e08516 | 162 | nxt = TRUE; // indicates search is not complete yet, more parts remain |
javiersing | 0:435141e08516 | 163 | } |
javiersing | 0:435141e08516 | 164 | return nxt; |
javiersing | 0:435141e08516 | 165 | } |
javiersing | 0:435141e08516 | 166 | |
javiersing | 0:435141e08516 | 167 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 168 | // FIRST |
javiersing | 0:435141e08516 | 169 | // The First function resets the current state of a ROM search and calls |
javiersing | 0:435141e08516 | 170 | // Next to find the first device on the 1-Wire bus. |
javiersing | 0:435141e08516 | 171 | unsigned char First(void) { |
javiersing | 0:435141e08516 | 172 | lastDiscrep = 0; // reset the rom search last discrepancy global |
javiersing | 0:435141e08516 | 173 | doneFlag = FALSE; |
javiersing | 0:435141e08516 | 174 | return Next(); // call Next and return its return value |
javiersing | 0:435141e08516 | 175 | } |
javiersing | 0:435141e08516 | 176 | |
javiersing | 0:435141e08516 | 177 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 178 | // FIND DEVICES |
javiersing | 0:435141e08516 | 179 | void FindDevices(void) { |
javiersing | 0:435141e08516 | 180 | unsigned char m; |
javiersing | 0:435141e08516 | 181 | if(!ow_reset()) { //Begins when a presence is detected |
javiersing | 0:435141e08516 | 182 | if(First()) { //Begins when at least one part is found |
javiersing | 0:435141e08516 | 183 | numROMs=0; |
javiersing | 0:435141e08516 | 184 | do { |
javiersing | 0:435141e08516 | 185 | numROMs++; |
javiersing | 0:435141e08516 | 186 | for(m=0;m<8;m++) { |
javiersing | 0:435141e08516 | 187 | FoundROM[numROMs][m]=ROM[m]; //Identifies ROM |
javiersing | 0:435141e08516 | 188 | } |
javiersing | 0:435141e08516 | 189 | pc.printf("ROM CODE =%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X %d\r\n", |
javiersing | 0:435141e08516 | 190 | FoundROM[numROMs][7],FoundROM[numROMs][6],FoundROM[numROMs][5],FoundROM[numROMs][4], |
javiersing | 0:435141e08516 | 191 | FoundROM[numROMs][3],FoundROM[numROMs][2],FoundROM[numROMs][1],FoundROM[numROMs][0],numROMs); |
javiersing | 0:435141e08516 | 192 | } |
javiersing | 0:435141e08516 | 193 | while (Next()&&(numROMs<MaxROMs)); //Continues until no additional devices are found |
javiersing | 0:435141e08516 | 194 | } |
javiersing | 0:435141e08516 | 195 | } |
javiersing | 0:435141e08516 | 196 | pc.printf("\n%d devices found.\r\n\n",numROMs); |
javiersing | 0:435141e08516 | 197 | } |
javiersing | 0:435141e08516 | 198 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 199 | void Read_ScratchPad(unsigned char n) { // Read the n first scratchpad bytes. Old data not wiped. |
javiersing | 0:435141e08516 | 200 | n=n % 10; |
javiersing | 0:435141e08516 | 201 | write_byte(0xBE); |
javiersing | 0:435141e08516 | 202 | for (int j=1;j<=n;j++){SPad[j-1]=read_byte();} |
javiersing | 0:435141e08516 | 203 | // CRC ********reserved******* Config Tl Th T MSB T LSB |
javiersing | 0:435141e08516 | 204 | 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]); |
javiersing | 0:435141e08516 | 205 | } |
javiersing | 0:435141e08516 | 206 | |
javiersing | 0:435141e08516 | 207 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 208 | // Perform Match ROM |
javiersing | 0:435141e08516 | 209 | unsigned char Send_MatchRom(unsigned char DeviceNo) { |
javiersing | 0:435141e08516 | 210 | unsigned char i; |
javiersing | 0:435141e08516 | 211 | if(ow_reset()) return false; |
javiersing | 0:435141e08516 | 212 | write_byte(0x55); // match ROM |
javiersing | 0:435141e08516 | 213 | for(i=0;i<8;i++) { |
javiersing | 0:435141e08516 | 214 | write_byte(FoundROM[DeviceNo][i]); //send ROM code |
javiersing | 0:435141e08516 | 215 | } |
javiersing | 0:435141e08516 | 216 | return true; |
javiersing | 0:435141e08516 | 217 | } |
javiersing | 0:435141e08516 | 218 | |
javiersing | 0:435141e08516 | 219 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 220 | void ConvT() { // Make all devices on the bus start a temperature conversion. |
javiersing | 0:435141e08516 | 221 | ow_reset(); |
javiersing | 0:435141e08516 | 222 | write_byte( 0xcc); // Skip ROM command. |
javiersing | 0:435141e08516 | 223 | write_byte( 0x44); // Convert T command. |
javiersing | 0:435141e08516 | 224 | } |
javiersing | 0:435141e08516 | 225 | |
javiersing | 0:435141e08516 | 226 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 227 | unsigned int ReadRawTemp(unsigned char device) { |
javiersing | 0:435141e08516 | 228 | int HighByte, LowByte; |
javiersing | 0:435141e08516 | 229 | Send_MatchRom(device); // Select device. |
javiersing | 0:435141e08516 | 230 | write_byte( 0xbe); // Read Scratchpad command. |
javiersing | 0:435141e08516 | 231 | LowByte=read_byte(); |
javiersing | 0:435141e08516 | 232 | HighByte=read_byte(); |
javiersing | 0:435141e08516 | 233 | return (HighByte << 8) + LowByte; |
javiersing | 0:435141e08516 | 234 | } |
javiersing | 0:435141e08516 | 235 | |
javiersing | 0:435141e08516 | 236 | ////////////////////////////////////////////////////////////////////////////// |
javiersing | 0:435141e08516 | 237 | float Get_Temp(unsigned char device) { |
javiersing | 0:435141e08516 | 238 | int Raw = ReadRawTemp(device); |
javiersing | 0:435141e08516 | 239 | if((Raw>>8) & 0x80) { // Check if temperature is negative. |
javiersing | 0:435141e08516 | 240 | Raw = (Raw ^ 0xFFFF) + 1; |
javiersing | 0:435141e08516 | 241 | Raw *= -1; |
javiersing | 0:435141e08516 | 242 | } |
javiersing | 0:435141e08516 | 243 | float temperature = (float)Raw / 16.0; |
javiersing | 0:435141e08516 | 244 | return temperature; |
javiersing | 0:435141e08516 | 245 | } |
javiersing | 0:435141e08516 | 246 | |
javiersing | 0:435141e08516 | 247 | ////////////////////////////////////////////////////////////////////////////// |