Rob Dobson / RdGasUseMonitor

Monitor for central heating system (e.g. 2zones+hw) Supports up to 15 temp probes (DS18B20/DS18S20) 3 valve monitors Gas pulse meter recording Use stand-alone or with nodeEnergyServer See http://robdobson.com/2015/09/central-heating-monitor

Dependencies:   EthernetInterfacePlusHostname NTPClient Onewire RdWebServer SDFileSystem-RTOS mbed-rtos mbed-src

RdDS18B20.cpp@9:0e103c2f869a, 2015-02-22 (annotated)

Committer:
Bobty
Date:
Sun Feb 22 11:57:12 2015 +0000
Revision:
9:0e103c2f869a
Parent:
8:5980547ae71c
Child:
10:72eb217def1f
Moved thermometer code to separate class

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Bobty 8:5980547ae71c 1 // Handles OneWire temperature sensors DB18S20
Bobty 8:5980547ae71c 2 // Can handle multiple devices per pin
Bobty 8:5980547ae71c 3 // Rob Dobson, 2015
Bobty 8:5980547ae71c 4
Bobty 8:5980547ae71c 5 #include "RdDS18B20.h"
Bobty 8:5980547ae71c 6
Bobty 8:5980547ae71c 7 // #define SHOW_18B20_DEBUGGING 1
Bobty 8:5980547ae71c 8
Bobty 8:5980547ae71c 9 // Construct onewire bus with desired pin
Bobty 8:5980547ae71c 10 DS18B20::DS18B20(PinName mbedPin) : _oneWire(mbedPin)
Bobty 8:5980547ae71c 11 {
Bobty 8:5980547ae71c 12 _numValidAddresses = 0;
Bobty 9:0e103c2f869a 13 for (int i = 0; i < MAX_BUS_DEVICES; i++)
Bobty 9:0e103c2f869a 14 {
Bobty 9:0e103c2f869a 15 _temperatureTable[i] = INVALID_TEMPERATURE;
Bobty 9:0e103c2f869a 16 _timeOfReadingTable[i] = 0;
Bobty 9:0e103c2f869a 17 }
Bobty 8:5980547ae71c 18 }
Bobty 8:5980547ae71c 19
Bobty 8:5980547ae71c 20 // Request conversion
Bobty 8:5980547ae71c 21 void DS18B20::ReqConvert()
Bobty 8:5980547ae71c 22 {
Bobty 8:5980547ae71c 23 // Request conversion begins
Bobty 8:5980547ae71c 24 _oneWire.init();
Bobty 8:5980547ae71c 25 _oneWire.writeByte(0xCC);
Bobty 8:5980547ae71c 26 _oneWire.writeByte(0x44);
Bobty 8:5980547ae71c 27 }
Bobty 8:5980547ae71c 28
Bobty 8:5980547ae71c 29 // Get temperature
Bobty 9:0e103c2f869a 30 double DS18B20::ReadTemperature(int addrIdx)
Bobty 8:5980547ae71c 31 {
Bobty 8:5980547ae71c 32 // Check valid address
Bobty 8:5980547ae71c 33 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 9:0e103c2f869a 34 return INVALID_TEMPERATURE;
Bobty 8:5980547ae71c 35
Bobty 8:5980547ae71c 36 // Init the bus and req reading
Bobty 8:5980547ae71c 37 _oneWire.init();
Bobty 8:5980547ae71c 38 _oneWire.writeByte(0x55);
Bobty 8:5980547ae71c 39
Bobty 8:5980547ae71c 40 // Send the address
Bobty 8:5980547ae71c 41 for (int i = 0; i < 8; i++)
Bobty 8:5980547ae71c 42 _oneWire.writeByte(_addrTable[addrIdx][i]);
Bobty 8:5980547ae71c 43 _oneWire.writeByte(0xBE);
Bobty 8:5980547ae71c 44
Bobty 8:5980547ae71c 45 // Temperature val
Bobty 8:5980547ae71c 46 int temperatureVals[] = {0,0};
Bobty 8:5980547ae71c 47
Bobty 8:5980547ae71c 48 // Read values back
Bobty 8:5980547ae71c 49 for (int i = 0; i < sizeof(temperatureVals)/sizeof(int); i++)
Bobty 8:5980547ae71c 50 {
Bobty 8:5980547ae71c 51 temperatureVals[i] = _oneWire.readByte();
Bobty 8:5980547ae71c 52 }
Bobty 8:5980547ae71c 53 _oneWire.init();
Bobty 8:5980547ae71c 54
Bobty 8:5980547ae71c 55 // Convert temperature
Bobty 8:5980547ae71c 56 double temperature = ((temperatureVals[1] * 256) + temperatureVals[0])*0.0625;
Bobty 9:0e103c2f869a 57 _temperatureTable[addrIdx] = temperature;
Bobty 9:0e103c2f869a 58 _timeOfReadingTable[addrIdx] = time(NULL);
Bobty 8:5980547ae71c 59 return temperature;
Bobty 8:5980547ae71c 60 }
Bobty 8:5980547ae71c 61
Bobty 8:5980547ae71c 62 // Get address for a device
Bobty 9:0e103c2f869a 63 uint8_t* DS18B20::GetAddress(int addrIdx, uint8_t* addrBufPtr)
Bobty 8:5980547ae71c 64 {
Bobty 8:5980547ae71c 65 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 8:5980547ae71c 66 return _addrTable[0];
Bobty 9:0e103c2f869a 67 // Make a copy if non-null pointer passed in
Bobty 9:0e103c2f869a 68 if (addrBufPtr != NULL)
Bobty 9:0e103c2f869a 69 {
Bobty 9:0e103c2f869a 70 for( int i = 0; i < ONEWIRE_ADDR_BYTES; i++)
Bobty 9:0e103c2f869a 71 addrBufPtr[i] = _addrTable[addrIdx][i];
Bobty 9:0e103c2f869a 72 }
Bobty 8:5980547ae71c 73 return _addrTable[addrIdx];
Bobty 8:5980547ae71c 74 }
Bobty 8:5980547ae71c 75
Bobty 8:5980547ae71c 76 // Get address as a string
Bobty 8:5980547ae71c 77 char* DS18B20::GetAddressStr(int addrIdx)
Bobty 8:5980547ae71c 78 {
Bobty 8:5980547ae71c 79 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 8:5980547ae71c 80 return "";
Bobty 8:5980547ae71c 81 sprintf(_addrStr, "%02x %02x %02x %02x %02x %02x %02x %02x",
Bobty 8:5980547ae71c 82 _addrTable[addrIdx][0], _addrTable[addrIdx][1], _addrTable[addrIdx][2],
Bobty 8:5980547ae71c 83 _addrTable[addrIdx][3], _addrTable[addrIdx][4], _addrTable[addrIdx][5],
Bobty 8:5980547ae71c 84 _addrTable[addrIdx][6], _addrTable[addrIdx][7]);
Bobty 8:5980547ae71c 85 return _addrStr;
Bobty 8:5980547ae71c 86 }
Bobty 8:5980547ae71c 87
Bobty 8:5980547ae71c 88 // Debug print address
Bobty 8:5980547ae71c 89 void DS18B20::DebugPrintAddress(int addrIdx)
Bobty 8:5980547ae71c 90 {
Bobty 8:5980547ae71c 91 // Check valid address
Bobty 8:5980547ae71c 92 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 8:5980547ae71c 93 {
Bobty 8:5980547ae71c 94 printf("Invalid addrIdx %d", addrIdx);
Bobty 8:5980547ae71c 95 return;
Bobty 8:5980547ae71c 96 }
Bobty 8:5980547ae71c 97 // Write out address
Bobty 8:5980547ae71c 98 printf(GetAddressStr(addrIdx));
Bobty 8:5980547ae71c 99 }
Bobty 8:5980547ae71c 100
Bobty 9:0e103c2f869a 101 double DS18B20::GetLatestTemperature(int addrIdx, time_t& timeOfReading)
Bobty 9:0e103c2f869a 102 {
Bobty 9:0e103c2f869a 103 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 9:0e103c2f869a 104 return INVALID_TEMPERATURE;
Bobty 9:0e103c2f869a 105 timeOfReading = _timeOfReadingTable[addrIdx];
Bobty 9:0e103c2f869a 106 return _temperatureTable[addrIdx];
Bobty 9:0e103c2f869a 107 }
Bobty 9:0e103c2f869a 108
Bobty 8:5980547ae71c 109 void DS18B20::SearchToGetAddresses()
Bobty 8:5980547ae71c 110 {
Bobty 8:5980547ae71c 111 _numValidAddresses = 0;
Bobty 8:5980547ae71c 112 for (int addrIdx = 0; addrIdx < MAX_BUS_DEVICES; addrIdx++)
Bobty 8:5980547ae71c 113 {
Bobty 8:5980547ae71c 114 uint8_t addr[8];
Bobty 8:5980547ae71c 115
Bobty 8:5980547ae71c 116 if ( !_oneWire.search(addr))
Bobty 8:5980547ae71c 117 {
Bobty 8:5980547ae71c 118 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 119 printf("No more addresses.\r\n");
Bobty 8:5980547ae71c 120 #endif
Bobty 8:5980547ae71c 121 _oneWire.reset_search();
Bobty 8:5980547ae71c 122 break;
Bobty 8:5980547ae71c 123 }
Bobty 8:5980547ae71c 124
Bobty 8:5980547ae71c 125 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 126 printf("Found device addr (ROM) =");
Bobty 8:5980547ae71c 127 #endif
Bobty 9:0e103c2f869a 128 for( int i = 0; i < ONEWIRE_ADDR_BYTES; i++)
Bobty 8:5980547ae71c 129 {
Bobty 8:5980547ae71c 130 // Copy to table
Bobty 8:5980547ae71c 131 _addrTable[_numValidAddresses][i] = addr[i];
Bobty 8:5980547ae71c 132 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 133 printf(" %02x", addr[i]);
Bobty 8:5980547ae71c 134 #endif
Bobty 8:5980547ae71c 135 }
Bobty 8:5980547ae71c 136
Bobty 8:5980547ae71c 137 // Check CRC - only include if CRC is valid
Bobty 8:5980547ae71c 138 if (_oneWire.CRC(addr, ONEWIRE_ADDR_BYTES-1) == addr[ONEWIRE_ADDR_BYTES-1])
Bobty 8:5980547ae71c 139 _numValidAddresses++;
Bobty 8:5980547ae71c 140 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 141 else
Bobty 8:5980547ae71c 142 printf(" (CRC INVALID!)");
Bobty 8:5980547ae71c 143 #endif
Bobty 8:5980547ae71c 144
Bobty 8:5980547ae71c 145 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 146 // the first ROM byte indicates which chip
Bobty 8:5980547ae71c 147 switch (addr[0])
Bobty 8:5980547ae71c 148 {
Bobty 8:5980547ae71c 149 case 0x10:
Bobty 8:5980547ae71c 150 printf(" Chip = DS18S20\r\n"); // or old DS1820
Bobty 8:5980547ae71c 151 break;
Bobty 8:5980547ae71c 152 case 0x28:
Bobty 8:5980547ae71c 153 printf(" Chip = DS18B20\r\n");
Bobty 8:5980547ae71c 154 break;
Bobty 8:5980547ae71c 155 case 0x22:
Bobty 8:5980547ae71c 156 printf(" Chip = DS1822\r\n");
Bobty 8:5980547ae71c 157 break;
Bobty 8:5980547ae71c 158 default:
Bobty 8:5980547ae71c 159 printf(" NOT DS18x20 FAMILY\r\n");
Bobty 8:5980547ae71c 160 break;
Bobty 8:5980547ae71c 161 }
Bobty 8:5980547ae71c 162 #endif
Bobty 8:5980547ae71c 163 }
Bobty 8:5980547ae71c 164 }