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@8:5980547ae71c, 2015-02-21 (annotated)

Committer:
Bobty
Date:
Sat Feb 21 19:00:08 2015 +0000
Revision:
8:5980547ae71c
Child:
9:0e103c2f869a
Working with thermometer test code

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 8:5980547ae71c 13 }
Bobty 8:5980547ae71c 14
Bobty 8:5980547ae71c 15 // Request conversion
Bobty 8:5980547ae71c 16 void DS18B20::ReqConvert()
Bobty 8:5980547ae71c 17 {
Bobty 8:5980547ae71c 18 // Request conversion begins
Bobty 8:5980547ae71c 19 _oneWire.init();
Bobty 8:5980547ae71c 20 _oneWire.writeByte(0xCC);
Bobty 8:5980547ae71c 21 _oneWire.writeByte(0x44);
Bobty 8:5980547ae71c 22 }
Bobty 8:5980547ae71c 23
Bobty 8:5980547ae71c 24 // Get temperature
Bobty 8:5980547ae71c 25 double DS18B20::GetTemperature(int addrIdx)
Bobty 8:5980547ae71c 26 {
Bobty 8:5980547ae71c 27 // Check valid address
Bobty 8:5980547ae71c 28 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 8:5980547ae71c 29 return -1000.0;
Bobty 8:5980547ae71c 30
Bobty 8:5980547ae71c 31 // Init the bus and req reading
Bobty 8:5980547ae71c 32 _oneWire.init();
Bobty 8:5980547ae71c 33 _oneWire.writeByte(0x55);
Bobty 8:5980547ae71c 34
Bobty 8:5980547ae71c 35 // Send the address
Bobty 8:5980547ae71c 36 for (int i = 0; i < 8; i++)
Bobty 8:5980547ae71c 37 _oneWire.writeByte(_addrTable[addrIdx][i]);
Bobty 8:5980547ae71c 38 _oneWire.writeByte(0xBE);
Bobty 8:5980547ae71c 39
Bobty 8:5980547ae71c 40 // Temperature val
Bobty 8:5980547ae71c 41 int temperatureVals[] = {0,0};
Bobty 8:5980547ae71c 42
Bobty 8:5980547ae71c 43 // Read values back
Bobty 8:5980547ae71c 44 for (int i = 0; i < sizeof(temperatureVals)/sizeof(int); i++)
Bobty 8:5980547ae71c 45 {
Bobty 8:5980547ae71c 46 temperatureVals[i] = _oneWire.readByte();
Bobty 8:5980547ae71c 47 }
Bobty 8:5980547ae71c 48 _oneWire.init();
Bobty 8:5980547ae71c 49
Bobty 8:5980547ae71c 50 // Convert temperature
Bobty 8:5980547ae71c 51 double temperature = ((temperatureVals[1] * 256) + temperatureVals[0])*0.0625;
Bobty 8:5980547ae71c 52 return temperature;
Bobty 8:5980547ae71c 53 }
Bobty 8:5980547ae71c 54
Bobty 8:5980547ae71c 55 // Get address for a device
Bobty 8:5980547ae71c 56 uint8_t* DS18B20::GetAddress(int addrIdx)
Bobty 8:5980547ae71c 57 {
Bobty 8:5980547ae71c 58 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 8:5980547ae71c 59 return _addrTable[0];
Bobty 8:5980547ae71c 60 return _addrTable[addrIdx];
Bobty 8:5980547ae71c 61 }
Bobty 8:5980547ae71c 62
Bobty 8:5980547ae71c 63 // Get address as a string
Bobty 8:5980547ae71c 64 char* DS18B20::GetAddressStr(int addrIdx)
Bobty 8:5980547ae71c 65 {
Bobty 8:5980547ae71c 66 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 8:5980547ae71c 67 return "";
Bobty 8:5980547ae71c 68 sprintf(_addrStr, "%02x %02x %02x %02x %02x %02x %02x %02x",
Bobty 8:5980547ae71c 69 _addrTable[addrIdx][0], _addrTable[addrIdx][1], _addrTable[addrIdx][2],
Bobty 8:5980547ae71c 70 _addrTable[addrIdx][3], _addrTable[addrIdx][4], _addrTable[addrIdx][5],
Bobty 8:5980547ae71c 71 _addrTable[addrIdx][6], _addrTable[addrIdx][7]);
Bobty 8:5980547ae71c 72 return _addrStr;
Bobty 8:5980547ae71c 73 }
Bobty 8:5980547ae71c 74
Bobty 8:5980547ae71c 75 // Debug print address
Bobty 8:5980547ae71c 76 void DS18B20::DebugPrintAddress(int addrIdx)
Bobty 8:5980547ae71c 77 {
Bobty 8:5980547ae71c 78 // Check valid address
Bobty 8:5980547ae71c 79 if ((addrIdx >= _numValidAddresses) || (addrIdx < 0))
Bobty 8:5980547ae71c 80 {
Bobty 8:5980547ae71c 81 printf("Invalid addrIdx %d", addrIdx);
Bobty 8:5980547ae71c 82 return;
Bobty 8:5980547ae71c 83 }
Bobty 8:5980547ae71c 84 // Write out address
Bobty 8:5980547ae71c 85 printf(GetAddressStr(addrIdx));
Bobty 8:5980547ae71c 86 }
Bobty 8:5980547ae71c 87
Bobty 8:5980547ae71c 88 void DS18B20::SearchToGetAddresses()
Bobty 8:5980547ae71c 89 {
Bobty 8:5980547ae71c 90 _numValidAddresses = 0;
Bobty 8:5980547ae71c 91 for (int addrIdx = 0; addrIdx < MAX_BUS_DEVICES; addrIdx++)
Bobty 8:5980547ae71c 92 {
Bobty 8:5980547ae71c 93 uint8_t addr[8];
Bobty 8:5980547ae71c 94
Bobty 8:5980547ae71c 95 if ( !_oneWire.search(addr))
Bobty 8:5980547ae71c 96 {
Bobty 8:5980547ae71c 97 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 98 printf("No more addresses.\r\n");
Bobty 8:5980547ae71c 99 #endif
Bobty 8:5980547ae71c 100 _oneWire.reset_search();
Bobty 8:5980547ae71c 101 break;
Bobty 8:5980547ae71c 102 }
Bobty 8:5980547ae71c 103
Bobty 8:5980547ae71c 104 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 105 printf("Found device addr (ROM) =");
Bobty 8:5980547ae71c 106 #endif
Bobty 8:5980547ae71c 107 for( int i = 0; i < 8; i++)
Bobty 8:5980547ae71c 108 {
Bobty 8:5980547ae71c 109 // Copy to table
Bobty 8:5980547ae71c 110 _addrTable[_numValidAddresses][i] = addr[i];
Bobty 8:5980547ae71c 111 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 112 printf(" %02x", addr[i]);
Bobty 8:5980547ae71c 113 #endif
Bobty 8:5980547ae71c 114 }
Bobty 8:5980547ae71c 115
Bobty 8:5980547ae71c 116 // Check CRC - only include if CRC is valid
Bobty 8:5980547ae71c 117 if (_oneWire.CRC(addr, ONEWIRE_ADDR_BYTES-1) == addr[ONEWIRE_ADDR_BYTES-1])
Bobty 8:5980547ae71c 118 _numValidAddresses++;
Bobty 8:5980547ae71c 119 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 120 else
Bobty 8:5980547ae71c 121 printf(" (CRC INVALID!)");
Bobty 8:5980547ae71c 122 #endif
Bobty 8:5980547ae71c 123
Bobty 8:5980547ae71c 124 #ifdef SHOW_18B20_DEBUGGING
Bobty 8:5980547ae71c 125 // the first ROM byte indicates which chip
Bobty 8:5980547ae71c 126 switch (addr[0])
Bobty 8:5980547ae71c 127 {
Bobty 8:5980547ae71c 128 case 0x10:
Bobty 8:5980547ae71c 129 printf(" Chip = DS18S20\r\n"); // or old DS1820
Bobty 8:5980547ae71c 130 break;
Bobty 8:5980547ae71c 131 case 0x28:
Bobty 8:5980547ae71c 132 printf(" Chip = DS18B20\r\n");
Bobty 8:5980547ae71c 133 break;
Bobty 8:5980547ae71c 134 case 0x22:
Bobty 8:5980547ae71c 135 printf(" Chip = DS1822\r\n");
Bobty 8:5980547ae71c 136 break;
Bobty 8:5980547ae71c 137 default:
Bobty 8:5980547ae71c 138 printf(" NOT DS18x20 FAMILY\r\n");
Bobty 8:5980547ae71c 139 break;
Bobty 8:5980547ae71c 140 }
Bobty 8:5980547ae71c 141 #endif
Bobty 8:5980547ae71c 142 }
Bobty 8:5980547ae71c 143 }