Umair Aftab / Mbed 2 deprecated DS18B20MultipleSensors

Auto search for All DS18B20 sensors on data bus

Dependencies:   mbed

DS18B20Multiple/DS18B20.cpp@0:a2a81f538133, 2014-04-13 (annotated)

Committer:
umairaftab
Date:
Sun Apr 13 10:06:52 2014 +0000
Revision:
0:a2a81f538133
Multiple Sensors Functionality Added to Peter Sudensikis Library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
umairaftab 0:a2a81f538133 1 /*
umairaftab 0:a2a81f538133 2 * DS18B20. Maxim DS18B20 One-Wire Thermometer.
umairaftab 0:a2a81f538133 3 * Uses the OneWireCRC library.
umairaftab 0:a2a81f538133 4 *
umairaftab 0:a2a81f538133 5 * Copyright (C) <2010> Petras Saduikis <petras@petras.co.uk>
umairaftab 0:a2a81f538133 6 *
umairaftab 0:a2a81f538133 7 * This file is part of OneWireThermometer.
umairaftab 0:a2a81f538133 8 *
umairaftab 0:a2a81f538133 9 * OneWireThermometer is free software: you can redistribute it and/or modify
umairaftab 0:a2a81f538133 10 * it under the terms of the GNU General Public License as published by
umairaftab 0:a2a81f538133 11 * the Free Software Foundation, either version 3 of the License, or
umairaftab 0:a2a81f538133 12 * (at your option) any later version.
umairaftab 0:a2a81f538133 13 *
umairaftab 0:a2a81f538133 14 * OneWireThermometer is distributed in the hope that it will be useful,
umairaftab 0:a2a81f538133 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
umairaftab 0:a2a81f538133 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
umairaftab 0:a2a81f538133 17 * GNU General Public License for more details.
umairaftab 0:a2a81f538133 18 *
umairaftab 0:a2a81f538133 19 * You should have received a copy of the GNU General Public License
umairaftab 0:a2a81f538133 20 * along with OneWireThermometer. If not, see <http://www.gnu.org/licenses/>.
umairaftab 0:a2a81f538133 21 */
umairaftab 0:a2a81f538133 22
umairaftab 0:a2a81f538133 23 #include "DS18B20.h"
umairaftab 0:a2a81f538133 24 //#include "DebugTrace.h"
umairaftab 0:a2a81f538133 25
umairaftab 0:a2a81f538133 26 //DebugTrace pc_ds18B20(OFF, TO_SERIAL);
umairaftab 0:a2a81f538133 27
umairaftab 0:a2a81f538133 28 DS18B20::DS18B20( PinName pin) :
umairaftab 0:a2a81f538133 29 OneWireThermometer(pin, DS18B20_ID)
umairaftab 0:a2a81f538133 30 {
umairaftab 0:a2a81f538133 31 }
umairaftab 0:a2a81f538133 32
umairaftab 0:a2a81f538133 33 void DS18B20::setResolution(eResolution resln)
umairaftab 0:a2a81f538133 34 {
umairaftab 0:a2a81f538133 35 // as the write to the configuration register involves a write to the
umairaftab 0:a2a81f538133 36 // high and low alarm bytes, need to read these registers first
umairaftab 0:a2a81f538133 37 // and copy them back on the write
umairaftab 0:a2a81f538133 38
umairaftab 0:a2a81f538133 39 BYTE read_data[THERMOM_SCRATCHPAD_SIZE];
umairaftab 0:a2a81f538133 40 BYTE write_data[ALARM_CONFIG_SIZE];
umairaftab 0:a2a81f538133 41
umairaftab 0:a2a81f538133 42 if (readAndValidateData(read_data))
umairaftab 0:a2a81f538133 43 {
umairaftab 0:a2a81f538133 44 // copy alarm and config data to write data
umairaftab 0:a2a81f538133 45 for (int k = 2; k < 5; k++)
umairaftab 0:a2a81f538133 46 {
umairaftab 0:a2a81f538133 47 write_data[k - 2] = read_data[k];
umairaftab 0:a2a81f538133 48 }
umairaftab 0:a2a81f538133 49 int config = write_data[2];
umairaftab 0:a2a81f538133 50 config &= 0x9F;
umairaftab 0:a2a81f538133 51 config ^= (resln << 5);
umairaftab 0:a2a81f538133 52 write_data[2] = config;
umairaftab 0:a2a81f538133 53
umairaftab 0:a2a81f538133 54 resetAndAddress();
umairaftab 0:a2a81f538133 55 oneWire.writeByte(WRITESCRATCH);
umairaftab 0:a2a81f538133 56 for (int k = 0; k < 3; k++)
umairaftab 0:a2a81f538133 57 {
umairaftab 0:a2a81f538133 58 oneWire.writeByte(write_data[k]);
umairaftab 0:a2a81f538133 59 }
umairaftab 0:a2a81f538133 60
umairaftab 0:a2a81f538133 61 // remember it so we can use the correct delay in reading the temperature
umairaftab 0:a2a81f538133 62 // for parasitic power
umairaftab 0:a2a81f538133 63 resolution = resln;
umairaftab 0:a2a81f538133 64 }
umairaftab 0:a2a81f538133 65 }
umairaftab 0:a2a81f538133 66
umairaftab 0:a2a81f538133 67 float DS18B20::calculateTemperature(BYTE* data)
umairaftab 0:a2a81f538133 68 {
umairaftab 0:a2a81f538133 69 bool signBit = false;
umairaftab 0:a2a81f538133 70 if (data[TEMPERATURE_MSB] & 0x80) signBit = true;
umairaftab 0:a2a81f538133 71
umairaftab 0:a2a81f538133 72 int read_temp = (data[TEMPERATURE_MSB] << 8) + data[TEMPERATURE_LSB];
umairaftab 0:a2a81f538133 73 if (signBit)
umairaftab 0:a2a81f538133 74 {
umairaftab 0:a2a81f538133 75 read_temp = (read_temp ^ 0xFFFF) + 1; // two's complement
umairaftab 0:a2a81f538133 76 read_temp *= -1;
umairaftab 0:a2a81f538133 77 }
umairaftab 0:a2a81f538133 78
umairaftab 0:a2a81f538133 79 int resolution = (data[CONFIG_REG_BYTE] & 0x60) >> 5; // mask off bits 6,5 and move to 1,0
umairaftab 0:a2a81f538133 80 switch (resolution)
umairaftab 0:a2a81f538133 81 {
umairaftab 0:a2a81f538133 82 case nineBit: // 0.5 deg C increments
umairaftab 0:a2a81f538133 83 read_temp &= 0xFFF8; // bits 2,1,0 are undefined
umairaftab 0:a2a81f538133 84 //pc_ds18B20.traceOut("9 bit resolution ...\r\n");
umairaftab 0:a2a81f538133 85 break;
umairaftab 0:a2a81f538133 86 case tenBit: // 0.25 deg C increments
umairaftab 0:a2a81f538133 87 read_temp &= 0xFFFC; // bits 1,0 are undefined
umairaftab 0:a2a81f538133 88 //pc_ds18B20.traceOut("10 bit resolution ...\r\n");
umairaftab 0:a2a81f538133 89 break;
umairaftab 0:a2a81f538133 90 case elevenBit: // 0.125 deg C increments
umairaftab 0:a2a81f538133 91 read_temp &= 0xFFFE; // bit 0 is undefined
umairaftab 0:a2a81f538133 92 //pc_ds18B20.traceOut("11 bit resolution ...\r\n");
umairaftab 0:a2a81f538133 93 break;
umairaftab 0:a2a81f538133 94 case twelveBit: // 0.0625 deg C increments
umairaftab 0:a2a81f538133 95 //pc_ds18B20.traceOut("12 bit resolution ...\r\n");
umairaftab 0:a2a81f538133 96 break;
umairaftab 0:a2a81f538133 97 }
umairaftab 0:a2a81f538133 98 float realTemp = (float)read_temp/16 ;
umairaftab 0:a2a81f538133 99
umairaftab 0:a2a81f538133 100 //pc_ds18B20.traceOut("TEMP_READ/REAL TEMP: %f \r\n", realTemp);
umairaftab 0:a2a81f538133 101
umairaftab 0:a2a81f538133 102 return realTemp;
umairaftab 0:a2a81f538133 103 }