GY-63_MS5611/libraries/DS18B20_RT/DS18B20.cpp
2022-11-02 15:21:25 +01:00

163 lines
3.1 KiB
C++

//
// FILE: DS18B20.cpp
// AUTHOR: Rob.Tillaart@gmail.com
// VERSION: 0.1.13
// DATE: 2017-07-25
// PUPROSE: library for DS18B20 temperature sensor with minimal footprint
// URL: https://github.com/RobTillaart/DS18B20_RT
//
// HISTORY: see changelog.md
#include "DS18B20.h"
// OneWire commands
#define STARTCONVO 0x44
#define READSCRATCH 0xBE
#define WRITESCRATCH 0x4E
// Scratchpad locations
#define TEMP_LSB 0
#define TEMP_MSB 1
#define HIGH_ALARM_TEMP 2
#define LOW_ALARM_TEMP 3
#define CONFIGURATION 4
#define INTERNAL_BYTE 5
#define COUNT_REMAIN 6
#define COUNT_PER_C 7
#define SCRATCHPAD_CRC 8
// Device resolution
#define TEMP_9_BIT 0x1F // 9 bit
#define TEMP_10_BIT 0x3F // 10 bit
#define TEMP_11_BIT 0x5F // 11 bit
#define TEMP_12_BIT 0x7F // 12 bit
DS18B20::DS18B20(OneWire* ow)
{
_oneWire = ow;
_addressFound = false;
_config = DS18B20_CLEAR;
}
bool DS18B20::begin(uint8_t retries)
{
_config = DS18B20_CLEAR;
_addressFound = false;
for (uint8_t rtr = retries; (rtr > 0) && (_addressFound == false); rtr--)
{
_oneWire->reset();
_oneWire->reset_search();
_deviceAddress[0] = 0x00;
_oneWire->search(_deviceAddress);
_addressFound = _deviceAddress[0] != 0x00 &&
_oneWire->crc8(_deviceAddress, 7) == _deviceAddress[7];
}
return _addressFound;
}
void DS18B20::readScratchPad(uint8_t *scratchPad, uint8_t fields)
{
_oneWire->reset();
_oneWire->select(_deviceAddress);
_oneWire->write(READSCRATCH);
for (uint8_t i = 0; i < fields; i++)
{
scratchPad[i] = _oneWire->read();
}
_oneWire->reset();
}
bool DS18B20::isConversionComplete(void)
{
return (_oneWire->read_bit() == 1);
}
void DS18B20::requestTemperatures(void)
{
_oneWire->reset();
_oneWire->skip();
_oneWire->write(STARTCONVO, 0);
}
float DS18B20::getTempC(void)
{
ScratchPad scratchPad;
for (int i = 0; i < 9; i++) scratchPad[i] = 0;
if (_config & DS18B20_CRC)
{
readScratchPad(scratchPad, 9);
if (_oneWire->crc8(scratchPad, 8) != scratchPad[SCRATCHPAD_CRC])
{
return DEVICE_CRC_ERROR;
}
}
else
{
readScratchPad(scratchPad, 2);
}
int16_t rawTemperature = (((int16_t)scratchPad[TEMP_MSB]) << 8) | scratchPad[TEMP_LSB];
float temp = 0.0625 * rawTemperature;
if (temp < -55)
{
return DEVICE_DISCONNECTED;
}
return temp;
}
void DS18B20::setResolution(uint8_t resolution)
{
_oneWire->reset();
_oneWire->select(_deviceAddress);
_oneWire->write(WRITESCRATCH);
// two dummy values for LOW & HIGH ALARM
_oneWire->write(0);
_oneWire->write(100);
switch (resolution)
{
case 12:
_oneWire->write(TEMP_12_BIT);
break;
case 11:
_oneWire->write(TEMP_11_BIT);
break;
case 10:
_oneWire->write(TEMP_10_BIT);
break;
case 9:
default:
_oneWire->write(TEMP_9_BIT);
break;
}
_oneWire->reset();
}
bool DS18B20::getAddress(uint8_t* buf)
{
if (_addressFound)
{
for (uint8_t i = 0; i < 8; i++)
{
buf[i] = _deviceAddress[i];
}
}
return _addressFound;
}
// -- END OF FILE --