///<summary> Retrieve the temperature from the OneWire sensor</summary>
///<param name="Sensors">Location of the bus for the OneWire sensors</param>
///<return>True if successful, false otherwise</return>
bool TemperatureSensor::RetrieveTemperatureFromSensor(OneWire Sensors)
{
float retVal = INVALID_DATA;
byte data[2];
//Found the sensor we were looking for, read the data from it
if(0 == Sensors.reset())
{
Logger::Log(F("Unable to reset the bus"), ERR);
goto cleanup;
}
Sensors.select(m_SensorAddress);
//Send the 0x44 command, which is the convert command
Sensors.write(0x44);
//TODO: Can only do this when not in parasitic power mode
while(Sensors.read() == 0)
{
//Chill for 5 ms to see if it's all done
delay(5);
}
//TODO: This might not be needed for non-parasite powered sensors
if(0 == Sensors.reset())
{
Logger::Log(F("Unable to reset the bus after converting temperature"), ERR);
goto cleanup;
}
Sensors.select(m_SensorAddress);
//Send the 0xBE command, which is read the scratchpad
Sensors.write(0xBE);
//The data is of the format LSB, MSB
data[0] = Sensors.read();
data[1] = Sensors.read();
retVal = ((data[1] << 8) | data[0]); //using two's compliment
retVal = retVal / 16.0;
retVal = Utility::ToFahrenheit(retVal);
//Reset the communication
Sensors.reset();
//Assign our temperature data
m_Temperature = retVal;
cleanup:
return retVal;
}
float getTemp(OneWire ds){
//returns the temperature from one DS18S20 in DEG Celsius
unsigned long currentMillis = millis();
static long previousMillis = 0;
if(currentMillis - previousMillis > TempSampleInterval) {
// save the last time you blinked the LED
previousMillis = currentMillis;
byte data[12];
byte addr[8];
if ( !ds.search(addr)) {
//no more sensors on chain, reset search
ds.reset_search();
return -1000;
}
if ( OneWire::crc8( addr, 7) != addr[7]) {
Serial.println("CRC is not valid!");
return -1000;
}
if ( addr[0] != 0x10 && addr[0] != 0x28) {
Serial.print("Device is not recognized");
return -1000;
}
ds.reset();
ds.select(addr);
ds.write(0x44,1); // start conversion, with parasite power on at the end
byte present = ds.reset();
ds.select(addr);
ds.write(0xBE); // Read Scratchpad
for (int i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
}
ds.reset_search();
byte MSB = data[1];
byte LSB = data[0];
float tempRead = ((MSB << 8) | LSB); //using two's compliment
float TemperatureSum = tempRead / 16;
// Serial.print("Temperature: ");
// Serial.print(TemperatureSum);
// Serial.print('\n');
return TemperatureSum;
}
}
void loop(void) {
byte i;
byte present = 0;
byte data[12];
byte addr[8];
if ( !ds.search(addr)) {
Serial.print("No more addresses.\n");
ds.reset_search();
delay(1250);
return;
}
Serial.print("R=");
for( i = 0; i < 8; i++) {
Serial.print(addr[i], HEX);
Serial.print(" ");
}
if ( OneWire::crc8( addr, 7) != addr[7]) {
Serial.print("CRC is not valid!\n");
return;
}
if ( addr[0] != 0x28) {
Serial.print("Device is not a DS18B20 family device.\n");
return;
}
// The DallasTemperature library can do all this work for you!
ds.reset();
ds.select(addr);
ds.write(0x44,1); // start conversion, with parasite power on at the end
delay(1000); // maybe 750ms is enough, maybe not
// we might do a ds.depower() here, but the reset will take care of it.
present = ds.reset();
ds.select(addr);
ds.write(0xBE); // Read Scratchpad
Serial.print("P=");
Serial.print(present,HEX);
Serial.print(" ");
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
Serial.print(data[i], HEX);
Serial.print(" ");
}
Serial.print(" CRC=");
Serial.print( OneWire::crc8( data, 8), HEX);
Serial.println();
}
float Temperature::getTemp(OneWire ds){
if ( !ds.search(_addr)) {
//no more sensors on chain, reset search
ds.reset_search();
return -1000;
}
if ( OneWire::crc8( _addr, 7) != _addr[7]) {
Serial.println("CRC is not valid!");
return -1000;
}
if ( _addr[0] != 0x10 && _addr[0] != 0x28) {
Serial.print("Device is not recognized");
return -1000;
}
ds.reset();
ds.select(_addr);
ds.write(0x44,1); // start conversion, with parasite power on at the end
_present = ds.reset();
ds.select(_addr);
ds.write(0xBE); // Read Scratchpad
for (int i = 0; i < 9; i++) { // we need 9 bytes
_data[i] = ds.read();
}
ds.reset_search();
_MSB = _data[1];
_LSB = _data[0];
_tempRead = ((_MSB << 8) | _LSB); //using two's compliment
_TemperatureSum = _tempRead / 16;
return _TemperatureSum;
}
void ReadTemp(Temp& reading) {
byte i;
byte present = 0;
byte type_s;
byte data[12];
if ( !ds.search(reading.addr)) {
ds.reset_search();
delay(250);
return;
}
if (OneWire::crc8(reading.addr, 7) != reading.addr[7]) {
Serial.println("CRC is not valid!");
return;
}
// the first ROM byte indicates which chip
switch (reading.addr[0]) {
case 0x10:
type_s = 1;
break;
case 0x28:
type_s = 0;
break;
case 0x22:
type_s = 0;
break;
default:
Serial.println("Device is not a DS18x20 family device.");
return;
}
ds.reset();
ds.select(reading.addr);
ds.write(0x44, 1); // start conversion, with parasite power on at the end
delay(750); // maybe 750ms is enough, maybe not
// we might do a ds.depower() here, but the reset will take care of it.
present = ds.reset();
ds.select(reading.addr);
ds.write(0xBE); // Read Scratchpad
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
}
// Convert the data to actual temperature
// because the result is a 16 bit signed integer, it should
// be stored to an "int16_t" type, which is always 16 bits
// even when compiled on a 32 bit processor.
int16_t raw = (data[1] << 8) | data[0];
if (type_s) {
raw = raw << 3; // 9 bit resolution default
if (data[7] == 0x10) {
// "count remain" gives full 12 bit resolution
raw = (raw & 0xFFF0) + 12 - data[6];
}
} else {
byte cfg = (data[4] & 0x60);
// at lower res, the low bits are undefined, so let's zero them
if (cfg == 0x00) raw = raw & ~7; // 9 bit resolution, 93.75 ms
else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
//// default is 12 bit resolution, 750 ms conversion time
}
reading.celsius = (raw / 16.0) * 100;
reading.didRead = true;
}
void loop(void) {
byte i;
byte present = 0;
byte type_s;
byte data[12];
byte addr[8];
float celsius, fahrenheit;
if ( !ds.search(addr)) {
Serial.println("No more addresses.");
Serial.println();
ds.reset_search();
delay(250);
return;
}
Serial.print("ROM =");
for( i = 0; i < 8; i++) {
Serial.write(' ');
Serial.print(addr[i], HEX);
}
if (OneWire::crc8(addr, 7) != addr[7]) {
Serial.println("CRC is not valid!");
return;
}
Serial.println();
// the first ROM byte indicates which chip
switch (addr[0]) {
case 0x10:
Serial.println(" Chip = DS18S20"); // or old DS1820
type_s = 1;
break;
case 0x28:
Serial.println(" Chip = DS18B20");
type_s = 0;
break;
case 0x22:
Serial.println(" Chip = DS1822");
type_s = 0;
break;
default:
Serial.println("Device is not a DS18x20 family device.");
return;
}
ds.reset();
ds.select(addr);
ds.write(0x44, 1); // start conversion, with parasite power on at the end
delay(1000); // maybe 750ms is enough, maybe not
// we might do a ds.depower() here, but the reset will take care of it.
present = ds.reset();
ds.select(addr);
ds.write(0xBE); // Read Scratchpad
Serial.print(" Data = ");
Serial.print(present, HEX);
Serial.print(" ");
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
Serial.print(data[i], HEX);
Serial.print(" ");
}
Serial.print(" CRC=");
Serial.print(OneWire::crc8(data, 8), HEX);
Serial.println();
// Convert the data to actual temperature
// because the result is a 16 bit signed integer, it should
// be stored to an "int16_t" type, which is always 16 bits
// even when compiled on a 32 bit processor.
int16_t raw = (data[1] << 8) | data[0];
if (type_s) {
raw = raw << 3; // 9 bit resolution default
if (data[7] == 0x10) {
// "count remain" gives full 12 bit resolution
raw = (raw & 0xFFF0) + 12 - data[6];
}
} else {
byte cfg = (data[4] & 0x60);
// at lower res, the low bits are undefined, so let's zero them
if (cfg == 0x00) raw = raw & ~7; // 9 bit resolution, 93.75 ms
else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
//// default is 12 bit resolution, 750 ms conversion time
}
celsius = (float)raw / 16.0;
fahrenheit = celsius * 1.8 + 32.0;
Serial.print(" Temperature = ");
Serial.print(celsius);
Serial.print(" Celsius, ");
Serial.print(fahrenheit);
Serial.println(" Fahrenheit");
}
/**
* Get a float representing the temperature from the DS18B20.
*
* @param ds OneWire instance configured for communication with the DS18B20.
* @return The average temperature in Fahrenheit of all devices, or 0 if fail.
*/
float DS18B20::getTemperature(OneWire ds) {
byte data[12]; // data buffer
byte addr[8]; // address buffer
byte deviceCount = 0; // number of devices taken care of
float avgTemp = 0.0; // the average temperature to be returned
// Search for a new device on the bus. If 1, a new device is available. If 0,
// the bus may be in error, nothing may be connected, or all devices have been
// read. This should allow for multiple sensors on the same bus (must remove
// else block). The address of the next device will be stored in addr.
ds.reset_search();
while (ds.search(addr)) {
// Count this device
deviceCount++;
// Verify the CRC of the address
if ( OneWire::crc8( addr, 7) != addr[7]) {
//Serial.println("CRC is not valid!");
return 0.0;
}
// Verify the device is recognized by looking at the device ID in the
// first byte of the address (=0x28).
if (addr[0] != DS18B20_CODE) {
//Serial.println("Device not recognized!");
return 0.0;
}
// Begin a temperature conversion
ds.reset();
ds.select(addr);
ds.write(CMD_CONVERT_TEMP); // 0x44 = start conversion
// Hard delay to get the most up-to-date reading. This gives the most time accurate reading
// but locks the processor up from doing anything else. The existing method where we read
// the *previous* reading every 1 second is suitable and increases utilization.
//delay(1000);
// Request to read the temperature sensor's scratchpad for the converted temperature
ds.reset();
ds.select(addr);
ds.write(CMD_READ_SPAD); // 0xBE = read scratchpad
// Read data (9 bytes total in register, only the first two bytes contain the temperature)
for (int i = 0; i < 9; i++) {
data[i] = ds.read();
}
// Convert read data (16 bit signed integer) to a float
int16_t temp_raw = (data[1] << 8) | data[0];
float temp_celsius = (float)temp_raw/16.0;
// Convert temperature to Fahrenheit and add it to our running average
float temp_fahrenheit = temp_celsius * 1.8 + 32.0;
avgTemp += temp_fahrenheit;
}
// If we didn't catch any devices, return 0.0
if (deviceCount == 0)
return 0.0;
// Compute and return the average
avgTemp /= deviceCount;
return avgTemp;
}
//-------------------------------------------------------------------------
float ReadSingleOneWireSensor(OneWire ds)
{
//--- 18B20 stuff
byte i;
byte type_s;
byte data[12];
byte addr[8];
float celsius = 12.3;
if (!ds.search(addr))
{
ds.reset_search();
delay(250);
return celsius;
}
if (OneWire::crc8(addr, 7) != addr[7])
{
return celsius;
}
//--- the first ROM byte indicates which chip
switch (addr[0])
{
case 0x10:
//Serial.println(" Chip = DS18S20"); // or old DS1820
type_s = 1;
break;
case 0x28:
// Serial.println(" Chip = DS18B20");
type_s = 0;
break;
case 0x22:
// Serial.println(" Chip = DS1822");
type_s = 0;
break;
default:
// Serial.println("Device is not a DS18x20 family device.");
return celsius;
}
ds.reset();
ds.select(addr);
ds.write(0x44,1 ); //--- start conversion, use alternatively ds.write(0x44,1) with parasite power on at the end
delay(1000); //--- maybe 750ms is enough, maybe not
//--- we might do a ds.depower() here, but the reset will take care of it.
ds.reset(); //--- DS18B20 responds with presence pulse
//--- match ROM 0x55, sensor sends ROM-code command ommitted here.
ds.select(addr);
ds.write(0xBE); //--- read scratchpad
for (i = 0; i < 9; i++)
{
//--- we need 9 bytes, 9th byte is CRC, first 8 are data
data[i] = ds.read();
}
//--- Convert the data to actual temperature
//--- because the result is a 16 bit signed integer, it should
//--- be stored to an "int16_t" type, which is always 16 bits
//--- even when compiled on a 32 bit processor.
int16_t raw = (data[1] << 8) | data[0];
if (type_s)
{
raw = raw << 3; //--- 9 bit resolution default
if (data[7] == 0x10)
{
//--- "count remain" gives full 12 bit resolution
raw = (raw & 0xFFF0) + 12 - data[6];
};
}
else
{
byte cfg = (data[4] & 0x60);
// at lower res, the low bits are undefined, so let's zero them
// default is 12 bit resolution, 750 ms conversion time
if (cfg == 0x00) raw = raw & ~7; // 9 bit resolution, 93.75 ms
else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
};
celsius = (float)raw / 16.0; //fahrenheit = celsius * 1.8 + 32.0;
//---- Check if any reads failed and exit early (to try again).
if (isnan(celsius))
{
//--- signalize error condition
celsius = -99.9;
};
return celsius;
}
