The new DS18B20 Temperature Sensor Module is a fully compatible Arduino platform that allows users to easily set up sensor networks. It's suitable for most DIY projects that require accurate temperature data. This module uses a single-bus digital temperature sensor DS18B20 with an external power supply voltage range of 3.0V to 5.0V (no standby power).

The DS18B20 looks like a normal transistor but be careful not to reverse the power and ground lines in order to avoid damaging it.

Test Code

# Include <OneWire.h>
/* DS18S20 Temperature chip i/o */
OneWire ds(10); // on pin 10

void setup(void) {
// Initialize inputs / outputs
// Start serial port
Serial.begin (9600);
}

void loop(void) {
byte i;
byte present = 0;
byte data[12];
byte addr[8];
int Temp;

if (! ds.search(addr)) {
// Serial.print("No more addresses. \ n");
ds.reset_search();
return;
}

Serial.print("R ="); // R = 28 Not sure what this is
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 DS18S20 family device. \ n");
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("P =");
Serial.print(present, HEX);
Serial.print("");

for (i = 0; i < 9; i++) { // we need 9 bytes
data [i] = ds.read();
}
}