I bought from FunGizmos few DS18S20 temperature sensors to test for my small robot project and last week they finally got into my hands but only today I had the time to try them out.

To connect the sensors to the Arduino board I choose the parasite mode which derive power directly from the data line ( no need for an external power supply anymore ), below are the pinouts, the electronic scheme and a photo of the circuit (though, really simple as I used a breadboard) :

pinouts ds18s20

Arduino connection for Dallas DS18S20

After a little bit of research of Dallas’s one-wire interface and downloading the onewire library from Arduino.cc I came out with a nice function to detect all the DS18S20 and DS18B20 sensors from a one-wire bus.

Here is the detection and temperature reading code : tutorialpedia.

A sample of their output :

–Search started–
Device is a DS18S20 : 10-1D-30-F9-01-08-00-51
–Search ended–

for the detection code and

Temp = 79.25 F or 26.25 C
Temp = 79.14 F or 26.19 C
Temp = 79.14 F or 26.19 C
Temp = 79.25 F or 26.25 C

for the temperature retrieving code.

Other helpful links :
* onewire.h library
* Dallas DS18S20 official document