• Making your own Temp-1Wire: Temperature sensor with RJ11 interface

    HWg-STE ethernet thermometer

    If you're lucky enough to have an HWg-STE ethernet thermometer for monitoring temps in your network closet or home theater cabinet, you know how hard it is to find the 1-wire temp sensor to complete both sensor inputs if you only have one sensor. In this short article I'll show you how to make one with a few parts from Home Depot and ebay.

    First go to Home Depot and buy an RJ11 cable. This is better known as a traditional phone cable. Get the length that you need for where the sensor will be located. While there, also look for the shrinkable heat shrink tubing which you can use to insulate the wires/sensor leads once you've soldered them on. If you can't find them here you can check any Radio Shack.

    DS1820 sensor

    Next, look on ebay and search for any of these terms "DS18B20 DS1820 1wire temperature sensor Dallas". It should look like the picture above and shouldn't cost you more than a dollar or two.

    Once you have the RJ11 cable, the shrink tubing and the sensor, you are ready to go. On to the pinouts.

    RJ11 cable pinouts

    1 - Not Used
    2 Data Transmit Data
    3 GND Ground
    4 +5V Power

    You will need to match these with the pinouts on the DS1820 sensor.

    DS1820 sensor pinouts

    Strip the wire as needed, slide the shrink tubing on to each little wire and then a bigger one over the bundle. Match up the pinouts and solder the RJ11 wires to the sensor. When done, use a lighter to shrink the shrink tubing over the leads to insulate them. Your finished product should look a lot like below.

    Temp-1Wire: Temperature sensor with RJ11 interface

    Plug your new sensor in to your HWg-STE ethernet thermometer, reboot it, and enjoy monitoring of your vital electronics!

    HWg-STE ethernet thermometer homepage