TechZone A-D With OneWire

This article assumes a certain level of understanding of circuits and of the Arduino environment. It shows the circuit and the code neccesary to use a DS2760 High-Precision Li+ Battery Monitor chip to measure the temperature of the tip with a thermocouple. You can order the assembled circuit here and you can see how to hook it up and download the firmware here.Put link to instructions here If you need help getting this to work you can contact us.

Where the idea came from

This thermocouple circuit is based on the Paralax kit using the DS2760 High-Precision Li+ Battery Monitor. The DS2760 has internal temperature measurement capabilities as well as a high precision A-D used for measuring current. It is capable of measuring 6.25 uV per step. Another benefit of this chip is that it is designed to read current in both directions. This allows the thermocouple to be hooked up in either direction with just a little work in the code.

The Circuit

The circuit is simple, the thermocouple is hooked across the current sense pins, the enable pins are tied low and the communications pin is hooked up to one of the I2CP data pins. See the schematic below.

The Code

The first thing needed is a library for One Wire communications that can be obtained here. Thanks to Paul Stoffregen for compiling the work of several people into a complete and easily used library for one wire communications. Full credits can be viewed on the bottom of the page at that link.