Login / Register

Wifi Temperature Controller

If you’ve looked at some of my other posts, you’ll notice that I’ve played around with several DIY temperature controllers based around the Arduino, Teensy3.x, and Raspberry Pi. What’s been consistenly missing, although attempted, has been a WIFI-connected controller that is consistent, small, inexpensive and powerful.

The ESP8266 burst on the scene as a complete WIFI package that could be had for under five dollars. It contains a reasonably powerful CPU, FLASH and RAM, a complete on-board WIFI with TCP/UDP stack, and can be programmed in several languages, including the Arduino IDE with a suitable upgrade.

I worked up a small board that uses the ESP-01 (available for less that three dollars on eBay) and can track one DS18B20 1-Wire® temperature sensor, and two ds2406+ 1-Wire® switches. I have several boards that use the DS2406+ at my other website.

Using the modified Arduino IDE, I’ve written a program that will connect to your local WIFI intranet via DHCP or a static IP, find the 1-Wire® parts, and communicate via UDP to another master computer on your internet. Here’s a screenshot of the webpage that I’ve thrown together to monitor multiple boards:

ESP8266Net Monitor

The web software also saves the temerature/switch information to a MySQL database once a minute, and can display a graph of the ressults:

ESP8277 Graph

All of the code is available at my github site. The BOM is available here.

Leave a Reply