Ask any man over the age of 40 and they’ll likely tell you that you can tell if a pork shoulder is done just by looking at it and poking it well. You shouldn’t trust him because he’s lying. Don’t try to imitate his claimed abilities. We live in a technological utopia, and if we can collect objective data, there’s really no reason to rely on intuition. A good thermometer will let you know exactly if your smoker is at the right temperature and when to pull the meat. JayTongue’s Pi-tmaster is a great DIY option.
Pi-tmaster is an open source wireless thermometer that can read two sensors and that you can build yourself. There are plenty of products on the market with similar functionality, but this is a cool and affordable option for those who like to tinker. It has two K-type sensor connections, perfect for monitoring grill/smoker temperature and meat temperature at the same time. Connects to the user’s local WiFi network and makes temperature readings available as JSON data on a self-hosted website. The temperature is also displayed on a small OLED screen on the device itself.
As you might have already guessed from the hyphen in the name, JayTongue designed Pi-tmaster around the Raspberry Pi Pico W development board. Use the MAX6678 board to read K-type probes and make temperature data available through an easy-to-use SPI interface. Power is provided by a lithium battery via the LX-LCBST charging module.
All of this hardware is housed inside a clear waterproof hard case. It’s pre-drilled for the probe connection, which affects its ability to keep water out, but should be more than enough to deal with any light rain that might blow in during a night’s smoking.
To view the temperature, users visit a self-hosted website and review the JSON data. But it’s not very pretty, so JayTongue also wrote some Python scripts. One collects JSON data and the other puts it into nice graphs.
If you’d like to build your own Pi-tmaster, JayTongue has been kind enough to share all the file details on GitHub.
