Temperature-Sensing Coffee Coaster

Coffee is taken very seriously here at Digilent, as it is in most workplaces. Something that used to make me mad was not knowing when my coffee hit that perfect “Goldilocks” temperature zone where it didn’t burn my mouth but was warm enough to fully enjoy. I am currently working on developing a thermocouple Pmod using Analog Devices MAX31855 and thought of a great application project.   If I could somehow sense how hot the temperature of the coffee was, I could have a microcontroller tell me when my coffee hit the perfect temperature range!


This birthed the thermocouple coffee coaster, a 3D-printed coaster with a slot for the thermocouple to run through and touch the bottom of a mug. Using my circuit paired with a chipKIT Pro MX7, I was able to create a state machine informing me of the relative temperature of my coffee. For display purposes, I grabbed an old OLED2 module and drew some fun pictures.

Here is the coaster itself.
It’s designed by another engineering intern, Marshall.
The coaster allows for the thermocouple wire to run right up under the mug.
The breadboard circuit with which the chipKIT interfaces.
The final setup!


Now whenever my coffee is thermodynamically ripe, I’m notified and can enjoy my coffee and keep working efficiently. I have also posted a link to a video where you can see this thing in action with a song by the famous band “The PIC-Me-Ups” How nice of them to create a song just for this project!


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One Comment on “Temperature-Sensing Coffee Coaster”

  1. An amazing video… for a really functional project 🙂
    Thank you Sam for sharing!
    Do you have the code that someone could use to recreate your project?

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