Control a Mitsubishi heatpump using Particle Photon, Cloud, and MQTT

Made a little project and figured I’d share it here:

It’s a ready-to-go firmware app for controlling a Mitsubishi air conditioner / heatpump (often branded “Mr Slim”). Plenty of projects to do this on Arduino and ESP, but I love Particle hardware and cloud.

You can monitor status and control the device through Particle Cloud, MQTT, or both. Enjoy!


How did you connect to the Mr.Slim controller and did you dispense with the user interface? Thanks

Oh yeah, left that out!

So these devices have a diagnostic UART port and connector inside; makes it really easy. You can see a pinout at the upstream library’s project page:


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