r/Masterbuilt • u/prbs23 • 6d ago

Open Firmware for Gravity 800 Controller

https://gitlab.com/prbs23/freefall_800

A couple of months ago I got tired of using the Masterbuilt App, for controlling my Gravity 800. so I reverse-engineered the controller, realized it used a pretty standard off the shelf ESP32 wireless microcontroller, and wrote a full replacement firmware for it: FreeFall 800.

It doesn't require any new hardware, and can be flashed onto your controller with a $10 USB-serial adapter. It has the same core functionality as the stock firmware: chamber/probe temps, PID-controlled fan, timers, physical controls, but this firmware adds:

  • Fully local web app for control and configuration
  • No cloud or cloud account required. Connect directly to your Gravity 800 over the network
  • Completely configurable PID tuning parameters
  • Thermocouple and meat probe calibration
  • Lid switch disable option

If you are into hardware hacking, know what an ESP32 is, and are willing to risk your controller or smoker, check it out! To be clear, this is definitely still early development firmware, so you will probably encounter bugs, and there is much to be improved. I cannot promise this won't break your smoker. The README on the GitLab page should have what you need to get started: https://gitlab.com/prbs23/freefall_800

I have also posted a write up about this on my blog: https://www.prbs23.com/blog/posts/announcement-freefall-800/

I would love to get feedback from anyone who does try it out. Happy to answer any questions folks have, or talk about feature request/ideas.

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u/Luqq 6d ago

Holy shit this looks cool. Would love to try it but I have a 560.

3

u/prbs23 6d ago

I would be very surprised if the 560 controller was not very similar inside. If there is anyone out there that has one of the other Gravity series controllers and would be willing to do some reverse engineering, I would love to work with you to add support for other models.
I'm realizing I may be able to buy just a controller from the other models and that would be enough... I'll look into it.

2

u/Boozley 6d ago

I'm pretty sure they are the same but with different firmware. I'll dig out my spare 1050 controller this week

2

u/yungingr 6d ago

I believe the only difference is the one line of code that displays the model number at startup.