FreeFall 800

I recently released FreeFall 800, open source firmware for the Gravity 800 smoker/grill from Masterbuilt. The project started because I needed to open the controller to fix a broken wire. That is when I noticed that inside was a standard ESP32 module, with a plainly visible programming header. This made me very surprised to find that there were little to no details online about the controller’s internals. In this post I aim to document everything I managed to reverse engineer about the Gravity 800 controller board, and will discuss some of the very strange choices the designers made.

Today I’m publicly releasing a project I’ve been working on for a while: FreeFall 800. FreeFall 800 is a local first, open source firmware project, that replaces the factory firmware that comes on the Masterbuilt Gravity 800 smoker grill.

A year ago I was in the market for a new grill, and ended up purchasing a Masterbuilt Gravity 800 charcoal smoker grill. The grill itself has been great. However, like most “smart” devices, it has one fatal flaw: Without the internet, manufacturer’s servers, and their mobile app, you cannot make use of any of the “smart” remote control or monitoring features.