Local Thermoworks through ESPHome?

[cliffkujala]

@a2hill Thoughts on trying to go full local and flash ESPHome on these Thermoworks devices? I cracked open the RFX Gateway, and it is ESP32-WROOM-32E based. Also opened my SIGNALS and it is ESP32, but uses a naked board and I can't see which version it is using.

I can only imagine the Node and some of their other recent releases are probably ESP32 based as well.

I'm going to see if I can connect and dump the firmware from the RFX Gateway and SIGNALS devices.

[cliffkujala]

[a2hill]

To be honest I haven't really messed around with the ESP32 stuff before, but I'm certainly interested in going all local! How difficult was it getting the cases open? I'd open my Node but just don't want to break any clips or anything

[cliffkujala]

Not difficult. The RFX Gateway had little rubber bumpers covering 4 screw holes which easily came out with a finger nail, then a little spudger work to get the back half off. I pulled the entire board out as well just so I could visualize the entire setup, but the TX, RX, and GND pads are already exposed without doing that so it really isn't necessary to get some programming leads soldered onto those pads.

The SIGNALS was similar, except they used plastic plugs to cover the screws, so there was a tiny pit of marking leftover because I had to use a small pick to get those out.

[cliffkujala]

Struggled for a bit to get the RFX Gateway into Chip Boot Mode. Ultimately had to desolder the battery from the device, and power it with 3.3v to the VDD pad and strap IO0 to ground (there is another unlabeled pad connected to PIN25 which is IO0 so that is nice) while powering up. Firmware is backed up, but as it is proprietary to the manufacture I won't be posting it publicly.

Reverse engineering this to get it working as an ESPHome Device is probably beyond my abilities though tbh.

[a2hill]

Nice! Were you able to tell if both were running similar / the same firmware?

[cliffkujala]

I have not messed with the SIGNALS device yet. Still trying to write an ESPHome config for the RFX Gateway. May be a bit of a slow process as this is the first piece of manufactured ESP hardware I've tried to convert over to ESPHome, and they are using some chips I don't see as readily available in the ESPHome docs.

Honestly, the better approach might just be to stay on the stock firmware and go all Bluetooth, never pairing the Thermoworks devices to their cloud. Just intercept the local Bluetooth communications via a programmed Bluetooth proxy that knows which UUIDs to monitor.