Novadigital 2 Channel Dimmer with CB3S Module: OpenBeken Firmware Integration Issues

I have a Novadigital 2-channel dimmer that I want to operate on alternative firmware.



I confirmed that the device uses the CB3S module, but here comes the difference from all other dimmers I have seen here: The CB3S module only talks to the onboard MCU (HK32F03MF4P6). Only the TX line from the CB3S to the MCU exists.

The S1 and S2 switches are connected directly to the CB3S module. Here is the wiring from the CB3S module (I had to desolder it to be able to track the circuit):
MCU <- TX1 (CB3S)
MCU -> RST (CB3S)
S1 -> P9 (CB3S)
S2 -> P8 (CB3S)
LED <- P6 (CB3S)
Reset button -> P24 (CB3S)

So, for now, I was able to dump the firmware and also upload OpenBeken, but I cannot configure it because of the said differences.
readResult...-16-31.bin (2 MB)You must be logged in to download this attachment.

Any ideas from the community?

Hey, thank you for posting. We'll try to help to get this running for you.
I think it;s either TuyaMCU or "girier MCU".

TuyaMCU resource:
https://www.elektroda.com/rtvforum/topic3898502.html

Girier:
https://www.elektroda.com/rtvforum/topic3985978.html
newer driver:
https://github.com/openshwprojects/OpenBK7231T_App/blob/main/src/driver/drv_girierMCU.c

Judging from the fact that switches are connected to the WiFi module, and not to the MCU, I'd say it's the latter. So I would try with:

I have managed to get your dump to pair with Tuya app with a cheap quick Python GrierMCU simulator. I see values changing as I adjust dimmers.

Great! That confirms, it's a Girirer. Can you share your script @divadiow ?

sure. it's probably doing too much or not enough. not refined. stopped development when device became visible to pair. pid may not be required but script mandates it at the moment

factory boot log for the record

Awesome, thank you all for the contributions!

With the information gathered here I was able to modify this dimmer and add a bunch of features. I did this on ESPHome, because I'm more familiar with it, and because my final objective was to integrate the dimmer in HomeAssistant. I believe this mods can also be implemented on OpenBeken, but I don't know how to to it.

What I have achieved on this device:
- Two‑speed dimming with adjustable intervals and trigger time
- Fully adjustable parameters for the dimmer: steps, speed, timings, etc.
- Direction reversal on every long press
- Persistent brightness and direction across reboots
- Automatic Home Assistant integration with a brightness slider using the ESPHome API.

I share the code I'm using bellow if someone is interested.

I share also a picture of the microcontroller board with it desoldered:


The dimmer is now under testing. I will come back with more information soon.