Flashing CBU Module in New LSC Ceiling Lamp—Power Supply and CEN Pin Considerations

Hey there,
Currently I am working on the new LSC ceiling lamps.

When I opened the lamp, I found the CBU module which I need to flash.

I followed the approach of the following topic: https://www.elektroda.de/rtvforum/topic4016628.html

But it did not work for me. I don't think that my power supply (RasPi) is too weak.

I did not use the CEN pin because the other person did it without too 😅

Any ideas?

Welcome to forum! We will try to help you, let's check each possible fault scenario step by step.

How long are the wires? Wire length can cause issues.

Maybe RX and TX is swapped? Try swapping it.

Are you doing power off/on cycle correctly? By disconnecting 3.3V wire?

Did you try different baud rates?

Maybe there is something connected to TX/RX pins of CBU on your device and it interferes with connection?

How long are the wires? Wire length can cause issues.
Less than 15 cm. I don't think that's the issue. I could successfully flash an LN882 chip with this setup (https://www.elektroda.com/rtvforum/topic4091325.html)

Maybe RX and TX are swapped? Try swapping them.
Yeah, I tried that already. No success.

Are you doing power off/on cycle correctly? By disconnecting 3.3 V wire?
I did not ^^. Can you give me some details on that?

Did you try different baud rates?
I used 115200. Still not working
python3 uartprogram firmware_backup.bin -d /dev/serial0 -r -s 0x0 -l 0x200000 -b 115200
--> cannot get bus

Maybe there is something connected to TX/RX pins of CBU on your device and it interferes with connection?
The RX/TX pin is not soldered to the device. There is no connection between the device and the RX/TX pin.

When device is "getting bus", you need to do short power off/on cycles, by detaching 3.3V wire. It's a standard procedure for Beken chips. You must do it exactly when the flasher is trying to "get bus", not before it, and not too late.

>>21807876 Seems tricky to do it in a short time span ^^

The alternative would be to short/bridge CEN to ground?



I will test both strategies tomorrow. Thanks for the help

I think you should use our flasher, it gives more time to get bus.
https://github.com/openshwprojects/BK7231GUIFlashTool