Tuya WiFi Ceiling Lamp KZB2436-36W: Flashing with OpenBeken, Tips, and Troubleshooting

Hi everyone. I'm pretty much a noob about this stuff although I flashed a few devices with Tasmota. However, now I have a ceiling light with a CBU module and it doesn't seem anyone has been flashing it already and would like to make sure it will still work if I go that route with OpenBeken. So I would need some help here. I am really tired of Tuya limitations and troubles with it. Almost every day it changes IP although I have DHCP static IP set in the router (could be a router problem). I use it with LocalTuya. I have to take power off and back on for it to get back set IP.

CBU module datasheet I found on Tuya:
https://developer.tuya.com/en/docs/iot/cbu-module-datasheet?id=Ka07pykl5dk4u

It is supposed to have a BK7231N chip.

I ordered the lamp from AliExpress:
https://a.aliexpress.com/_mOnNYEi







If there is any additional info I can provide, let me know.

After all, I really like the design and performance of the light when there are no problems and would be really happy if I can flash it.

I think that CBU should be very easily flashable with hid_download_py:
https://github.com/OpenBekenIOT/hid_download_py
First do firmware read (full 2MB), and then flash Obk:


NOTE: replace OpenBK7231N_QIO_1.15.206.bin with latest one...
ALSO don't compile yourself, releases are here: https://github.com/openshwprojects/OpenBK7231T_App/releases
For flashing, you need to connect 3.3V, GND, TX, RX and maybe CEN.

Pin number	Symbol	I/O type	Function
1	P14	I/O	Common GPIO, which can be reused as SPI_SCK (Correspond to Pin 11 of the IC)
2	P16	I/O	Common GPIO, which can be reused as SPI_MOSI (Correspond to Pin 12 of the IC)
3	P20	I/O	Common GPIO (Correspond to Pin 20 of the IC)
4	P22	I/O	Common GPIO (Correspond to Pin 18 of the IC)
5	ADC	I/O	ADC, which corresponds to P23 on the internal IC (Correspond to Pin 17 of the IC)
6	RX2	I/O	UART_RX2, which corresponds to P1 on the internal IC. (Correspond to Pin 28 of the IC)
7	TX2	I/O	UART_TX2, which is used for outputting logs and corresponds to P0 of the internal IC (Correspond to Pin 29 of the IC)
8	P8	I/O	Support hardware PWM (Correspond to Pin 24 of the IC)
9	P7	I/O	Support hardware PWM (Correspond to Pin 23 of the IC)
10	P6	I/O	Support hardware PWM (Correspond to Pin 22 of the IC)
11	P26	I/O	Support hardware PWM (Correspond to Pin 15 of the IC)
12	P24	I/O	Support hardware PWM (Correspond to Pin 16 of the IC)
13	GND	P	Power supply reference ground
14	3V3	P	Power supply 3V3
15	TX1	I/O	UART_TX1, which is used for transmitting user data and corresponds to Pin 27 of the IC. For the MCU solution, please refer to CBx Module.
16	RX1	I/O	UART_RX1, which is used for receiving user data and corresponds to Pin 26 of the IC. For the MCU solution, please refer to CBx Module.
17	P28	I/O	Common GPIO (Correspond to Pin 10 of the IC)
18	CEN	I/O	Reset pin, low active (internally pulled high), compatible with other modules (Correspond to Pin 21 of the IC)
19	P9	I/O	Common GPIO (Correspond to Pin 25 of the IC)
20	P17	I/O	Common GPIO, which can be reused as SPI_MISO (Correspond to Pin 14 of the IC)
21	P15	I/O	Common GPIO, which can be reused as SPI_CS (Correspond to Pin 13 of the IC)
Test point	CSN	I/O	Mode selection pin. If it is connected to the ground before being powered on, enter the firmware test mode. If it is not connected or connected to VCC before being powered on, enter the firmware application mode. Correspond to Pin 19 on the internal IC.

You can find more details about BK7231N flashing on our video:

NOTE: I hope you are aware about basics, like, you should never operate on device connected to mains, etc? Disconnect everything from mains first. Power device from your own reliable 3.3V source (it should be able to supply enough current), etc.

How do I set up python virtual environment if I have to? What do I have to do, I have never used this.. I downloaded the https://github.com/OpenBekenIOT/hid_download_py and run install.bat

First I got this in cmd:
C:UsersRushDesktophid_download_py-master>python uartprogram myfirmwarebackup.bin -d com8 -r -s 0x0 -l 0x200000
UartDownloader....
Read Getting Bus...
Cannot get bus.
Traceback (most recent call last):
File "C:UsersRushDesktophid_download_py-masteruartprogram", line 56, in
downloader.read(args.filename, args.startaddr, args.length)
File "C:UsersRushDesktophid_download_py-masterbkutilsuart_downloader.py", line 83, in read
self.pbar.close()
AttributeError: 'NoneType' object has no attribute 'close'

now in cmd with the first command I get:
Traceback (most recent call last):
File "C:UsersRushDesktophid_download_py-masteruartprogram", line 14, in
from bkutils import UartDownloader
File "C:UsersRushDesktophid_download_py-masterbkutils__init__.py", line 3, in
from .uart_downloader import *
File "C:UsersRushDesktophid_download_py-masterbkutilsuart_downloader.py", line 16, in
from tqdm import tqdm
ModuleNotFoundError: No module named 'tqdm'

I have no programming skills really..

Added after 3 [minutes]:

https://medium.com/analytics-vidhya/virtual-environment-6ad5d9b6af59

Should I follow this steps or something?

Hello, it looks like you don't have tqdm.

Have you tried to install tqdm?

https://stackoverflow.com/questions/47529792/no-module-named-tqdm
or pip3

but this:

means that you got it working before, but now tqdm is missing?

Ok now I only get this error.. I had to set path, hope i made it right by some googling.. as there was warning i don't have PATH. Then it said tqdm is installed.

Read Getting Bus...
Cannot get bus.
Traceback (most recent call last):
File "C:\Users\Rush\Desktop\hid_download_py-master\uartprogram", line 56, in <module>
downloader.read(args.filename, args.startaddr, args.length)
File "C:\Users\Rush\Desktop\hid_download_py-master\bkutils\uart_downloader.py", line 83, in read
self.pbar.close()
AttributeError: 'NoneType' object has no attribute 'close'

Well its the same error, i opened CMD as administrator now.. How to solve this now?

Added after 4 [minutes]:

I tryed shorting GND and CEN when reading bus, but same.

I use CH340G USB to TTL, i used its 3.3v and ground, like for all Esp's i flashed. is that alright?

Added after 38 [minutes]:

Hmm gotten some progress when shorting CEN and GND at right time. But then some errors. Should it be kept shorted all the time?

Added after 3 [minutes]:

Read Getting Bus...
Gotten Bus...
Set baudrate successful
len: 200000
startAddr: 0
Reading 0
ReadSector Success 0 len 1000
4096
Reading 1000
ReadSector Success 1000 len 1000
8192
Reading 2000
ReadSector Success 2000 len 1000
12288
Reading 3000
ReadSector Success 3000 len 620
ReadSector Failed, len not 0x1000 620

Read Getting Bus...
Gotten Bus...
Set baudrate failed

Added after 3 [minutes]:

Thats tricky, now it almost went through? at the end:
CRC should be 49976dc5
CRC is fe2a888f
CRC check failed
Wrote 200000 bytes to myfirmwarebackup.bin

CEN should be shorted to GND for 0.2 seconds (originally, it was done automatically by the Beken flashing tool). Then the "Getting bus" will "get bus" and start flashing.

It is tricky to short CEN to GND for a correct amount of time - takes several tries to do that.

Ok I managed to write it. Now let me try accessing it and all that :)

Added after 56 [minutes]:

Well it's working, managed to set it up.

Before I did set it up the right way, I checked this:
Flag 8 - [LED] Alternate CW light mode (first PWM for warm/cold slider, second for brightness)
And it seemed that it was much brighter on warm-slider side = both channels had 100%. Is that safe for the lamp or will I burn something if I wanted to use that option sometimes to get the most brightness out of it?

Oh and one more thing. How could I set static IP on device itself?

After all, thank you so much for your time and your investment into developing such a nice tasmota alternative firmware. Very nice work

Currently we just assumed that users set static IP by doing a MAC reservation on the router DHCP client. Do you need to be able to set a static IP on the device itself?

rush56 wrote:

Before i did set it up the right way, i checked this:
Flag 8 - [LED] Alternate CW light mode (first PWM for warm/cold slider, second for brightness)
And it seemed that it was much brighter on warm-slider side = both channels had 100%. Is that safe for the lamp or will i burn something if i wanted to use that option sometimes to get the most brightness out of it?

That option is for a special case where the driver expects not direct drive of PWM LED, but uses one LED for brightness and second for cool/warm choice (0% duty = cool, 100% duty = warm). If you have a normal LED drivers, and connect them in that way that both cool and warm channels are 100% bright, then you are using the device outside the expected range and it may overheat faster.

I also remember that in the past I was playing with RGBCW LED bulbs (E27, big ones) and when I forced all channels to 100%, the bulb simply turned off - the LED current driver just detected that too much current were taken and safety shut down the LEDs until next device reboot.

Thanks for details.

I probably don't need static ip now, as it's through mqtt, but with localtuya I needed it. And although I had it set on router, as I already wrote, it lost set ip after lease time. After power off and on it got it back. That was daily. When I set lease time to 0, we had a lot of trouble with our wifi at home. Could be faulty routers dhcp, as this happened with other devices too. I did use wireshark to check for any other dhcp server and there was none. I also disabled dhcp and my laptop kept connecting, not getting any ip. So I assume it's routers fault.

I am using MAC reservation on about 25 devices and it works reliably.

Futhermore, I have "startDriver SSDP" in startup commands so devices can be seen by Windows:

Yeah I guess it's something with ISP's router.

I will look into this. Is that an option on OpenBeken? Currently at work, can't check it, will look into later

It's a SSDP driver. You can start it from autoexec.bat or a short startup command.