Next Steps After Teardown for TUYA Cloud Cutter Pull Request on LEDVANCE Bulb

Well, first you need a 2MB flash dump and then you can submit it for them to add profile. I can submit it myself, can you share 2MB backup here?
We can also use it to extract OBK config.

Hi P.!
Piotr? or Patryk?


Hm, I realize I´m really old fashioned: feels somehow strange to me talking to someone without knowing his name....

In any case, thank you for your answer !

Now, according to this description I hope I could figure out the soldering tips correctly (see pics below), but I am not sure whether to use RX/TX 1 or 2: do you have any idea?

gramais

I think you may have got it right at the first try. Regarding the UART port - well, you should check our YT channel for detailed flashing process presentations:
https://www.youtube.com/@elektrodacom
You can also check our flash tool docs/readme:
https://github.com/openshwprojects/BK7231GUIFlashTool
But to answer your question, always UART 1 (RX1/TX1) port is used for flashing. The UART2 is used for debug log output.

Just please, remember to make 2MB backup first, so first do "read" operation, not "write"!

Okay, so I started the first attempt - unfortunately without success :(

I double-checked everything and swapped RX/TX to be on the safe side, but maybe you could take another look: the photos are below.

I tried it via PINs 8=TX, 10=RX, 17=3V3, 25=GND of the GPIO port (/dev/ttyAMA0) and alternatively via a USB-UART converter (/dev/ttyUSB0).


resp.

or

resp.


The program waits indefinitely for a response via the GPIO port:



Via USB I get this error message:



I interrupted the 3V3 again and again to achieve a reset.

Any ideas? Do you notice anything wrong with the wiring in the photos?



Added after 2 [minutes]:

... and before you ask: I have no access to a windows computer for the GUI, just a RaspberryPi and Mac with the same results shown above.

Hi, how did you remove the bottom screw without breaking the glass?
Is the stock tuya firmware patched?

How do you power it, how long are the wires, what kind of USB to UART converter? Have you tried swapping RX and TX?

Hey @ferbulous, I heated the socket with a heat gun until I could simply twist it off...

I had imagined it would be more difficult, but then it went very easily.

:)

And as for the firmware patch: no idea, how do I find out?

Added after 11 [minutes]:

Hi @p.kaczmarek2

what do you mean by

p.kaczmarek2 wrote:

How do you power it,

else than the above described converters or GPIO 3V3 PIN I used?

And for:

p.kaczmarek2 wrote:

how long are the wires

They are about 30-40cm long.

The

p.kaczmarek2 wrote:

kind of USB to UART converter?

is this one here.

And last, yes, I have

p.kaczmarek2 wrote:

tried swapping RX and TX?

as described above.

Those wires seem very long. Futhermore, your USB to UART converter does not look like the one that can provide enough current for flashing. Use a better 3.3V source and shorten your wires. Have you watched our tutorials?

Okay, so now that I'm back, I'm going to clear up my two open posts. I've already successfully got the door and window sensor working (complete and corrected instructions will follow soon) and now I'd like to free this light bulb from the cloud using CloudCutter.

I've now dismantled a second one and soldered it cleanly again, but I still couldn't establish a connection for a firmware backup.
😭

Now I've come across this post about a similar bulb that also uses the WBLC5 MCU. This post confirms my setup and PIN selection, but the author writes about the same difficulties I'm having:

Quote:

I tried to do it so many times that the TX pad from the module's PCB broke off from various attempts.

However, he goes on to say that he was able to find a solution with a tip from you, @p.kaczmarek2:

Quote:

Help came from @p.kaczmarek2 (Thx!) . He suggested to try to upload at a higher speed than 115000 and use a 100pF capacitor between 3.3V and GND at the output of the voltage stabilizer. I

Could you please explain to me in simple terms exactly where I need to attach the 100pF capacitor to establish the connection?
Where do I find the voltage stabilizer and its output?

Or is there perhaps a purchase recommendation for a UART-to-USB converter that already contains such a capacitor?

Or maybe @Dark Man could help explaining to me how / where exactly you soldered the capacitor to the UART-converter? Would be really kind - thank you ❤️

Hmm I am not sure how I can be more specific, there is only single 3.3V and GND line in the circuit. Maybe I can mark it on photo if you make one of your setup/USB to UART converter?

If you are using a breadboard setup with separate 3.3V LDO like I often do, then there is no need to solder, you can just insert capacitor in the breadboard slots.

Usually it also helps to make connection lines shorter.

>>21650941

Okay, cool, I’ll make a pic of the two different boards I used - thank you!

I've looked into the Darkman's topic you mentioned, so, there is relatively good explanation, however you can still improve some things:
- use shorter wires
- you can also use a better 3.3V power supply, some people even take 3.3V from Arduino board. I am personally using a breadboard with AMS1117-3.3V clone (TC1264 in my case). This is because, those tiny USB to UART converters don't have good enough current capability at 3.3V.

Added after 2 [minutes]:

You can see my flashing setup there: https://www.youtube.com/@elektrodacom

>>21651100

OK, so - just to get this right - when using an external 3.3V supply (like the AMS1117) there would be no need to solder the 100pF capacitor at all? Or could it help for even better chances additionally?

Well, to be precise, it's 100nF, I assume, not 100pF. That pF is probably a mistake on Darkman's side. Still, the value is not critical and should be on board already.
Sample circuit:

>>21651380

So, these are the two USB-UART adapters I have: from a technical point of view, one looks better than the other. I'm sure you've already gained some experience: or is one the same as the other?




And finally, my AMS1117. But I'm not sure why there are two codes on each side:



104 = 100nF and (at the same time?)
106 = 10 µF

Can that be right?