Flashing LSC Smart GU10-RGB Bulb with OpenBK7231T: Overload Issue with USB->Serial Converter

Last week I was able to tear down a LSC Smart GU10-RGB bulb.
My idea was to flash the chip with OpenBK7231T

But, the issue is, that when I connect the LSC PCB to GND and 3V3 (coming from the USB->Serial converter), the USB converter starts to "Hiccup" (like an overloaded switched power supply). This is already the case when I only connect GND and 3V3, for this I used the point labeled GND and 3V3 on the PCB.

The 3V3 from the USB->Serial converter can supply 50mA so this should be sufficient (I have flashed LSC smart sockets with this).
In an attempt to "Isolate" the BK7231 I have removed the Schottky diode coming from the built-in power supply and the 470uF capacitor.

Any help is welcome. It is a "Virgin device", I did not try an OTA flash (yet).

Well, I can see you already have taken good steps towards fixing the issue (removing the capacitor and the diode), but it seems the problem still persists.
This is why I always recommend using external reliable LDO.
Take a look at my setup here:

NOTE: the circuit above assumes you have desoldered WiFi module, but it's basically the same if you just connect 3.3V LDO to the power on the board.
Image source: https://www.youtube.com/watch?v=7MyfSgxLAOo&ab_channel=elektroda.pl

The BK7231 at peak activity can take more than 50mA. I would never attempt to use such weak LDO. You must have lucked out with previous devices.

Find any better 3.3V supply (maybe from Arduino? But it's a bit hacky) or just a 3.3V LDO, maybe AMS1117-3.3V (very cheap, can be also found on scrap boards) and try again.

EDIT: Look, for example, this user also reports that he needed a better power supply: https://www.elektroda.com/rtvforum/topic3937358.html

Hi, I got also some of that GU10 from Action. I got two different versions. Both with firmware 2.9.16 and both flashed with tuya-cloudcutter with the profil is added for this bulb. Also the configuration is the same with sm2135 on pin 24 SM2135DAT and 26 SM2135CLK.
The difference is the barcode on the package and then the mapping in openbeken for the bulbs.

This is with SM2135_Map 1 2 0 4 3



and this is with SM2135_Map 1 0 2 4 3
Also added only flag 4 and 8.
When I use flag 9 I can't toogle the light to off or on cause colour is always on.
Hope this will help others with this GU10.

Thank you, I will add this config to templates database. By the way, here is a flag list, because most of the people don't remember what is what:

So you're saying you're using flag 8? Are you sure that it matters for this device? I think that it will also work without flag 8.

I cheked it, and no matter with flag 8.

There is a new version at Action Stores Version 1.1 with firmware 2.9.6. I dumped it and added it to tuyacloudcutter Profile to flash OTA.


There are 5 PWM.
Pin 7 = channel 5 is warm white,
Pin 8 = channel 1 is red,
Pin 9 = channel 2 is green,
Pin 24 = channel 3 is blue
Pin 26 = channel 4 and cold white.
Like I wrote before seems to be a new version.

alfakenzo wrote:

There is a new version at Action Stores Version 1.1

Is it a Gu10 version as well? Can you show more photos of the packaging?

Here are some more of them.

Hi everyone,
Just wanted to confirm a working config for this bulb and use this chance for a BIG BIG THANKS for this project. Before I was just jealousy looking at the huge selection of the much cheaper tuya devices that I couldn't flash with tasmota... now after a steep learning curve flashing over the air works even faster and much more convenient than with tasmota - just awesome!

Bought above GU10 bulb today at Action and the package has the barcode ending on 409 (as on the picture above)
My config:
- Flags: 4, 8, 10, 12, 16
- Startup: all channels -1 (together with flag 12 this makes the bulb power up in the last state)
- Startup command text: SM2135_Map 1 2 0 4 3
- Module config: P24 - SM2135DAT, P26 - SM2135CLK

During setup I encountered an issue (guess due to sloppiness) that I wanted to share in case someone runs into the same:
No matter what device map I configured both sliders (tone and brightness) did pretty random things, moving them a bit could change the color or brightness or tone on the same slider and the rgb picker did nothing at all Eventually I found out that at some point I used SM2235 everywhere instead of SM2135... small but significant difference.

After sorting that out the bulb is now happily integrated and works great!

.

Hi there, got two of these bulbs in my drawer as spares and I had to use it yesterday.
The reference is now 3004919.1 on the package, FW 2.9.29 on BK7231T.

I convert using TCC and the main difference is that this bulb is using now SM2235 instead of SM2135.
I'm using this conf and everything is working fine :



edit : I'm also using flags 4 & 8.

For your info, Action FR is now selling those bulbs by pack of 3 for 12€, I bought one yesterday, REF 3208076 but unfortunately, it seems to be an BK7231N on FW 1.5.32, known as a patched one so no big chance with those bulbs. I will use them on local tuya.

snakesrules94 wrote:

For your info, Action FR is now selling those bulbs by pack of 3 for 12€, I bought one yesterday, REF 3208076 but unfortunately, it seems to be an BK7231N on FW 1.5.32, known as a patched one so no big chance with those bulbs. I will use them on local tuya.

Hi, Yesterday I bought two in Action IT and unfortunately there is firmware 1.5.32 ;
I'm desperately looking for GU10 bulbs to use with DDP RGBW protocol

more and more devices are patched, maybe we should focus on figuring out the way to flash LEDs via UART without damaging them...

>>21350542
Unfortunately I'm not very familiar with opening light bulbs and I would like to take a lot of them for the whole house

You could try checking another, maybe smaller, Action shop. They still may have older batch.

tech1977 wrote:

snakesrules94 wrote:

For your info, Action FR is now selling those bulbs by pack of 3 for 12€, I bought one yesterday, REF 3208076 but unfortunately, it seems to be an BK7231N on FW 1.5.32, known as a patched one so no big chance with those bulbs. I will use them on local tuya.

Hi, Yesterday I bought two in Action IT and unfortunately there is firmware 1.5.32 ;
I'm desperately looking for GU10 bulbs to use with DDP RGBW protocol

Hello, also in Action France, they are now selling revision 3004919.2 version of the GU10 bulb with 1.5.32 FW. I guess the only chance to use it is with Tuya / Local Tuya. The implementation is not as free as you could have with OBK FW but it works.

>>21359868
Hi, unfortunately I want to use GU10 with DDP protocol so I need OBK or WLED firmware.
I'm looking for more GU10 bulbs

I have bought also recently 2x3 gu10 leds (pack), hard to open* and different then here, no flash points found yet. 4 have firmware 1.5.32 and two 2.9.6 the last two has less dim and more brightness than 1.5.32. In tuya cloud they have different icons as well, 4 has the e27 and 2 have the glass gu10 version displayed.

*can't get whole chip out due to the 230v connection.

I’ve got the same issue, there is WIFI module type - CBLC5 (BK7231N) mounted, with programming pads on the rear part.


The connection point and module type is described in topic https://www.elektroda.com/rtvforum/topic3951016.html

The first try was unsuccessful - the TX1/RX1 was quite fragile and has been torn off by the wire after soldering.
[url=https://obrazki.elektroda.pl/9062130600_1745185030.jpg]

Trying also with my favourite "spider" tool ..



Tomorrow second bulb ...Second try..