Flashing Issues with LSC Light Bulbs Model 2578539.2 Using BK7231 UART Flasher

Question

Hey guys, I just bought 3 LSC light bulbs and honestly, I didn't check the reference.
So that's the 2578539.2 model, firmware 1.5.32

For some reason I can't flash it with bk7231 easy uart flasher. (Getting bus failed)

Anyone have encountered this problem?
My uart converter is working properly with some other device but not this model.
Seems like there is no power going to the chip?

plekke · Accepted Answer

>>21244245 check my schematic, what worked very good m/999GUqv.pngAdded after 19 [minutes]:esphome: name: lscrgbcct friendly_name: LscRGBCCTbk72xx: board: generic-bk7231n-qfn32-tuyathis is my header and this code; there is a bp5758d leddriver inside

p.kaczmarek2 · Answer

Maybe wrong pins? Isn't U1_TX where I pointed the arrow?

mattistiret1 · Answer

I'll try that soon and let you know

p.kaczmarek2 · Answer

How it looks from the other side? Maybe we can look at the traces to double check which are UART1.

mattistiret1 · Answer

There you go :) Added after 47 [minutes]:That doesn't work either

mattistiret1 · Answer

>>21287571
Hi! This wiring is working but, I had to unplug the 3.3V cable.
I'm not powering it to flash them and it works like a charm

The pinout you gave me isn't working by the way here is what I got from reading the config from tuya firmware (also not working) :

Log in, to see the code

plekke · Answer

indeed, the chip is BP5768, and the esphome library is written for BP5758

i also did not find the difference in i²c protocols....

on the bk-chip, i²c clk is pin 24, and i²c data is pin 26

i added the pinout in the image

p.kaczmarek2 · Answer

Is there any documentation of BP5768 protocol? I can add BP5768 support to OBK if it's needed. I've only found that, a very short chinese datasheet:

mattistiret1 · Answer

Hi everyone So I had to read the pinout from another bulb. I copied this pinout to all the other bulbs (same ones) and now it works like a charm

plekke · Answer

>>21305839 hello, what do u mean? i traced out the pcb, and had: i²c clk is pin 24, and i²c data is pin 26

mattistiret1 · Answer

Using been writer software, I read the pinout and copied it to the bulb once I flashed openbeken

spicydiet_0o · Answer

It's been a while, but have you been able to secure the firmware? I'd like to use cloud cutter for the lights, but I need to create a profile...

gehaxelt · Answer

Hi there,

just got one of these bulbs, too (article no: 2578539.2). Managed to dump the firmware and extract the config with bk7231tools:


{
   "2235ccur": 14,
   "2235wcur": 6,
   "Jsonver": "1.1.9",
   "brightmax": 100,
   "brightmin": 5,
   "cagt": 20,
   "category": "0505",
   "cmod": "rgbcw",
   "colormax": 100,
   "colormin": 10,
   "colorpfun": 1,
   "crc": 72,
   "cwmaxp": 100,
   "cwtype": 0,
   "defbright": 100,
   "defcolor": "c",
   "deftemp": 100,
   "dmod": 8,
   "gmkb": 60,
   "gmkg": 60,
   "gmkr": 80,
   "gmwb": 75,
   "gmwg": 70,
   "gmwr": 100,
   "iicb": 0,
   "iicc": 4,
   "iicg": 1,
   "iicr": 2,
   "iicscl": 24,
   "iicsda": 9,
   "iicw": 3,
   "module": "CBU",
   "notdisturb": 0,
   "onoffmode": 1,
   "pairt": 600,
   "pmemory": 1,
   "prodagain": 0,
   "remdmode": 1,
   "rgbt": 15,
   "rstbr": 50,
   "rstcor": "c",
   "rstnum": 5,
   "rsttemp": 100,
   "title20": 1,
   "wfcfg": "spcl",
   "wfct": 10,
   "wt": 20
}

Unfortunately, after importing it through the Web UI, it does not appear to work (bulb does not turn on):


ClearIO // clear old GPIO/channels
lfs_format // clear LFS
StartupCommand ""  // clear STARTUP
stopDriver *  // kill drivers
startDriver SM2235 // so we have led_map available
setPinRole 9 SM2235DAT
setPinRole 24 SM2235CLK
LED_Map 2 1 0 4 3

Any ideas what to do?

EDIT: The chip on the LED-pane is a "BP5768D", so maybe the detected driver "SM2235" is not correct? Using the GPIO-Finder and setting all pins (relay-mode) to high won't light up the bulb at all. How can I help debug?

divadiow · Answer

Please post your Tuya firmware backup

gehaxelt · Answer

Here is the full 2MB flash dump.

divadiow · Answer

try importing this then rebooting Code: JSONLog in, to see the code

gehaxelt · Answer

Thank you, but this does seem to change anything. I tried your and the 9/24 pin configuration, but no luck.

I'll try to take pictures of the PCB traces and maybe reflash the original firmware to see if I accidentally broke something.... or are there other things I can do?

p.kaczmarek2 · Answer

Do you reboot after setting config? Can you see the LED driver running on the main page? Please provide some photos of the PCB.

gehaxelt · Answer

Yes, I issued a reboot through the Web UI button. I have just retested using physical power on/off reboots, but no change. EDIT: Yes, the driver(s) are running according to the main page. My assumption was that maybe the wrong pins/channels are set? Here are the images of the PCB:

divadiow · Answer

OK. I see where 9, 24 comes from

Log in, to see the code

so re-reading past experiences above it seems @Matistreet got their 2578539.2 with BP5768D working fully? in OBK?

Yours is a 2576539.2 with BP5768D so the expectation is that the OBK BP5758D driver is OK on BP5768D.

Added after 14 [minutes]:

>>21412670

@spicydiet_0o if your device is the 2578539.2 with firmware version 1.5.2, the same posted here https://www.elektroda.com/rtvforum/topic4078301.html#21425425

then a cloudcutter profile will not be possible. 1.5.2 / 3.3.42 BUILD AT:2023_09_05_15_44_43 is on the known patched list https://github.com/tuya-cloudcutter/tuya-cloudcutter/wiki/Known-Patched-Firmware

gehaxelt · Answer

Double checked the numbers again and found a mistake. I have a 2578539.2 as well, sorry. So yes, I would expect it to work, too, but it won't right now.

divadiow · Answer

ah OK, sure. Maybe flash back to factory to be sure?

Added after 14 [minutes]:

interesting (maybe) that there's mention of kp18058 and sm2135 in your firmware but no mention of bp57xx

Added after 5 [minutes]:

could try kp18058 driver just in case?

gehaxelt · Answer

You're totally right (had a look at the app.bin, too), but it still does not work. How reliable is the GPIO pin extraction? Could it be that I'm configuring the wrong pins? Setting all pins to HIGH in the web UI does not result in the bulb lighting up. I'll reflash the original firmware on the weekend...

Thanks for all the help so far

p.kaczmarek2 · Answer

Do you reboot after every pin change, so the driver starts with new config?

gehaxelt wrote:
Setting all pins to HIGH in the web UI does not result in the bulb lighting up.

The so-called I2C drivers will not light up LED if you set all pins to High. It's not PWM - it requires a transaction that follows a specific protocol.

gehaxelt · Answer

Ah, alright - understood! I thought I did "reboot" the whole device with the big red button for every test, but I'll redo them again just in case I overlooked something.

Let's assume I flash the original image - can I somehow verify the pin settings with a multimeter or would I need an oscilloscope (which I don't have)?

divadiow · Answer

interesting observation, new to me anyway, - BP57X8D seem to be grouped so I guess the same driver can be used, as evidenced by the experience of the OP Added after 1 [minutes]: continuity with the multi-meter even before flashing to factory?

gehaxelt · Answer

Hi again, spent a bit of time trying to flash back the original firmware. Is there a trick to it with openbeken already flashed? It seems like I can't get the chip into flash mode (power on/off or cen methods) - it just boots into openbeken? Can I flash the full original dump from the web UI?

p.kaczmarek2 · Answer

It should just work as usual. You can reboot even without CEN, just through OBK restart button.

gehaxelt · Answer

You were right and I have some good news! Using my little DSO138 oscilloscope, I managed to identify the PINs used in the original firmware. These correspond to Pin 7 + 8 in OBK, so with a bit of trial and error I identified the right configuration to make this light bulb work:


ClearIO // clear old GPIO/channels
lfs_format // clear LFS
StartupCommand ""  // clear STARTUP
stopDriver *  // kill drivers
startDriver BP5758D // so we have led_map available
setPinRole 7 BP5758D_DAT
setPinRole 8 BP5758D_CLK
//BP5758D_Current 14 6 // according to the extractor, but I use lower values for less heat
BP5758D_Current 10 5
BP5758D_Map 0 1 2 3 4

Here's my importable config:


{
  "vendor": "Action",
  "bDetailed": "0",
  "name": "LSC Smart Connect LED Smart Lightbulb A60 E27 RGB (WiFi)",
  "model": "ArtNo. 2578539.2",
  "chip": "BK7231N",
  "board": "CBU",
  "flags": "1024",
  "keywords": [
    "Action LCS",
    "Lightbulb",
    "BK7231N",
    "CBU",
    "OpenBeken"
  ],
  "pins": {
    "7": "BP5758D_DAT;0",
    "8": "BP5758D_CLK;0"
  },
  "command": "backlog BP5758D_Current 14 6; BP5758D_Map 0 1 2 3 4; Dimmer 50;",
  "image": "https://obrazki.elektroda.pl/8091289800_1738784599.jpg",
  "wiki": "https://www.elektroda.com/rtvforum/topic4078301.html"
}

The LED map had also to be changed. Can we somehow fix the bktools extractor to find the correct driver and pins?

Approach	What the thread found	Practical result
BK7231 UART flashing	Works when wiring is corrected and the adapter's 3.3V lead is removed	Successful flashing reported
Tuya config extraction only	Reported `iicscl 24` and `iicsda 9` with SM2235	Wrong for this bulb batch
OpenBeken with verified pins	`BP5758D`, pins `7/8`, map `0 1 2 3 4`	Bulb worked
Tuya CloudCutter	Firmware `1.5.2 / 3.3.42` listed as patched	Not suitable for profile-based cloud flashing

Flashing Issues with LSC Light Bulbs Model 2578539.2 Using BK7231 UART Flasher

How can I flash an LSC light bulb model 2578539.2 with BK7231 Easy UART Flasher when it returns "bus failed"?

Topic summary

FAQ

Quick Facts

Why does the BK7231 Easy UART Flasher show a "bus failed" error when flashing an LSC Light Bulb 2578539.2 with firmware 1.5.32?

How do I correctly wire and power an LSC 2578539.2 bulb for BK7231 UART flashing if applying 3.3V from the adapter prevents flashing?

Which UART TX/RX pads are the correct ones on the LSC Smart Connect bulb model 2578539.2, and how can PCB traces help confirm them?

What OpenBeken configuration finally worked for the LSC Smart Connect LED bulb 2578539.2 with BK7231N and BP5768D?

How can I find the real LED driver pins on an LSC 2578539.2 bulb when Tuya config extraction reports the wrong GPIOs?

What's the difference between BP5758D and BP5768D LED drivers, and why does the BP5758D driver appear to work on a BP5768D bulb?

When Tuya firmware extraction shows iicscl 24 and iicsda 9, why might the bulb actually work only with pins 7 and 8 in OpenBeken?

How do I use bk7231tools dissect_dump to extract Tuya user_param_key data from a full flash dump of an LSC light bulb?

What is OpenBeken, and how is it used on BK7231N-based smart bulbs like the LSC 2578539.2?

What is Tuya CloudCutter, and why is firmware 1.5.2 / 3.3.42 considered patched and unusable for profile-based cloud flashing?

How should I set up BP5758D_Map and BP5758D_Current for an LSC RGB+CCT bulb so the color channels and white channels work correctly?

UART flashing vs Tuya CloudCutter for LSC BK7231 bulbs — which approach makes sense when the installed firmware is patched?

Why doesn't setting all GPIO pins HIGH in the OpenBeken web UI light up a bulb that uses an I2C-style LED driver such as BP5758D or BP5768D?

What tools can I use to verify LED driver communication pins on a smart bulb PCB — multimeter continuity checking, a simple oscilloscope like DSO138, or something else?

How do I restore the original Tuya firmware to a BK7231N bulb after flashing OpenBeken, and what should I do if the chip seems to boot straight back into OBK?