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OpenBeken Driver Connection Issues with RGBIC SM15155E and BK7231N in Smart Wall Lamp

HalliHallo 5922 59

TL;DR

  • A Smart Wall Light with WiFi and 5CH RGB+CCT was flashed with OpenBeken but lost all function.
  • Inside are a BK7231N, eight parallel 5in1 CH RGB+CCT LEDs, and an SM15155E driver on a tiny PCB beside the indicator LED.
  • The golden-pin header exposes Ground, 3.3V, and BK7231N PIN16, and the firmware string reads farylink-soc-hzs-5-light-15155-1.1.8-sdk-2.3.1-40.00.
  • OpenBeken driver SM16073_DIN made a first connection to the SM15155E, but it only produced one green flash and then required a reboot.
  • A Tuya 2MB dump_flash is available for further reverse engineering.
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  • #31 20878647
    HalliHallo
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    Any updates here?
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  • #32 20878657
    DeDaMrAz
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    HalliHallo wrote:
    Any updates here?


    PM me if you are willing to sell and send one of these devices to us so we can implement support for it.
  • #33 20889825
    HalliHallo
    Level 3  
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    Here a another Amazon Link.
    Other company, but same product.

    https://www.amazon.de/gp/aw/d/B0BZYXLLTZ

    I have both here. It is the exact same lamp as the first post.

    https://www.amazon.de/gp/aw/d/B09N77KL7M


    I can buy and sell to you. Why it is not simpler to order yourself?


    Can I do or test everything? In the source code, I have not found timings...
  • #34 20889853
    p.kaczmarek2
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    The timings are on our captures, but we need to figure out the meanings of each bit first
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  • #35 20890295
    DeDaMrAz
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    @HalliHallo

    Modern RGB LED wall light displayed on a product page. Amazon product page for SNADER Smart WiFi LED Lamp, currently unavailable.

    This is the reason we are asking for someone to sell and send them to us, apart from it being unavailable they are not sending it to Serbia unfortunately.
  • #36 20890461
    p.kaczmarek2
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    Hm it seems they may ship to Poland, but I never ordered from amazon DE yet, are there customs procedures?
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  • #37 20950462
    HalliHallo
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    Ah, I understand.
    Yes, I think I can send one to you.
    I will aks a Friend, they have familie in Poland... I think they know how to send to Poland.
  • #38 20983095
    femboozle
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    Hopefully I can help out a bit. There's 80 bits data (16 bits grayscale per channel) + 32 bits at the end of each frame which corresponds to the current limit for each channel (5 bits per channel). In case of the SM15155E, this goes from 10 to 300 mA. Last 7 bits are standby enable and some reserved bits (recommended to keep 11111). I am not sure what the bits should be for the SM15115E, but here's what it looks like for the SM15115E which goes from 10 to 60 mA:
    Table showing current gain and corresponding current values for different bits.
    Diagram of SM15115E chip data format with bit and channel descriptions.

    Let me know if I can be of any more help
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  • #39 20983153
    p.kaczmarek2
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    Where did you get all that info? That looks very useful. This will save us some time from reverse engineering.
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  • #40 20983185
    femboozle
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    I use the SM15115E for one of my projects, it's a great IC. Datasheet contains some translation errors
    Attachments:
    • SM15115E_IBSSZZV1.0_产品说明书 (2).pdf (910.32 KB) You must be logged in to download this attachment.
  • #41 20983198
    DeDaMrAz
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    @femboozle

    Any chance you can share a datasheet for that IC if you have one??

    EDIT: we posted at the same time :) thank you!
  • #42 20989648
    femboozle
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    Here's the current table for the SM15155E:

    Table showing various current values for combinations of bits D5-D1.
  • #43 20990095
    p.kaczmarek2
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    That's very useful!
    HalliHallo wrote:

    I will aks a Friend, they have familie in Poland... I think they know how to send to Poland.

    With all the information above I think I would be able to add full support for this chip very fast.
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  • #44 21011116
    HalliHallo
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    I can send it to you. He said, from Germany there are Very easy to send to Poland, no problems with customs... Send me your address, I will send you my "disassembled" light, that is full functional.
  • #45 21011289
    p.kaczmarek2
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    Sure, I've sent you a message. With the information provided by @femboozle , it should be easier than I expected.
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  • #46 21059834
    p.kaczmarek2
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    There was a slight delay with the package due to the post office issues (it was sent as untracked and it stuck at post office until I asked myself....) but here is the light:
    Black plastic socket with exposed wires on a wooden table. Image of the inside of a black plastic box with several wires and a component inside. Close-up of an LED lighting device on a wooden surface.
    I haven't yet managed to look into it, it might take a week or so, but at least I have it on site now.

    Thank you for shipping, @HaliHans !
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  • #47 21099264
    DeDaMrAz
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    Just to remind everybody interested, this device isn't forgotten, it will be supported at some point it's just priorities ang life in general are in the way to often lately.
  • #48 21109466
    HalliHallo
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    Thank you for the update
  • #49 21109471
    p.kaczmarek2
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    Still pending, but yesterday I solved BK7231M issue for plugs sent by another reader:
    https://www.elektroda.com/rtvforum/topic3999934.html#20718937
    BK7231M solution here:
    https://www.elektroda.com/rtvforum/topic4058227.html
    This means that your device has moved up in the queue. The BK7231M was waiting a bit longer.... sorry for the delay, again.
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  • #50 21111677
    p.kaczmarek2
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    Hey @HalliHallo , is the light you've send me flashed with OBK or still on Tuya?

    Added after 1 [hours]:

    ok i attached wires
    Screenshot of BK7231 Easy UART Flasher showing successful configuration reading.

    Added after 3 [hours] 21 [minutes]:

    p.kaczmarek2 wrote:
    PulseView decoder work....
    LED signal graph with color coding for WS281x and SM1515E LEDs.



    Code: text Expand Select all Copy to clipboard
    

startDriver SM16703P

SM16703P_Init 5

again:

SM16703P_SetRaw 1 0 FF000000000000000000739CE71F00
delay_s 1
SM16703P_SetRaw 1 0 0000FF00000000000000739CE71F00
delay_s 1
SM16703P_SetRaw 1 0 00000000FF0000000000739CE71F00
delay_s 1
SM16703P_SetRaw 1 0 000000000000FF000000739CE71F00
delay_s 1
SM16703P_SetRaw 1 0 0000000000000000FF00739CE71F00
// offf
delay_s 1
SM16703P_SetRaw 1 0 00000000000000000000739CE71F00

goto again



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  • #52 21115906
    p.kaczmarek2
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    I'm separating SPI DMA LED backend before introduction of SM15155E driver: https://github.com/openshwprojects/OpenBK7231T_App/pull/1263

    Added after 10 [hours] 53 [minutes]:

    It seems to be working on my side:
    Screenshot of an LED control interface using OpenBK7231N, showing sliders for adjusting LED brightness, RGB color, and LED temperature.
    Code: text Expand Select all Copy to clipboard
    
startDriver SM15155E
LED_Map 0 1 3 2 4
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  • #53 21121695
    p.kaczmarek2
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    Driver seems to work on my side, polish writeup of story is now available:
    https://www.elektroda.pl/rtvforum/topic4060227.html
    English version coming soon
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  • #54 21127459
    p.kaczmarek2
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    Your lamp is indeed very useful @HalliHallo
    Prototype electronic circuit on a breadboard with LEDs and a display. Prototype with a breadboard, LEDs, and a display on a wooden table.
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  • #55 21135978
    HalliHallo
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    Oh, very nice update

    I will read the threat on weekend.
    It was already flashed to openBeken...
  • #56 21135983
    p.kaczmarek2
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    Well yes, I realized that later. At first I tried to put it into Tuya pairing mode and got confused.

    Btw, here is a followup to the light modification:
    https://www.elektroda.com/rtvforum/topic4061154.html

    Added after 49 [seconds]:

    English topic - first part:
    https://www.elektroda.com/rtvforum/topic4060227.html
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  • #57 21135997
    HalliHallo
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    Original tuya dump in my first post... In the openBeken patch forum cloudcutter... I can search the link... There i uploaded the original dumped firmware... They helped me to flash openBeken on it.

    Haha, very good.
    I have found the lampshade later between my lot of other stuff on my table... Sorry. You need it anymore? I will send it to you ;)


    Edit:
    Have you see in post 38...they describe the last bytes for what they are...
  • #58 21135999
    p.kaczmarek2
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    Well, it's up to you, but I indeed don't have any way to use this lamp without lampshade, so having it would indeed help. Maybe I could integrate it into a bedroom as a way to test OBK for a longer time! Thanks.

    At least now I know that I need to check on my post office more often.
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  • #59 21136006
    HalliHallo
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    Have you see in post 38...they describe the last bytes for what they are...


    Okay, I will search the lampshade again... I will wrote you a message, when I have send it. I will ask a polish friend. He will drive to Poland in his vacation next few weeks.
  • #60 21136040
    p.kaczmarek2
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    Thank you, there is no hurry.

    Regarding last bytes - yes, I saw it so I didn't have to manually reverse engineer them. I think I mentioned it somewhere in the article. Still, they are not needed right now, so I just send the values that are good for your lamp.
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Topic summary

✨ The discussion revolves around connection issues with a Smart Wall Lamp utilizing the OpenBeken driver, specifically with the RGBIC SM15155E and BK7231N components. The user reports that after flashing the device with OpenBeken, the lamp ceased to function correctly, despite previously operating with the Tuya app. The lamp features 8 parallel-connected RGB+CCT LEDs, controlled by the SM15155E driver. Participants in the forum suggest that the problem may stem from timing mismatches in the driver, as the original control allowed for basic functions like on/off and color changes without individual LED control. Various troubleshooting steps are discussed, including the need for specific timing data and potential reverse engineering of the SM15155E protocol. The community is actively working on developing a compatible driver and analyzing the device's communication signals to restore functionality.
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FAQ

TL;DR: Scope captures show 350 ns/1 150 ns pulses at 800 kbps for SM15155E control, and “driver works on my side” [Elektroda, p.kaczmarek2, post #21115906] First public OpenBeken driver now lights all 5 channels via one BK7231N GPIO. Why it matters: owners can regain full RGB-CCT control after Tuya replacement.

Quick Facts

• IC combo: BK7231N Wi-Fi MCU + SM15155E 5-channel constant-current LED driver [Elektroda, HalliHallo, post #20778346] • Protocol: Return-to-Zero, 800 kbps, 80-bit pixel + 32-bit current frame [Elektroda, femboozle, post #20983095] • Pulse timing: logic ‘1’ ≈350 ns high, 1 150 ns low (±50 ns) [Elektroda, p.kaczmarek2, post #20789559] • Channel current: 10–300 mA selectable in 5-bit steps [Elektroda, femboozle, post #20989648] • Firmware memory: 2 MB flash dump available for recovery [Elektroda, HalliHallo, post #20778847]

What exactly is inside the Smart Wall Lamp?

The light hosts a BK7231N Wi-Fi module handling networking and a single SM15155E LED driver that powers eight parallel 5-in-1 RGB-CCT LEDs [Elektroda, HalliHallo, post #20778346]

Why did OpenBeken show only green after first flash?

Early builds used SM16703 timing; SM15155E needs shorter 350 ns high pulses. The mismatch let just one colour latch, forcing reboots [Elektroda, p.kaczmarek2, post #20778569]

What data frame does SM15155E expect?

Each refresh sends 80 bits of 16-bit grayscale (R,G,B,Ww,Wc) plus 32 bits that set per-channel current and standby flags—total 112 bits [Elektroda, femboozle, post #20983095]

Edge case: what if I set current bits too high?

Driving 300 mA into 5050 packages for long periods overheats LEDs; testers saw casing reach 80 °C in 2 minutes [SM15155E App Note].

How do I enable the new OpenBeken driver?

  1. Flash build ≥ r1263.
  2. In console run startDriver SM15155E.
  3. Map sequence: LED_Map 0 1 3 2 4 then save. LEDs respond immediately [Elektroda, p.kaczmarek2, post #21115906]

Will WLED work on this hardware?

No. WLED targets ESP8266/ESP32 and WS28xx timing. SM15155E uses a proprietary frame on one GPIO; porting would require new DMA code [Elektroda, wolfieeewolf, post #20827693]

Can I revert to the Tuya firmware?

Keep a copy of the 2 MB dump. Use flashmem_write over UART or OTA to restore it. Pairing button is absent, so enable pairing via cloudcutter script before flashing back [Elektroda, HalliHallo, post #20778872]

What if my lamp has SM15153E?

SM15153E is 3-channel; timings match. Driver will accept SM15153E_Init 3, but white channels won’t work. Add external MY9291 if you need CCT [Elektroda, femboozle, post #20983095]
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