logo elektroda
logo elektroda
X
logo elektroda
Advanced Search
logo elektroda

Identifying MCU on WIFIBLE Chipset Board with Erased Markings (Photos Included)

bigote 915 17
Best answers

How can I identify the MCU used on this erased-markings Wi‑Fi/BLE solar inverter board?

The MCU is most likely a Bouffalo Labs BL602-family chip, probably the BL602L20 variant, based on the internal photo showing the Buffalo/Bouffalo Labs logo and the board’s DL/download pad tracing to GPIO8 [#21779923][#21780939] An earlier guess was ESP8266EX, but the board pinout did not match that family [#21778767][#21779923] To talk to it in BLDevCube, the thread suggests making sure the chip is put into download mode via the DL pad and also trying RX/TX swapped, since some boards label pads by the destination rather than the signal [#21780939][#21780986] Even so, the OP still got “NONE”/“fail handshake,” so the exact chip was not fully confirmed in-thread [#21780939]
Generated by the language model.
ADVERTISEMENT
Report a violation of the law
Reply | New topic
  • #1 21776441
    bigote
    Level 10  
    Posts: 7
    Hi, I was wondering if anybody here knows which MCU is used on this board.
    It is a Wi-Fi/BLE chipset, but the markings have been erased on the chip.
    Here are some pics.
    Close-up of green PCB with integrated circuit, capacitors, and 26 MHz crystal oscillator
    Green PCB with labeled pins and large antenna pad on right side.
    Any help would be greatly appreciated
    AI: Do you know the brand or model number of the board, or is there any information printed on the PCB that could help identify it?
    It is manufactured by this company:
    ShenZhen Eybond Co., Ltd

    AI: Are there any other labels, numbers, or distinctive features on the board or its components that might help narrow down which MCU it uses?
    No.
  • ADVERTISEMENT
  • #2 21776532
    divadiow
    Level 38  
    Posts: 4859
    Help: 424
    Rate: 860
    don't think I'm matching it to anything in their FCC submission pics.

    Have you tried powering it to see if there are any debug logs from RX or TX?
  • #3 21777216
    bigote
    Level 10  
    Posts: 7
    Hello, and thanks for your reply. Yes, I have done that, but nothing shows up. I've tried everything from 9,600 to 115,200. I can't believe nobody has flashed this device; it comes with a whole lot solar inverters.
  • #4 21777261
    divadiow
    Level 38  
    Posts: 4859
    Help: 424
    Rate: 860
    what about the other pads? COM, or DL = debug log?

    what's the exact solar inverter make/model?
  • ADVERTISEMENT
  • #5 21777318
    bigote
    Level 10  
    Posts: 7
    Those other pads are status LEDs for the rest of the module; I wouldn't know what to do with them since I lack scope or any other equipment.
  • ADVERTISEMENT
  • #6 21778767
    piotr.ino26
    Level 11  
    Posts: 65
    Rate: 6
    If it's a datalogger from a Chinese (easun etc) inverter, it's possible it's an ESP8266EX. These loggers are rubbish straight away, they receive data every 5 min.
  • #7 21779923
    bigote
    Level 10  
    Posts: 7
    Exactly, that being the reason why I wanted to flash it with ESPHome. But the pinout doesn't match that of the many well-known MCUs. Anyways, I'm just gonna replace this module with ESP32-C and use the case which is nice to make it a Bluetooth proxy for my 4×12 V, 100 Ah LiFePO4 battery bank.
    Thanks for chiming in...

    Added after 2 [hours] 48 [minutes]:

    Ok I thing I made some progress, I found this on device report.
    It's a pdf file with pics of the internals where you can clearly see the buffalo labs logo on the chip, but the pic is not hi res to tell the actual number.
    I went on to download BLdevCube tried different chip options but always get "fail handshake" I believe it might be because the boot pin is not being activated as I don't know which pin it might be.
    Any ideas are welcome.
    thanks
    Attachments:
    • int-pic.pdf (1.89 MB) You must be logged in to download this attachment.
  • ADVERTISEMENT
  • #8 21780595
    divadiow
    Level 38  
    Posts: 4859
    Help: 424
    Rate: 860
    nice find.

    trace where IO8 goes to with multimeter?

    Wi-Fi module labeled WFBLE and pinout diagram of the BL602 QFN32 chip
  • #9 21780939
    bigote
    Level 10  
    Posts: 7
    Hello again, and sorry for the late reply, but I guess we're on different continents.
    Thanks for the help so far, I did that, and GPIO8 pin 17 goes to pad labeled DL or download I guess.
    I have it wired through 10 kΩ to 3.3 V, but sadly same result, I still get "NONE" found when I do "Read ID" on BLDevCube software.
    My board is a little bit different from the one in the PDF if you look closely, but I would still believe it IDs the same MCU.
    Don't know what else to try anymore...
  • #11 21780986
    divadiow
    Level 38  
    Posts: 4859
    Help: 424
    Rate: 860
    >>21780939

    tried swapping RX/TX round so RX->RX, TX->TX? Sometimes pads are labelled as to what they should be connected to, not what they are.
  • #12 21781776
    bigote
    Level 10  
    Posts: 7
    Sorry to disappoint you fellas. I'm giving up on this stupid little board. I've tried everything and nothing works; maybe it is a different MCU altogether, who knows.
    I've already ordered some ESP32-C3 boards; I'll just stick one in this housing and get it done with.
    Currently, I have a Pi doing the Bluetooth proxy job, but it is obviously overkill.
    Thanks to all for your efforts, but sometimes you just can't win no matter what you do, LOL...
  • #13 21781780
    divadiow
    Level 38  
    Posts: 4859
    Help: 424
    Rate: 860
    damn :( oh well
  • #14 21783336
    ajoas
    Level 2  
    Posts: 3
    I have 2 power plugs from Ali with XT-BL02 (BL602L20) BL0937 power meter. I flashed OpenBL602-Fw successfully but didn’t find a matching GPIO template, so I have to measure out by myself. Everything works fine so far except the power meter. I’m pretty sure my measuring the traces is correct, but I’ve no idea why the power meter doesn’t work. Driver is started.



    PCB board with power components and relay on a blue service mat

    Close-up of PCB with QRELAY component and uneven solder joints

    Inside of XT-BL02 plug showing PCB with electronic components and power terminals

    Close-up of BL0937 chip on green PCB with SMD components

    XT-BL02 module with resistor on power plug PCB with energy meter

    Bouffalo Lab Dev Cube screen with completed flashing process

    Close-up of USB board with IC, resistor, and connected signal wires

    Close-up of wires connected to PCB via header pins with visible solder joints

    Close-up of circuit board with connected wires and power plug contacts

    Inside of XT-BL02 smart power plug with visible PCB and power measurement components

    Close-up of label on WHZ01-WC-20A-P smart socket packaging

    Technical label on power plug device with manufacturer and certification data

    White smart plug with power button and user manual next to opened packaging
  • #15 21787175
    p.kaczmarek2
    Moderator Smart Home  
    Posts: 14416
    Help: 650
    Rate: 12371
    BL0937 should work on BL602. Are you sure you have correct pins? What do you mean by "doesn't work", does it show nothing at all, or is there a random output? Is the driver running?

    Here's idea - change the pin role from BL0937_CF to Counter, assign a free channel and observe, are the pulses seen by OBK? Is the target channel value increasing? Btw @divadiow if you have BL0937 you can also verify if it works, but I think it should. CF and CF1 pins of BL0937 are sending pulses and firmware counts them with interrupts, so Counter role should see them as well, as it is interrupt-driven.
    Helpful post? Buy me a coffee.
  • #16 21787278
    ajoas
    Level 2  
    Posts: 3
    I have 2 drivers running, NTP and the BL0937. I can see all the values but there are zeros everywhere, even the voltage. I followed the traces of CF, CF1, and SEL from BL0937 to the TX-BL02 module with the multimeter and compared it with the datasheet three times. Should be OK.
    As you mentioned, I changed the CF pin role to counter, but I don’t understand how to do that:
    “… assign a free channel and observe: are the pulses seen by OBK? Is the target channel value increasing?”
    Do you mean to check the log file on the web?

    Screenshot of interface with dropdowns and highlighted P4 field

    Power device status screen with active switch and zero energy readings
  • #17 21787499
    divadiow
    Level 38  
    Posts: 4859
    Help: 424
    Rate: 860
    p.kaczmarek2 wrote:
    Btw @divadiow if you have BL0937 you can also verify if it works, but I think it should.


    yep

    OpenBL602 interface with SM-028_V1.3 EU plug PCB showing OFF state

    red PCB EU plug with SM-028_V1.3

    Close-up of red PCB with green SM-028_V1.3 board and various mounted components.

    Code: Text
    Log in, to see the code
  • #18 21787668
    ajoas
    Level 2  
    Posts: 3
    Your PCB looks different from mine.
    It seems I have a very rare combination with BL602L20 BL0937.
    I didn’t find somebody else who flashed it already fully working, but I’m sure it’s possible.

    XT-BL02 Wi-Fi module on PCB with antenna trace and visible markings
    Wi-Fi module BL602L20 on a PCB with exposed chip and resistor



    Pin function table with names, types, and functions for 11 signal entries

    XT-BL02 module pin layout and GPIO8 working modes table


    I removed the shield with hot air to find out what controller it is.

    "4": "BL0937CF;0",
    "5": "BL0937CF1;0",
    "7": "BL0937SEL;0",
    "14": "Rel;1",
    "16": "Btn;1",
    "20": "LED_n;1"
Reply | New topic
Report a violation of the law

Topic summary

✨ A user inquired about identifying the microcontroller unit (MCU) on a WiFi/BLE chipset board manufactured by ShenZhenEybondCo.,Ltd, noting that the chip markings had been erased. The user provided photos of the board but reported no additional labels, numbers, or distinctive features on the PCB or components that could assist in MCU identification. No further responses or solutions were provided in the discussion.
Generated by the language model.
Today's popular

FAQ

TL;DR: Many Eybond Wi‑Fi/BLE datalogger boards log every 5 minutes; “These loggers are rubbish straight away.” If the chip shows a Bouffalo Lab logo, hold GPIO8 (DL) low/high during reset to enter download and try BLDevCube—otherwise consider swapping in an ESP32‑C3. [Elektroda, piotr.ino26, post #21778767] Why it matters: This FAQ helps solar‑inverter owners and tinkerers identify, flash, or replace an erased‑marking MCU without a full teardown.

Quick Facts

How can I identify the MCU when markings are erased?

Start with clues: manufacturer (Eybond), pad labels, and internal photos. Trace the pad marked DL to see if it maps to GPIO8, which hints at Bouffalo Lab parts. Try entering boot mode and reading the ID with BLDevCube. If no handshake, recheck boot wiring and serial lines. “Hold BOOT and power” is the usual pattern for Bouffalo boards. [GitHub - Opensource toolchain for Bouffalo Lab]

What does the DL pad do on this board?

On the reported board, the DL pad connects to GPIO8 (pin 17). Community testing associates that signal with the boot/download function. Pull the pad as required during reset to enter the UART downloader before using BLDevCube or bflb‑mcu‑tool. [Elektroda, bigote, post #21780939]

How do I put Bouffalo Lab BL602/BL70x into UART download mode?

How‑To:
  1. Hold the BOOT pin (GPIO8 on many BL602 boards) while applying power or tapping RESET.
  2. Release RESET with BOOT still held; then release BOOT.
  3. Connect UART, open BLDevCube/bflb‑mcu‑tool, select the chip, and click Create & Download. “Hold BOOT button down and power it” is the vendor‑recommended pattern. [GitHub - Opensource toolchain for Bouffalo Lab]

BLDevCube shows “fail handshake” or “NONE” on Read ID—what should I check?

Confirm boot mode was actually entered, that DL/BOOT is asserted correctly, and power is a steady 3.3 V. Verify TX/RX orientation and ground continuity. Try alternate USB‑UART adapters and a slower baud. If the board variant differs, pad labels may not match expected signals. [Elektroda, bigote, post #21779923]

Should I swap RX/TX even if pads are labeled?

Yes. Some boards label pads for the device they connect to, not the pad’s function. If you wired TX→RX and RX→TX and saw nothing, try TX→TX and RX→RX once. “Sometimes pads are labelled as to what they should be connected to, not what they are.” [Elektroda, divadiow, post #21780986]

Is this Eybond logger based on ESP8266 or Bouffalo Lab?

One user suspected ESP8266 in similar dataloggers, but internal photos showed a Bouffalo Lab logo on this board. That points to BL60x/BL70x families rather than Espressif. Without a readable marking or successful ID, treat it as Bouffalo‑class for boot attempts. [Elektroda, bigote, post #21779923]

Can I flash ESPHome onto this stock board?

Only if the exact MCU is supported by ESPHome and bootloader access works. In this thread, repeated attempts failed, and the owner chose to replace the module with an ESP32‑C3 while reusing the enclosure. That path is often faster and more reliable. [Elektroda, bigote, post #21781776]

Why pick an ESP32‑C3 as a drop‑in replacement?

ESP32‑C3 offers Wi‑Fi + BLE 5 (LE), 22 GPIOs, and 400 KB RAM, with strong ESPHome/Home Assistant support. It runs up to 160 MHz and has robust security features. For Bluetooth proxying and inverter logging, it’s a capable, low‑cost choice. [ESP32‑C3 Wi‑Fi & BLE 5 SoC | Espressif Systems]

What supply and interfaces should I plan for with ESP32‑C3?

Design for 3.0–3.6 V supply and 3.3 V logic. Provide UART for flashing/debug, plus optional I2C/SPI as needed. Typical receive currents are ~84–87 mA; TX peaks can exceed 275 mA, so size the regulator accordingly. [ESP32‑C3 — WIN SOURCE]

How do I capture UART logs if nothing appears at 115200?

Try all common rates from 9,600 to 115,200 bps, then 74880 or 57600 if undocumented. Power the board and watch both RX and TX. If silent, the firmware may disable logging or use a different interface. Check boot messages only after forcing boot mode. [Elektroda, divadiow, post #21776532]

What is Tuya?

Tuya is a global AIoT platform and ecosystem offering cloud services, modules, and developer tools for smart devices. Brands and OEMs use it to build, deploy, and manage connected products across many categories at scale. [About Tuya | Tuya Smart]

What is Arduino Nano?

Arduino Nano is a compact, breadboard‑friendly microcontroller board based on the ATmega328P. It mirrors Arduino Uno capabilities in a smaller form factor and programs via the Arduino IDE. It’s common for quick serial and sensor interfacing. [Arduino Nano]

What is OpenBeken?

OpenBeken is open‑source firmware, a Tasmota/ESPHome alternative, supporting chips like BK7231 and BL602. It provides MQTT, Home Assistant discovery, OTA updates, and a web UI for Tuya‑style modules. “Tasmota‑like setup” is a core goal. [OpenBeken (openshwprojects/OpenBK7231T_App)]

What is CAN bus?

CAN bus is a robust vehicle and industrial network standardized by ISO 11898. High‑speed CAN reaches up to 1 Mbit/s, while CAN‑FD increases payload and data rate after arbitration. It uses differential signaling with dominant/recessive logic. [CAN bus]

My board looks slightly different than the PDF photo—does that matter?

Yes. Small layout revisions can reroute pads or change labels. In this case, the owner noted a slightly different board while still tracing DL to GPIO8. Expect minor variants and verify with a meter before applying boot procedures. [Elektroda, bigote, post #21780939]

Any community‑tested alternatives for inverter/battery integration?

For EASUN/PIPSOLAR inverters, ESPHome components exist, and JK‑BMS integrations are available as well. These can reduce polling gaps and add local telemetry. Ensure protocol compatibility between inverter and BMS before deployment. [Elektroda, piotr.ino26, post #21780974]
Generated by the language model.
ADVERTISEMENT