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Nous A8M Smart Plug Tuya T34 BK7231N OpenBeken Flashing Experience & Power Data Delay

meav33 885 4
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  • #1 21701101
    meav33
    Level 3  
    Posts: 4
    I purchased some Nous A8M smart plugs because they advertised matter support and I thought that would make it easy to integrate them into HA without flashing them.

    However I discovered that the matter implementation is very bad (power measurements are delayed by up to 30minutes)


    So I opened up one plug to see if it can be flashed

    Nous A8M Smart Plug Tuya T34 BK7231N OpenBeken Flashing Experience & Power Data DelayNous A8M Smart Plug Tuya T34 BK7231N OpenBeken Flashing Experience & Power Data DelayNous A8M Smart Plug Tuya T34 BK7231N OpenBeken Flashing Experience & Power Data DelayNous A8M Smart Plug Tuya T34 BK7231N OpenBeken Flashing Experience & Power Data Delay


    It uses a Tuya T34 chip based on BK7231N and sadly does not expose any programming pads.
    However with a lot of patience I was able to solder some very small wires to the chip and flash it with open Beken.

    The device chips with a special 3.0 bootloader, to get the ota feature to work i flashed an old 1.01 bootloader.

    Sadly it does not quite work correctly:
    I can control the relay and get power measurements. As long as the device is already plugged in while the plug boots.

    However when I plug something into the plug, the the firmware immediately reboots and the WiFi led flashes.
    In the stock firmware everything works fine.

    The generated openBK config is as follows:

    Device configuration, as extracted from Tuya:
    - BL0937 SEL on P14
    - Button (channel 1) on P7
    - BL0937 VI (CF1) on P26
    - WiFi LED on P8
    - BL0937 ELE (CF) on P24
    - Relay (channel 1) on P6
    Device seems to be using T34 module, which is using BK7231N.
    And the Tuya section starts at UNCOMMON POSITION 2052096


    Code: JSON
    Log in, to see the code



    Does someone have an idea what might be the issue?
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  • #2 21701126
    p.kaczmarek2
    Moderator Smart Home
    Posts: 14416
    Help: 650
    Rate: 12371
    Does the reboot happen if you use OBK with clear config (no relay, led, power measurement) driver?

    Does the reboot happen if you enable PowerSave? PowerSave 1
    Helpful post? Buy me a coffee.
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  • #3 21701161
    meav33
    Level 3  
    Posts: 4
    >>21701126

    I think it was not a software issue.
    I disassembled and reassembled the smartplug and now it no longer reboots when I plug something in it.
    Maybe something was wrongly oriented inside the first time?
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  • #4 21701191
    p.kaczmarek2
    Moderator Smart Home
    Posts: 14416
    Help: 650
    Rate: 12371
    Maybe something was shorting VDD to ground.
    Helpful post? Buy me a coffee.
  • #5 21701791
    divadiow
    Level 38  
    Posts: 4859
    Help: 424
    Rate: 860
    this doesn't help with your situation but here's the boot log from the backup you posted elsewhere. I thought v3 bootloader warranted the post

    Code: Text
    Log in, to see the code
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