It appears to be a Lightning Electronics LN8825B chip, which has no mention on this forum or any other, that I can find. It seems no chance it's a rebranded version of something we can flash. The same situation as https://www.elektroda.pl/rtvforum/topic3989796.html
Do you have a multimeter to check what might have been damaged? Maybe at least MOSFETs are okay and they can be reused after making a ESP12 transplant.
I do have a multimeter but not sure I have the patience to work out what is wrong with it when theyre so cheap :s
BUT
There is still no sign of it for detection in any Tuya app or any new device in AP mode, but I seem to be getting something from the TX0/RX0 pins if I use the 12v DC adaptor. I cannot seem to get a baud rate that produces a clean output though
I've tried CH340 and PL serial adaptors. The CH340 doesn't seem to register any output at all. I'm not sure my external 3.3v is pushing enough current because I only get the log out when using a DC jack.
I'm off home for Christmas now so won't be able to do anything more for a week or so. I could order another one too in case I have half-killed this one
I've now managed to flash an LN8825B over UART using an official flasher GUI. You have to pull A10 down. I scratched the trace for A10 on this same LED controller as there are no A10 pads. Perhaps expectedly, LN882H OBK does not boot.
$ ./build.sh build mcu_no_os_xip_sample
argv[0]:./build.sh
argv[1]:build
mkdir build
-- The C compiler identification is GNU 11.3.0
-- The ASM compiler identification is GNU
-- Found assembler: /usr/bin/cc
-- The CXX compiler identification is GNU 11.3.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- PROJECT:wifi_mcu_develop
-- CMAKE_SOUECE_DIR:/cygdrive/w/GIT/ln882x-mcu
-- Building project:firmware_XIP
-- Build type: Debug
CMake Error at CMakeLists.txt:35 (include):
include could not find requested file:
/cygdrive/w/GIT/ln882x-mcu/project/wifi_mcu_develop/gcc/gcc-arm-none-eabi.cmake
CMake Error at CMakeLists.txt:36 (include):
include could not find requested file:
/cygdrive/w/GIT/ln882x-mcu/project/wifi_mcu_develop/gcc/target-def.cmake
CMake Error at CMakeLists.txt:43 (include):
include could not find requested file:
/cygdrive/w/GIT/ln882x-mcu/project/wifi_mcu_develop/gcc/gcc-flags.cmake
CMake Error at CMakeLists.txt:59 (add_subdirectory):
add_subdirectory given source
"/cygdrive/w/GIT/ln882x-mcu/components/net/lwip-2.0.3/src" which is not an
existing directory.
CMake Error at CMakeLists.txt:60 (add_subdirectory):
add_subdirectory given source
"/cygdrive/w/GIT/ln882x-mcu/components/net/iperf" which is not an existing
directory.
CMake Error at CMakeLists.txt:61 (add_subdirectory):
add_subdirectory given source
"/cygdrive/w/GIT/ln882x-mcu/components/net/ping" which is not an existing
directory.
CMake Error at CMakeLists.txt:62 (add_subdirectory):
add_subdirectory given source
"/cygdrive/w/GIT/ln882x-mcu/components/net/dhcpd" which is not an existing
directory.
CMake Error at CMakeLists.txt:63 (add_subdirectory):
add_subdirectory given source
"/cygdrive/w/GIT/ln882x-mcu/components/kernel" which is not an existing
directory.
CMake Error at CMakeLists.txt:64 (add_subdirectory):
add_subdirectory given source "/cygdrive/w/GIT/ln882x-mcu/components/fs/kv"
which is not an existing directory.
CMake Error at CMakeLists.txt:65 (add_subdirectory):
add_subdirectory given source
"/cygdrive/w/GIT/ln882x-mcu/components/fs/nvds" which is not an existing
directory.
CMake Error at CMakeLists.txt:66 (add_subdirectory):
add_subdirectory given source
"/cygdrive/w/GIT/ln882x-mcu/components/fs/partition_mgr" which is not an
existing directory.
CMake Error at CMakeLists.txt:67 (add_subdirectory):
add_subdirectory given source "/cygdrive/w/GIT/ln882x-mcu/components/atcmd"
which is not an existing directory.
CMake Error at CMakeLists.txt:68 (add_subdirectory):
add_subdirectory given source "/cygdrive/w/GIT/ln882x-mcu/components/wifi"
which is not an existing directory.
CMake Error at CMakeLists.txt:69 (add_subdirectory):
add_subdirectory given source "/cygdrive/w/GIT/ln882x-mcu/components/fota"
which is not an existing directory.
CMake Error at CMakeLists.txt:70 (add_subdirectory):
add_subdirectory given source
"/cygdrive/w/GIT/ln882x-mcu/project/wifi_mcu_develop" which is not an
existing directory.
-- Configuring incomplete, errors occurred!
See also "/cygdrive/w/GIT/ln882x-mcu/build/CMakeFiles/CMakeOutput.log".
ready to flash whatever can be made. I'm trying to find a test/demo bin of something else to flash to be sure this chip still works. I've flashed back the factory dump of this device taken using jlink, but it doesn't seem to be booting. LN8825B is the device you have too.
Still, I don't see LN8825B in use much. The LN engineer says they only ship dev boards to China but they did link to this product
no, LN8825B cannot be flashed with the LN882H flasher
Added after 41 [minutes]:
actually, there was no need to reveal A10 trace. There is of course a test pad for A10
Added after 39 [minutes]:
don't know what's in these bins but some are definitely booting. there are a few LN8825x firmwares in the Lightning Semi FTP dumps
The RF test bins do boot. I can tell RF is active because my PSU only registers enough current in use when RF is active. The bin "flashimage-connection_ln8825_20201019.bin" is the only one I've seen a uart log output for so far
At least I know my chip can boot and RF probably works. Haven't seen any visible SSIDs though
from the same company - My Quick Links - MQLinks - who are selling the LN882H MQ-12F on Taobao, here are some more resources for their older LN8825B modules
not that there's much to be gained from it, apart from the experience doing it, I've bought some of these QFN32 .5 pitch boards to transplant the LN8825B chip from the LED controller onto. I'll post success/failure in due course! Wish me luck
The Heruled Tuya WiFi Smart LED Controller is based on the Lightning Semiconductor LN8825B chip, which is relatively undocumented and unsupported in common forums. Initial attempts to identify or flash the device failed due to lack of SDK and boot log access, possibly caused by reversed power polarity damaging the unit. Subsequent efforts revealed partial UART boot logs indicating a Tuya RTOS SDK dated 2020, suggesting similarity to the LN882x family, including the LN882H WiFi&BLE combo chip. Attempts to flash LN882H firmware onto LN8825B devices were unsuccessful, confirming incompatibility. Official LN8825B flashing tools and firmware dumps from Lightning Semiconductor FTP were found, with some RF test binaries booting and producing UART output, though no visible WiFi SSIDs appeared. Resources and firmware for LN8825B modules MOL100D0 and MOL100P0 were shared, including AT command firmware enabling UART interaction. Hardware transplant experiments involve desoldering the LN8825B QFN32 chip for prototyping, requiring a 40 MHz crystal oscillator and proper power supply decoupling with 100nF capacitors on multiple 3.3V power pins (VDD33, VDDA33, VIO1, VIO2). Pinouts differ from LN882H modules, complicating direct hardware swaps. Community members are exploring SDKs from Lightning Semiconductor's gitee repository and other sources, though some links are dead or restricted. Overall, the LN8825B chip remains challenging for custom firmware development and hardware hacking, but progress is ongoing with shared firmware dumps, flashing tools, and hardware reverse engineering. Summary generated by the language model.
