I recently brought a couple of smart bulbs, which can ben controlled with your smartphone using a specific app.
The bulbs are RGBW, i.e. they have the ability to emit different colors (RGB) in addition to the cold white color (W) and are branded Fcmila:
I wasn’t able to find the official website of the manufacturer, but only its store on Aliexpress.
Unlike other bulbs I brought in the past, these use the Cloud Intelligence application
it’s therefore not possible to use tuya-convert to install an alternative firmware and control them with other domotic applications/hubs (for example the great Home Assistant).
Some users (like blakadder) were able to replace the control module of the bulb with one based on the ESP8266 chip. I want to verify if it would be possible to do the same also with my bulb.
I started opening the bulb by removing the diffuser. It is sufficient to remove the glue with a hobby knife and it comes off easily, revealing a printed circuit (labeled RC-6253) with white LEDs on the outside and RGB ones on the inside:
I then removed the white silicone that holds the PCB anchored to the bulb case and managed to remove it:
The PCB carrying the LEDs is connected to the control board via a 6-pin connector. The board is instead connected with two wires to the E27 connector of the bulb. I had to cut them to be able to work more easily on the board:
The board consists of two PCBs mounted at 90°. The main one shows the wording www.ada.top and has the task of transforming the mains voltage (230V) into a voltage suitable for powering the logic circuits (3.3V) and for the LEDs. The board mounted at 90° seems to mount a microcontroller for the management of the light bulb and for communication (WiFi / BLE):
I removed the solder with a solder wick and I was able to separate the two boards:
The microprocessor is labelled OPL1000. Searching on the Internet, you can find that it is manufactured by a chinese company, Opulinks, and that an SDK is also available to develop applications. Unfotunately, at the moment I wasn’t able to find any firmwares (like Tasmota) that was ported for this microcontroller.
The meaning of the first 4 pins was obvious: I therefore soldered some wires and tried to connect the module to an USB-Serial adapter to verify it it was possible to establish a serial communication:
Unfortunately, even chaning parameters and sending characters, I wasn’t able to receive anything from the module. It is possible that the running firmware doesn’t send output on the serial port or that a specific init sequence should be sent to activate it. Please let me know in the comments if you were able to communicate with this module.
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