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- # Flashing the Yeelight Bedside Lamp 2
-
- ## Tools needed
-
- * Allen key (2mm, 5/64") or torx (T8) screw driver
- * Soldering Iron
- * Perhaps some sticky tape
- * A serial to USB adapter (FTDI)
- * Some wires
-
- ## Warning
-
- We have writen these instructions with care, but we will give absolutely no
- warranty. Perhaps you will destroy your device and your computer.
-
- ## Opening the Yeelight
-
- Remove the rubber pads from the botton of the device.
-
- Unbolt the 4 screws which were hidden by the rubber pads.
-
- 
-
- Remove the bottom from the device, exposing the PCB.
- This might take a bit of force. Just pull it up bit by bit until it pops loose.
-
- For some good picture of disassembling this device, take a look
- [at this blog post](https://mysku.ru/blog/china-stores/78455.html)
- It is in Russian, but the translation by Google works well and moreover, the
- pictures are the most important thing here. If you scroll down, you will
- find them easily.
-
- ## Solder the wires
-
- Many of the serial to USB adapter have some header pins to which you can
- connect the wires of a device. Therefore, I find it most useful to take some
- dupont wires with a female end to them, and cut off the other end. Strip the
- wire on the other and, and then it can be used to solder it to the board.
-
- Solder the wires to the RX, TX, GND and GPIO0 debug pads that are shown in this
- photo. It is not required to solder a wire to the 3.3V debug pad. This pad
- is not directly connected to the 3.3V Vin of the ESP32 chip, making it a
- less than optimal candidate for powering the board during flashing. Instead,
- powering the lamp using its own power supply works best.
-
- 
-
- You can use some sticky tape to fixate the cables before soldering.
-
- ## Connect the wires to your serial to USB device
-
- The wires must be connected as follows:
-
- | Soldering point| Serial USB Adapter name |
- | -------------- |:------------------------:|
- | GND | GND |
- | TX | RX |
- | RX | TX |
- | GPIO0 | GND |
-
- To be able to flash the device, GPIO0 must be connected to ground while the
- device is booted. Therefore, connect these wires before plugging in the
- device's power adapter. Flashing will not work if you connect these wires
- when the device has already been powered up.
-
- ## When you only have one GND pin on your USB Adapter
-
- If your USB Adapter does not have multiple GND pins, then you'll have
- to find another way to attach GPIO0 to ground. Some options:
-
- - Use a breadbord, so you can connect the USB Adapter GND pin to a row on
- the bread bord, and connect the GND and GPIO0 wires of the board to that
- same row.
-
- - Solder a button on the board that connects GPIO0 to GND when pressed. Then
- you can hold down this button while plugging in the device's power supply.
- After booting up, you can release the button (the serial console will also
- mention that the device is now in flash mode). This is not the most
- practical solution for most people (since only one such flash operation is
- needed, from then on OTA - Over The Air - updates are possible), but it
- was a great help to me during the initial reverse engineering and firmware
- development.
-
- - Manually hold a wire connected to both a GND surface (e.g. the silver pad
- on the left of the board) and the GPIO0 debug pad, while plugging in the
- power supply. After booting, the wire can be removed. This is very fiddly
- way of doing it, but I did it a few times and it can be done.
-
- ## Download and install esptool
-
- See: https://github.com/espressif/esptool/blob/master/README.md#installation--dependencies
-
- ## Make a backup of the current firmware
-
- ```
- python esptool.py -p /dev/ttyUSB0 read_flash 0x0 0x400000 original-yeelight-firmware.bin
- ```
-
- /dev/ttyUSB0 is the port of the usb adaper on Linux. You can find what port
- is used by the adapter by running `dmesg` after plugging in the USB device.
- On Windows this is often `COM1`, `COM2` or `COM3`.
-
- **Caution**: You will find the WLAN SSID and Password of the latest used WiFi in
- this file.
-
- **After each step with esptool, you have to unplug you power line and connect it again.**
-
- ## Flash new firmware
-
- Setup an ESPHome Project, see [README.md](../README.md)
-
- You can flash the device using esphome or esptool.
- I normally use the [esphome-flasher](https://github.com/esphome/esphome-flasher)
- tool, which is an easy to use utility app for flashing ESPHome devices.
-
- If you want to flash with esptool, compile with esphome and download the
- generated firmware.
-
- ```
- python.exe .\esptool.py --chip esp32 --port COM3 --baud 115200 write_flash 0x1000 <yourfile.bin>
- ```
-
- Once your firmware has been flashed, unplug the power and the serial USB Adapter.
- Then plug the power back in to boot the device using its new firmware.
- From here on, it is possible to flash the device OTA via ESPHOME. Tuck
- away those soldered wires in the bottom and add the bottom cover back on.
-
- ## Troubleshooting flash
-
- If you have **A fatal error occurred: MD5 of file does not match data in
- flash!**, then make sure you are powering the board using the device's own
- power adapter. We've seen these errors when trying to power the board using
- the 3.3V debug pad.
-
- After seeing this error, user @tabacha was able to successfully flash his
- device using the regular power adapter and the tasmota boot loader using
- the following command:
-
- ```
- python esptool.py --chip esp32 -p /dev/ttyUSB0 --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dout --flash_freq 40m --flash_size detect 0x1000 bootloader_dout_40m.bin 0x8000 partitions.bin 0xe000 boot_app0.bin 0x10000 ~/Downloads/schlafzimmerbedlight.bin
- ```
-
- You will find the missing tasmota boot files here:
- https://github.com/arendst/Tasmota/tree/firmware/firmware/tasmota32/ESP32_needed_files
-
- User @tabacha was not able to use tasmota with the bedside lamp 2.
-
- (remember that the [esphome-flasher](https://github.com/esphome/esphome-flasher)
- will give you a bit less of a hard-core experience during flashing)
-
-
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