< [Configuration guide](configuration.md) | [Index](../README.md) | [Known issues](known_issues.md) > # Flashing guide ## 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 lamp and your computer. ## Opening the lamp, to expose the PCB Remove the rubber pads from the botton of the lamp, to get access to 4 screws that attach the bottom to the rest of the lamp. Note that you don't have to remove these pads fully. Once you can access the screws, you've gone far enough. Unbolt the 4 screws which were hidden under the rubber pads. Detach the bottom from the rest of the lamp, exposing the PCB. This might take a bit of force. Just pull it off bit by bit, until it pops loose. ## Solder the wires The wires will be connected to the debug pads that are shown in the following image. Many of the serial to USB adapter have some header pins to which you can connect the wires of a device. Therefore, it might be useful to take some dupont wires, cut off one end, and solder the stripped end to the board. TODO Solder the wires to the `RX`, `TX`, `GND` and `GPIO0` debug pads that are shown in the following 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 adapter 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 lamp, `GPIO0` must be connected to ground while the lamp boots up. Therefore, connect these wires *before* plugging in the lamp's power supply. Flashing will not work if you connect these wires after the lamp has already been booted 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 lamp's 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 lamp's power supply. After booting up, you can release the button (the serial console will also mention that flash mode is now enabled). 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 (a third hand would be very welcome with this), but it can be done. - You could opt for temporarily soldering a lead between `GND` and `GPIO0` on the board, making `GPIO0` pulled to ground permanently. It is a bit less flexible than some other options, but if you only need to do the initial backup and firmware flash of the lamp, then this can be all that you need. Remove the lead after flashing is done, otherwise the lamp won't boot in normal mode. ## Make a backup of the current firmware Backing up the firmware makes it possible to revert to the original firmware, in case you have problems with the ESPHome firmware. The backup can be created using "esptool". Installation instructures can be found here: https://github.com/espressif/esptool/blob/master/README.md#installation--dependencies Here's an example on how to backup the original firmware from Linux. First, unplug your lamp's power supply, then start the esptool read_flash command: ``` python esptool.py -p /dev/ttyUSB0 read_flash 0x0 0x400000 original-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`. Now plug in the power supply. The output of esptool should now show that it connects to the lamp and downloads the firmware from it. **Caution**: You will find the WLAN SSID and Password of the last used WiFi network in this file. Therefore, keep this backup in a safe place. ## Restore the backed up firmware In case you need to rollback to the lamp's original firmware at some point, here's an example of how to restore the original firmware from Windows, by fully flashing it back onto the lamp. First, unplug your lamp's power supply, then start the esptool write_flash command: ``` python.exe .\esptool.py --chip esp32 --port COM3 --baud 115200 write_flash 0x00 original-firmware.bin ``` Make sure that `GPIO0` is connected to GND and plug in the power supply. The output of esptool should now show that it connects to the lamp and uploads the firmware to it. Be patient after the upload reaches 100%. The output is silent for a while, but esptool tool is verifying if the firmware was uploaded correctly. After the firmware upload completes, unplug the power, disconnect `GPIO0` from GND and reconnect the power supply to boot into the restored firmware. ## Flash new ESPHome firmware Setup an ESPHome Project (see [README.md](../README.md)),compile the firmware for the lamp and download the `firmware.bin` file to the device to which the serial adapter is connected. You can flash the lamp using esphome or esptool. I would recommend using the [esphome-flasher](https://github.com/esphome/esphome-flasher) tool, which is a very easy to use GUI utility app for flashing ESPHome devices: - In the app, select the COM port of your serial adapter. - Also select the firmware.bin file to flash onto the lamp. - Power up the lamp with `GPIO0` connected to GND. - Click the "Flash ESP" button to flash the firmware. If you want to flash with esptool, you can use: ``` python.exe .\esptool.py --chip esp32 --port COM3 --baud 115200 write_flash 0x1000 ``` After flashing, power down the lamp, disconnect `GPIO0` from GND and reconnect the power to boot into the new ESPHome firmware. From here on, it is possible to flash the lamp OTA (over the air, which means that the firmware is uploaded over WiFi) from ESPHome. Therefore, it is now time to tuck away or remove those soldered wires 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 lamp'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 lamp 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 *Note: 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) < [Configuration guide](configuration.md) | [Index](../README.md) | [Known issues](known_issues.md) >