From 7c3ee035d8a524d3822de8b2e019f9317a9d98b4 Mon Sep 17 00:00:00 2001 From: Maurice Makaay Date: Thu, 8 Apr 2021 22:29:04 +0200 Subject: [PATCH] Update FLASHING.md A few updates to the flashing docs. --- doc/FLASHING.md | 62 ++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 51 insertions(+), 11 deletions(-) diff --git a/doc/FLASHING.md b/doc/FLASHING.md index ffd9a37..56bae48 100644 --- a/doc/FLASHING.md +++ b/doc/FLASHING.md @@ -86,12 +86,22 @@ to find another way to attach GPIO0 to ground. Some options: 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. +- 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 device, then this can bee all that you + need. Remove the lead after flashing is done, otherwise the device won't + boot in normal mode. + ## Download and install esptool See: https://github.com/espressif/esptool/blob/master/README.md#installation--dependencies ## Make a backup of the current firmware +Here's an example on how to backup the original firmware from Linux. First, +unplug your device's power supply, then start the esptool read_flash command: + ``` python esptool.py -p /dev/ttyUSB0 read_flash 0x0 0x400000 original-yeelight-firmware.bin ``` @@ -100,30 +110,60 @@ python esptool.py -p /dev/ttyUSB0 read_flash 0x0 0x400000 original-yeelight-firm 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 device and downloads the firmware from it. + **Caution**: You will find the WLAN SSID and Password of the latest used WiFi in -this file. +this file. Therefore, keep this backup in a safe place. -**After each step with esptool, you have to unplug you power line and connect it again.** +## Restore the backed up firmware + +In case you need to rollback to the device'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 device. + +First, unplug your device's power supply, then start the esptool write_flash command: + +``` +python.exe .\esptool.py --chip esp32 --port COM3 --baud 115200 write_flash 0x00 original-yeelight-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 device 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 was uploaded, unplug the power, disconnect GPIO0 from GND and +reconnect the power to boot into the restored firmware. ## Flash new firmware Setup an ESPHome Project, see [README.md](../README.md) +Compile the firmware for the device and download the `firmware.bin` file +to the device to which the serial adapter is connected. 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. +tool, which is a very easy to use GUI utility app for flashing ESPHome devices: -If you want to flash with esptool, compile with esphome and download the -generated firmware. +- In the app, select the COM port of your serial adapter +- Also select the firmware.bin file to flash onto the device +- Power up the device 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 +python.exe .\esptool.py --chip esp32 --port COM3 --baud 115200 write_flash 0x1000 ``` -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. +After flashing, power down the device, disconnect GPIO0 from GND and reconnect +the power to boot into the ESPHome firmware. + +From here on, it is possible to flash the device 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 @@ -143,7 +183,7 @@ python esptool.py --chip esp32 -p /dev/ttyUSB0 --baud 115200 --before default_r 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. +*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)