Backing up / restoring Shelly firmware before flashing ESPhome / Tamsota?

ESPHome
1

I got some Shellys running well but want to experiment with some new Gen4 ones.
If i flash Esphome, is there a way to revert back to original Shelly firmware?

The only info i found was:

  • Getting the original firmware from shelly.
    For the newer Generation i did not find any and i also read somewhere you cant restore if the data partition with mac adress (or something similiar) is overwritten.
  • Backing up the original firmware beforehand.
    The infos using the esptool for this date to older shellys with less RAM.

Do you have any experience with reverting firmware on ESP modules?
Thanx

2

Hi,
The availability of stock Shelly firmware appears to be patchy. I had to buy a second Shelly EM to dump the firmware out to restore another device back from Tasmota.

sudo dnf install esptool
# https://github.com/bglnelissen/shelly_flash
esptool.py --port /dev/ttyUSB2 read_flash 0x00000 0x200000 ./shelly-dump.bin


# shellyem SHEM
# https://kb.shelly.cloud/knowledge-base/shelly-em
# http://archive.shelly-tools.de/
# http://firmware.shelly.cloud/gen1/SHEM.zip

# restore
esptool.py --port /dev/ttyUSB0 erase_flash
esptool.py --port /dev/ttyUSB0 write_flash 0x00000 shelly-dump.bin

After restoring the firmware, I had to perform a factory reset as the restored device booted with a duplicate MAC and DeviceID.

FYI, Tasmota on a Shelly EM works, but without calibration data, it gives odd readings at low power. Restoring to Shelly stock firmware gives Power & Energy (not voltage & current) which HA seems to prefer for the Energy Sankey diagram.

If this helps, :heart: this post!

1 Like
3

Oh, and for a hardware serial interface to make Shelly firmware changes simpler, my weapon of choice is a Tasmotizer PCB from RevK:

He designs nice hardware tools, sells them cheaply, and they work well.

Without one, you need something like a generic USB serial board, and fiddle with Cat5 cable cores as jumper wires as the Shelly programming sockets are not 0.1" pitch.

4

Thanks for your replies.
It points in the same direction already researched.

About the hardware serial flashing… this makes the task even harder.
I somehow flashed a shelly years back and even build a pin construction for that. So far i was not able to reproduce my succes. The cable might be loosing contact and my uart flashers lacks a 2nd GND for connecting GPIO0.

So your advice for the RevK kit looks useful but seems hard to get .
The VoltLink programmer offers a cable for flashing shellys but would cost me 30 Euros in Germany. I might try a bit longer low level before investing :wink:

5

The fine-pitch female connector does fit solid core wire, so a “standard” USB to serial board worked for my first attempts. An offcut of Cat5e worked fine as jumper wires.

6

I got to backup my Shelly firmware (via the windows GUI esp flash download tool).
I had to solder an additional GND pin at my usb serial flasher.
With GPIO 0 connected to ground the ESP started in flash mode and backing up and flashing ESPhome was possible :wink: