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Shelly 3EM-63 Gen3

State: untested Generation: 3 Chip: ESP32-C3

Gen3 / ESP32-C3.

Fact Value
Profile S3EMG3
Flash 8 MB
Official package 2.1.0
Partition table 0x10000
App slot size 0x280000

Before you start

Check first:

  • the device runs Shelly's own firmware, not ESPHome yet
  • you know its IP address (--ip), or this PC is on the device's own access point (default 192.168.33.1)
  • the device can reach this PC: same network, port 8000 (--port) not blocked
  • your ESPHome config uses the partition table below and is compiled
  • a UART adapter is at hand as your way back (Recovery over UART)

ESPHome config

Important

build refuses a config without Shelly's partition table. Copy partitions/S3EMG3-stock.csv from this repository next to your YAML and keep CONFIG_PARTITION_TABLE_OFFSET: "0x10000".

esp32:
  variant: ESP32C3
  board: esp32-c3-devkitm-1
  flash_size: 8MB
  partitions: S3EMG3-stock.csv        # copy from partitions/ in this repository
  framework:
    type: esp-idf
    sdkconfig_options:
      CONFIG_PARTITION_TABLE_OFFSET: "0x10000"
    advanced:
      enable_ota_rollback: false

ota:
  - platform: esphome
    allow_partition_access: true

Flash it

  1. Install the requirements (once):
pip install -r requirements.txt
  1. Fetch the official package:
python ota.py fetch S3EMG3 --insecure
  1. Build: put your app into it; the ZIP goes to out/:
python ota.py build S3EMG3 app.ota.bin --esphome-factory app.factory.bin --esphome-yaml app.yaml
  1. Check the device first. Nothing is sent:
python ota.py send S3EMG3 out/S3EMG3-app-<date>.zip --ip <device IP> --dry-run
  1. Flash it and watch the log:
python ota.py send S3EMG3 out/S3EMG3-app-<date>.zip --ip <device IP> --watch 120

app.ota.bin and app.factory.bin are the two files ESPHome compiles. --dry-run only checks the device and, for this package, reads the update target slot. Command reference: Commands.

What to expect

In the --watch log look for these lines, in this order:

# Log line Meaning
1 Update target slot: 0 ... The slot check of send. Anything else: run python ota.py restore S3EMG3 first
2 Boot: cur ... min ... update? 1 The installer will write ESPHome's bootloader. update? 0 means it will not: build again with a higher --boot-min-version (why)
3 ota_progress up to 95 %, then ota_success The device restarts into ESPHome

Notes for this device

No device-specific findings yet. Please report the --watch log, especially the lines Update target slot, Boot: cur ... update? and Will write to slot.

The profile sets boot_min_version: "1.0.9": devices of this family run Shelly's loader 1.0.3, which would otherwise skip ESPHome's bootloader (update? 0).

Way back

python ota.py restore S3EMG3 sends the official firmware back while Shelly firmware still runs.


Warning

  • Wipes Wi-Fi and settings. ESPHome opens its own access point or joins the Wi-Fi from your config; if nothing comes up, power-cycle the device (help).
  • No way back over the network once ESPHome's bootloader runs: restore gets no answer, only UART brings Shelly OS back (Recovery over UART). Take a flash backup first if you can.
  • Flashed it? Tell us, also when it worked: open a device report.