micro-ota — OTA updates for MicroPython over WiFi, USB serial, and BLE, with no cloud dependency

[hicham-barhoumi]

Hi everyone 👋

I've been working on an OTA (Over-The-Air) update solution for MicroPython called micro-ota, and I wanted to share it here in case it's useful to others dealing with the same pain points.

The problem: Updating MicroPython devices in the field (or even on your desk) is tedious. You either plug in USB every time, or roll your own ad-hoc update script. Most existing solutions require a cloud service or are tied to a specific platform.

What micro-ota does

• Push code to your ESP32 in seconds over WiFi TCP, USB serial, or BLE (Nordic UART Service)
• One-command workflow: uota fast to push only your app files, uota full for everything
• No cloud dependency — works on your local network or even air-gapped via serial
• Boot guard with automatic rollback after consecutive crashes — a bad update can't permanently brick the device
• HMAC-SHA256 manifest signing so only your host can push changes
• RemoteIO side-channel to stream print() output live to your terminal and call RPC handlers on the device
• HTTP pull transport for devices that self-update from a file server on an interval
• .mpy bytecode compilation via mpy-cross built into the push workflow — cuts flash usage ~50% and boot time from 519 ms → 154 ms for the OTA module
• A VS Code extension if you prefer GUI over CLI
• Multi-device push with uota fast --all to deploy to every device on the subnet at once

Performance on ESP32 (MicroPython v1.26.1)

Metric	Value
Boot overhead (.mpy)	~252 ms (app starts in its own thread while OTA initialises in background)
OTA event loop CPU overhead at idle	< 1%
RAM footprint at runtime	~1.2 KB (0.9% of heap)

Quick start

pip install https://github.com/hicham-barhoumi/micro-ota/raw/main/releases/micro_ota-1.0.0-py3-none-any.whl
mkdir myproject && cd myproject
uota init          # creates config/ota.json, app/app.py, main.py
uota bootstrap     # first-time upload via USB
uota fast          # push your app over WiFi from now on

Repo

👉 https://github.com/hicham-barhoumi/micro-ota

It's at v1.0.0-beta, tested on ESP32 with hardware-in-the-loop tests covering all transport × operation combinations. I'd love feedback, especially from anyone using BLE or HTTP pull in production, or on boards other than ESP32.

Happy to answer questions!