ESP32 — retired

nano-ros no longer supports the ESP32. Two paths existed, and both have been removed: the ESP32-C3 bare-metal board over esp-hal, and the ESP-IDF component with its idf.py build driver. This page says what each was, why it went, and what an ESP32 port would need today.

The ESP32-C3 bare-metal board (esp-hal), retired 2026-11-02

esp32 was the ESP32-C3 under Espressif’s QEMU fork, over esp-hal: the nros-board-esp32-qemu board crate, the nros-platform-esp32-qemu platform crate and the examples/esp32-c3-baremetal/ projects. It had already been dormant: nothing built or ran it.

nano-ros supports a way of running only where it keeps its real-time promise: an executor parks until an arrival or its next deadline, and wakes for nothing else. On a bare-metal board that needs a receive interrupt and a one-shot timer behind the port’s wake object, as mps2-an385-baremetal has. The ESP32-C3 board had neither, so its executor could only poll the network. nano-ros refuses such a board rather than serve it by polling, so the board was retired instead of ported.

Every name the board answered to (esp32-c3-baremetal, esp32-qemu, esp32-c3, esp32c3, esp32) is refused with that reason wherever a board is read: system.toml, nros build, nros setup, nros::main!. The esp32 framework name is refused the same way.

The ESP-IDF component and idf.py driver, retired 2026-09

integrations/nano-ros/ was an ESP-IDF component shim. Nothing built it, it had no platform descriptor or package.xml, and it was never published to the Espressif Component Registry, so it was removed rather than kept as an untested promise.

nros build also had an idf.py driver for ESP32 boards whose package graph crossed languages. With the component gone there was nothing for a project to depend on, no ESP-IDF project for idf.py to find, and no way to carry a resolved nano-ros setting into that build, so the driver was deleted. That combination now refuses with those reasons instead of running a tool with no project to build. C and C++ on an ESP32 have no build road.

If you need an ESP32

The platform ABI and the C API are unchanged, and nothing forbids an out-of-tree port. A port has to bring what every supported board has:

• for bare metal, the network driver’s receive interrupt and a one-shot timer signalling the port’s wake object, so the session reports arrivals instead of being polled;
• for ESP-IDF, a component, a way to carry nano-ros’s resolved settings into the ESP-IDF build, and a build that something runs.

Extending nano-ros describes what a port provides.