Codex skills for ESP32 and Arduino
These skills treat a microcontroller project as a device that has to recover with nobody at the bench. Codex builds ESP-IDF, Arduino and PlatformIO firmware from the command line with pinned cores and platforms, keeps ISR work short, sizes FreeRTOS stacks from measured watermarks, and designs OTA updates with two slots and rollback so a bad image falls back to working firmware.
Start with these 3
- ESP32 Firmware Reconnect, sleep and update without a cable Codex treats an ESP32 project as a device that must recover alone: Wi-Fi is event-driven with reconnect, deep sleep is measured on the battery lead, partitions include two OTA slots with rollback, and every panic is decoded against an archived ELF. It also knows which strapping and flash pins to keep away from.
- Arduino Sketches Sketches that run for weeks, not minutes Codex builds Arduino sketches from the command line with pinned cores and libraries, restructures blocking delay() code into rollover-safe millis() tasks, guards ISR-shared variables, and keeps strings out of SRAM on AVR boards. Hardware bugs get a symptom table and an I2C scan before anyone rewrites a driver.
- Firmware OTA Updates Updates that cannot brick the device Codex designs OTA so a bad image, power cut or dropped download always falls back to working firmware: two slots, signatures checked by the bootloader, confirmation only after real health checks, and anti-rollback counters for security fixes. A bundled script builds and verifies release manifests, and rollouts move in stages that halt on rollback spikes.
General skills with ESP32 and Arduino guidance
Not built around ESP32 and Arduino, but they include steps or tools for it. Not part of the install-all command.
Every ESP32 and Arduino skill in one command
Installs these 6 into ~/.agents/skills/. Add --project after -- to install into the current repository instead.
The installer is a 104-line POSIX shell script. It fetches the skills you name from codexskills.dev and unpacks each into its own folder in your skills directory. No sudo, no telemetry, and every skill page shows the full SKILL.md first. Read install.sh
curl -fsSL codexskills.dev/install.sh | sh -s -- esp32-firmware arduino-sketches firmware-ota platformio micropython freertos ESP32 and Arduino FAQ
Is there a Codex skill for ESP-IDF on the ESP32?
Yes. ESP32 Firmware targets ESP-IDF 5.x or the Arduino-ESP32 3.x core and records the chip and IDF version with idf.py --version before changing anything. It covers event-driven Wi-Fi reconnect, NVS, deep sleep, a custom partition table with two OTA slots and app rollback enabled, and decoding panics with addr2line against the archived ELF. It also warns about strapping pins such as GPIO12, which selects 1.8 V flash when high at boot and stops most modules from booting.
Can Codex build Arduino sketches without the Arduino IDE?
Arduino Sketches works entirely through arduino-cli: it finds the port and FQBN with arduino-cli board list, compiles with --warnings all, and pins cores and libraries in sketch.yaml profiles. It rewrites blocking delay() code into rollover-safe millis() timers, wraps literal strings in F() to keep them out of SRAM on AVR boards, and marks ESP32 interrupt handlers IRAM_ATTR. For larger projects, PlatformIO pins exact platform versions in platformio.ini and unit-tests logic in a native environment with Unity.
How do these skills handle firmware OTA updates safely?
Firmware OTA Updates designs A/B slots so a bad image, power cut or dropped download falls back to working firmware, using ESP-IDF rollback with Secure Boot v2 on the ESP32 and MCUboot on Zephyr and other Cortex-M targets. Images are signed with imgtool or espsecure, and the skill treats a signing key stored in the repo as already compromised. Its bundled ota_manifest.py creates and verifies release manifests and refuses a downgrade below the device's version or security counter, though it does not sign anything itself.
How do I install all 6 ESP32 and Arduino skills at once?
Pass every name to the installer in one command: curl -fsSL https://codexskills.dev/install.sh | sh -s -- esp32-firmware arduino-sketches firmware-ota platformio micropython freertos. Add --project right after -- to put them in the current repository's .agents/skills/ so your team gets them too.
Which ESP32 and Arduino skill should I try first?
ESP32 Firmware is the closest fit for most ESP32 and Arduino work. Mention it with $esp32-firmware in a prompt to load it on purpose; after that, Codex picks it up on its own whenever a task matches.