LabKit ESP32 Firmware

Arduino firmware for the ESP32 DevKit-C. Turns a cheap dev board into a browser-controlled hardware debug tool — GPIO, I2C, SPI, UART, and analog — with an on-device web UI and WebSocket console.

Current release: v1.0 · On-device version: 1.0

Flash in browser
Product page	labkit.app/apps/devkit-c
Platform	labkit.app

No toolchain required to flash — use Chrome or Edge, connect the board over USB, and click Flash.

---

Features

• On-device web UI — configure pins, run bus transactions, and monitor state from the browser
• WebSocket console — real-time serial bridge between the browser and UART
• I2C — bus scan, register read/write, device discovery
• SPI — configurable transfers via the web interface
• UART — baud-rate control and message passthrough
• GPIO & analog — pin direction, digital I/O, and analog reads (DevKit target)
• WiFi provisioning — credentials stored in flash; connect via UART command or the web UI

---

Hardware

Item	Detail
Target board	ESP32 DevKit-C (4 MB flash)
Board define	ESP32DEVKIT in board_define.h
Default I2C	SDA 21, SCL 22
Default UART1	RX 17, TX 16
USB	Required for flashing and serial console

---

Flash firmware

Option A — Browser (recommended)

Click the badge above or open the LabKit release page. Connect your ESP32 over USB and flash — no Arduino IDE or esptool needed.

Works on Chrome and Edge (Windows, macOS, Linux).

Option B — Build from source

1. Install Arduino IDE 2 with the ESP32 board package.
2. Install libraries: ArduinoJson, ESP Async WebServer, Async TCP.
3. Open labkit_esp32.ino.
4. Confirm board_define.h has #define ESP32DEVKIT.
5. Select board ESP32 Dev Module (4 MB flash, default partition scheme).
6. Upload via USB.

Or compile with arduino-cli:

arduino-cli compile \
  --fqbn esp32:esp32:esp32:FlashSize=4M,PartitionScheme=default,FlashMode=qio,FlashFreq=80 \
  --output-dir build \
  labkit_esp32

Build artifacts (build/, *.bin, *.elf, *.map) are gitignored.

---

First run

1. Flash the firmware and open the serial monitor (115200 baud).
2. Connect to WiFi — send over serial:

   wifi <ssid> <password>
   

   Credentials are saved to flash and reused on boot.
3. When connected, the serial output prints the device IP. Open http://<ip> in a browser to use the on-device UI.

Scan for nearby networks:

wifi scan

---

Project layout

File / folder	Purpose
labkit_esp32.ino	Main sketch — setup, WiFi, HTTP/WebSocket server
Config.h	Version string, feature flags, buffer sizes
board_define.h	Hardware target selection (ESP32DEVKIT)
index_html.h	Bundled on-device web UI
*Manager.*	I2C, SPI, pin, and error handling modules
WebSocketCommandHandler.*	WebSocket protocol and commands
JsonResponseBuilder.*	JSON API responses
CommandHandlers.*	UART and command dispatch

---

Branches & releases

Branch / tag	Purpose
main	Production line — tagged releases only
develop	Active firmware development
v1.0	Initial public source release

---

Related

• LabKit platform — github.com/labkitapp
• Release docs — labkit.app/releases/docs (sharing links, embed widgets, README badges)

---

Contributing

Contributions are welcome. See CONTRIBUTING.md for the fork → PR workflow. Open pull requests against develop, not main.

---

License

This firmware is licensed under the MIT License.

Copyright © 2026 LabKit