OverWire

OverWire

Cut the cord, keep the control. OverWire is a specialized, open-source hardware bridge designed to liberate your STM32 development process. By coupling a powerful ESP32-WROOM-32 module with a dedicated SWD (Serial Wire Debug) interface, OverWire allows you to flash and debug STM32 targets completely wirelessly.

Whether your target is locked inside an enclosure, mounted on a moving robot, or just sitting across the room, OverWire brings the programming interface directly to you over Wi-Fi.

Real

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Features

• ESP32 at the Core: Powered by the robust ESP32-WROOM-32 module, providing reliable 2.4 GHz Wi-Fi and Bluetooth connectivity for Over-The-Air (OTA) target flashing.
• Dedicated SWD Port: A clean 4-pin header (3.3V, SWCLK, SWDIO, GND) ready to hook directly into your STM32 target.
• USB Type-C Interface: Modern USB-C connector backed by a CH340C USB-to-UART bridge for painless initial flashing and serial debugging of the ESP32 itself.
• Auto-Program Circuit: Features the standard dual-BSS138 (DTR/RTS) auto-reset circuit, meaning you don't need to hold down buttons to flash the ESP32.
• On-Board LDO: AMS1117-3.3V regulator safely steps down the 5V USB power to a stable 3.3V for the ESP32 and SWD target.
• Tactile Control: Includes EN and BOOT buttons for the ESP32, plus two programmable user buttons (TOP1, PROGRAM1) mapped to IO15 and IO16 for custom firmware triggers.
• Status LEDs: Two user-controllable LEDs mapped to IO12 and IO13 for quick visual feedback (e.g., Wi-Fi connected, Flashing target, Error).

Pinout & Connections

Target SWD Interface (J3)

Extension / Debug Header (J2)

Provides access to 5V, GND, and the ESP32 UART (TX-PROG, RX-PROG) for external communication or secondary programming.

Gallery

3D Render

PCB Layout

Schematic

Getting Started

1. Connect OverWire to your PC via a USB Type-C cable.
2. Flash the ESP32 with your preferred wireless SWD firmware (such as a Wi-Fi BlackMagic Probe port or custom TCP-to-SWD bridge).
3. Connect the J3 SWD header to your STM32 target.
4. Connect to the ESP32 over Wi-Fi and start flashing your STM32 remotely!

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License

This hardware design is released under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license. You are free to view, use, and modify this design for personal, non-commercial purposes only. You may not use this material for commercial purposes (such as manufacturing and selling the boards) without explicit written permission from the original author.

Designed with KiCad.