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.
- 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
ENandBOOTbuttons for the ESP32, plus two programmable user buttons (TOP1,PROGRAM1) mapped toIO15andIO16for custom firmware triggers. - Status LEDs: Two user-controllable LEDs mapped to
IO12andIO13for quick visual feedback (e.g., Wi-Fi connected, Flashing target, Error).
| Pin | Name | Description |
|---|---|---|
| 1 | +3V3 | 3.3V Power Output to target (from AMS1117) |
| 2 | SWCLK | Serial Wire Clock (Connects to ESP32) |
| 3 | SWDIO | Serial Wire Debug Data I/O (Connects to ESP32) |
| 4 | GND | Common Ground |
Provides access to 5V, GND, and the ESP32 UART (TX-PROG, RX-PROG) for external communication or secondary programming.
- Connect OverWire to your PC via a USB Type-C cable.
- Flash the ESP32 with your preferred wireless SWD firmware (such as a Wi-Fi BlackMagic Probe port or custom TCP-to-SWD bridge).
- Connect the
J3SWD header to your STM32 target. - Connect to the ESP32 over Wi-Fi and start flashing your STM32 remotely!
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.