A second-generation build on the open-source robot. Hardware, firmware, vision — all documented in the open.
A small bipedal robot. Open hardware. Open firmware. Open everything.
| Component | Spec |
|---|---|
| Height (standing) | ~24 cm |
| Weight | ~1.2 kg (with battery) |
| Degrees of freedom | 8 (2 per leg × 4 joints) |
| Servos | 8x high-torque digital servos (metal gear) |
| Main controller | STM32F4 @ 168 MHz |
| IMU | 9-axis (gyro + accel + mag) |
| Foot sensors | 4x force-sensitive resistors |
| Battery | 2S 7.4V 850mAh LiPo (~30 min runtime) |
| Camera (optional) | Pi Camera v3 or USB webcam |
| Wireless | ESP32 co-processor (WiFi + BLE) |
Every part. Real cost. Real suppliers.
| Component | Spec | Source | Unit price |
|---|---|---|---|
| 3D-printed chassis (PLA) | v2, 12 pieces | Skytech factory | ~¥80 |
| Carbon fiber legs | 3K twill, 2mm | Dongguan supplier | ¥45 |
| Servos (×8) | 20kg·cm metal gear | Feetech / Waveshare | ¥45 ea. |
| STM32F4 board | Black Pill F411 | WeAct Studio | ¥35 |
| Custom servo driver PCB | v1.2, 8ch PWM | JLCPCB | ¥18 (5pcs) |
| IMU (×1) | BNO085 9-axis | Adafruit | $40 |
| FSR sensors (×4) | Interlink 406 | Sourcing | $7 ea. |
| LiPo battery | 2S 850mAh 30C | CN supplier | ¥55 |
| ESP32 co-processor | ESP32-DevKitC | Espressif | ¥28 |
| M3 bolts + nuts (assorted) | Steel, ~80 pcs | Local hardware | ¥15 |
| Wiring + connectors | JST-XH, silicone wire | AliExpress | ¥25 |
Total per-unit cost: ~¥600 RMB (~US$85). Excluding labor and tooling.
Open development. Real progress.
Side project honesty.
After 13+ years of designing mass-manufactured electronics, I wanted to remember what engineering feels like when the goal is understanding instead of shipping.
OpenDuck is where I prototype ideas that might — someday — show up in our products. Force-sensitive feet. Walking gait. ROS integration. If something works here, it might make it into a Skytech product. If it doesn't, no problem. Nothing to lose.
The robot is named after the open-source OpenDuck project we forked from. Everything we've added — the IMU balance loop, the FSRs, the ROS 2 bridge — is on the GitHub repo. Use it. Fork it. Build your own.
This is the side project that keeps the engineering honest.
Full BOM, schematics, firmware, and build guide — all open source.