Bill of Materials
The 3we reference platform is designed to be affordable and sourced from widely available components. The base cost is under $215, reaching ~$300 with optional upgrades for the full research configuration.
Components (Standard SKU - Base)
Section titled “Components (Standard SKU - Base)”| # | Component | Specification | Qty | Approx. Cost (RMB) |
|---|---|---|---|---|
| 1 | Raspberry Pi 5 | 8 GB RAM, with active cooler | 1 | 550 |
| 2 | Hailo-8L M.2 Module | 13 TOPS AI accelerator, M.2 HAT + carrier | 1 | 100 |
| 3 | ESP32-S3 DevKitC-1 | Dual-core, Wi-Fi/BLE, USB-C | 1 | 35 |
| 4 | LD06 LiDAR | 360-degree, 12 m range, 10 Hz | 1 | 100 |
| 5 | BNO055 IMU | 9-axis (accel + gyro + mag), I2C | 1 | 45 |
| 6 | JGA25-370 Motors | DC motors with encoders, set of 4 | 4 | 120 |
| 7 | Mecanum Wheels | 65 mm aluminum wheels with PU rollers | 4 | 160 |
| 8 | USB Camera | 160-degree fisheye, 1080p, USB | 1 | 80 |
| 9 | Safety Relay | With E-stop button | 1 | 30 |
| 10 | Motor Driver | DRV8833 dual H-bridge (x2) | 2 | 20 |
| 11 | Battery | 3S 2200mAh LiPo + BMS | 1 | 120 |
| 12 | Voltage Regulator | 5V/5A buck converter (for Pi5) | 1 | 25 |
| 13 | Chassis Frame | 200x200mm aluminum plate + standoffs | 1 | 80 |
| 14 | Wiring | Connectors, cables, crimps | 1 kit | 50 |
| 15 | Fasteners | M3/M4 bolts, nuts, spacers | 1 kit | 30 |
| Total (Base) |
Optional Upgrades
Section titled “Optional Upgrades”| Component | Purpose | Cost (RMB) |
|---|---|---|
| Intel RealSense D405 (used) | Depth sensing, 3D mapping | 350 |
| Pi 5 (16GB) instead of 8GB | Better VLM inference | +100 |
| Custom charging dock PCB + contacts | Autonomous long-duration experiments | 200 |
| Total with upgrades |
Sourcing Notes
Section titled “Sourcing Notes”- Raspberry Pi 5: Available from authorized resellers (Pimoroni, PiShop, Adafruit). Ensure you get the 8 GB variant for running VLM inference.
- Hailo-8L: Order the M.2 module plus the official Raspberry Pi AI HAT+ carrier. Optional if you only plan to use cloud inference.
- ESP32-S3: Any S3-based devkit with USB-C works. The reference firmware targets the ESP32-S3-DevKitC-1.
- LD06 LiDAR: Also sold as the LD19. Verify UART interface compatibility.
- JGA25-370 Motors: DC motors with built-in quadrature encoders. Used for Standard SKU.
- Mecanum Wheels: 65 mm aluminum wheels with PU rollers for Standard.
- Battery: 3S 2200mAh LiPo with integrated BMS.
Parts Sourcing
Section titled “Parts Sourcing”Taobao (China)
Section titled “Taobao (China)”| Part | Search Term | Typical Store |
|---|---|---|
| Pi 5 | ”树莓派5 8GB” | Official Pi store |
| Hailo-8L | ”Hailo-8L M.2 AI Hat” | Waveshare |
| ESP32-S3 | ”ESP32-S3-DevKitC-1” | Espressif store |
| LD06 LiDAR | ”LD06 激光雷达” | LDRobot store |
| BNO055 | ”BNO055 九轴” | Various |
| JGA25-370 | ”JGA25-370 编码器电机” | Various |
| Mecanum wheels | ”65mm 麦克纳姆轮” | Various |
| DRV8833 | ”DRV8833 电机驱动” | Various |
AliExpress (International)
Section titled “AliExpress (International)”Search the English part names. Most ship worldwide in 2-3 weeks. The LD06 LiDAR and mecanum wheels are particularly easy to find.
No Custom Parts Required
Section titled “No Custom Parts Required”The first-generation platform uses zero custom PCBs. Everything connects with standard dupont wires, USB cables, and screw terminals. The custom charging dock PCB is optional and only needed for autonomous long-duration experiments.
Basic SKU (~$95)
Section titled “Basic SKU (~$95)”A lower-cost entry point for students and hobbyists. Uses the ESP32-S3 alone (no Pi 5, no Hailo), with 48 mm wheels, N20 1:90 motors, and HC-SR04 ultrasonic sensors instead of LiDAR.
See the full BOM details for all SKUs and alternative parts.