Open Core: The Robot ‘Brain’

Status: Fabricated – Being Tested

A fully open-hardware robot compute unit built around a stackable 10 cm × 10 cm module standard with two Avaota A1 Single Board Computers (SBC) connected via a single ethernet cable. Native CAN bus support enables robust field-level communication. Dual GNSS RTK receivers provide centimetre-scale positioning for navigation and task execution.

All schematics, PCB layouts, and firmware are released under open licences. The system is housed in a rugged, waterproof aluminium enclosure with M12 connectors, designed for long-term outdoor deployment.

Board A: Control & Safety

Primary controller responsible for the robot’s physical integrity and movement.

Core Tasks: ROS 2 navigation stack, topological mapping, and EKF localization.
Hardware: Direct serial link to the ESP32 (Lizard firmware) for deterministic real-time control.
Priority: Executes real-time path planning and emergency stop logic.

Board B: Perception & AI

Dedicated vision processor for compute-heavy tasks.

Core Tasks: Camera drivers, image pre-processing, and neural network inference (e.g., YOLO).
Output: Processes raw video into lightweight detection coordinates or semantic labels.
Priority: High-bandwidth data handling without impacting SBC A’s CPU stability.

Brain Bill of Materials

Component & Link	Description	Qty
Yuzuki Avaota-A1 SBC	Octa-core 64-bit ARM Cortex-A55, 4 GB RAM, integrated AI accelerator.	2
ESP32-S3 Microcontroller	Carrier board for ESP32 for Real-time Lizard control node and general-purpose peripheral I/O.	1
BNO085 IMU	Adafruit 9-DOF Absolute Orientation IMU Fusion Breakout.	1
CAN Bus Breakout	CAN interface breakout for deterministic, vehicle-grade communication.	1
SparkFun GNSS RTK (or Septentrio Mosaic)	High-precision GNSS positioning with RTK support.	2
Tri band GNSS antenna	Antennas for RTK.	2
36V → 12V & 5V Power Isolation	Custom-fabricated power regulation board (~£30).	1
Simple mount plate	10cm x 10cm mount plate with 20mm holes (~£10/5).	1
Waterproof Enclosure	Sealed aluminum enclosure with M22 connectors.	1
22mm Estop/Switch & Wiring	Includes cable, glands/90 elbow, cap, and XT60 inline fuse.	1 set

View full AliExpress Shopping List for Brain Components →

Sowbot: The Body

Status: BOM in review pending move to tracked platform

The Open core module above powers the Open AgBot reference platform. This integrates high-performance motors, precise control, long-lasting batteries suitable for low temp (<0C) charging, and rugged suspension into a fully modular, open-hardware agricultural robot.

Modular chassis and standardised connections enable rapid expansion and reconfiguration, providing full control over electronics, software, and mechanics for a versatile, field-ready system. Note: We are mid-pivot to a tracked platform. (For prototyping, the commercial TR500S may be suitable).

Body Bill of Materials

Component	Description	Qty
Odrive CAN Bus Drivers	High-performance motor control. Open hardware version in dev. Migration to SimpleFOC planned.	2
Nema 34 Odrive D6374	Odrive motor in Nema34 format.	2
12V 80Ah Sodium-Ion Battery Packs	High-capacity energy modules for long-duration operation.	6
Nema 34 gearbox	Ratio TBC	2
5mm Aluminum Sheet & Spacers	CNC cut chassis parts.	4
68cm Tracks	Tracked locomotion platform (TBC).	2
Chassis Connectors	Aluminium 90° crossover and modular pipe fittings for structural frames.	Many

Sowbot Mini (Dev Platform)

Status: Needs Assembly and Testing

A 1/3 scale development platform for testing and validation.

Dev Platform Components	Description	Qty
Driver, Gearbox & Motors	Same as full-size platform above.	1 set
Tracks	Lynx tracks (or cheaper alternatives).	2
Chassis Structure & Connections	1515 extrusion and corner brackets.	Many

Sowbot Pico (Dev Platform)

Status: Physical platform tested. Requires Lizard firmware work.

Under review/testing in light of move to tracked chassis. Track issue here.

Component	Description	Qty
12V 37RPM DC Motor	High-torque speed reduction gearbox with encoders. (~$12)	2
10kg Chassis	Small form-factor chassis. Undergoing testing.	1
Zio 4-Channel DC Motor Controller	Dual H-bridge controller, I²C Qwiic-compatible. ($14)	1
3S Lipo & Charger	DC ~11.4V, 6000mAh battery + USB Charger. (~$30 total)	1 set
Wiring & Connectors	XT60 to screw terminal, 22 AWG PH 2.0 cables.	1 set

Hardware