This is designed to be a super small, open source, adaptable control board. Each module is arranged in units of 1.5cm squared, but can handle high power micro robotic actuators, such as my Mighty-Micro-Motors. Ideally, this board can be reused and rebuilt for all sorts of small robots.

You can read up on specific modules in their respective folders in Hardware, or take a look at the overall architecture.

Note that PCBway does not have the proper license dropdowns for this project, so I have selected a similar one. All hardware designs (mechanical or electrical) created by me (the author) are licensed under CERN-OHl-S v2 or later, which is strongly reciprocal and requires attribution and the same license for derivatives, unlike the -P variant that PCBway lists. All code or software pieces found in this repository and written for the hardware is licensed under GPLv3 or later.

Another note is that this is a modular control board, and hence has multiple PCBs available and not just one. PCBway seems to only allow one PCB at a time for the project. I have selected my most advanced module (ESP32-S3 Hub, which is a 6-layer design) for showcasing, but in reality I have designed 7+ sub-boards that you can find them all on my GitHub repository: https://github.com/techy-robot/CACKLE

Architecture

There are currently 6 types of sub-boards:

• Hubs (with an MCU on it, supports 2 or 4 drivers, 2 expansion cards, and a chain of peers)
• PSUs (typically only one board)
• Expansion Cards (vertical mezzanine connector boards for breaking out sensors and other interfaces)
• Drivers (Any high power driver)
• nanoSPI devices (Small 7-pin flex cable SPI devices, mostly for sensors)
• Passives (spacers, end caps, etc...)

The base unit for this project is 1.5 cm squared. The expansion cards and drivers should each be 1 unit, the Hubs 1x1 or 1x2, and the PSUs 3x1 units. With a 12 motor board with PSU for example, the board would be 45x105mm. nanoSPI devices can be much smaller due to the flex cable, such as a 5mm diameter tip and 2.4mm wide cable.

Unfortunately I was unable to create a 45x15mm PSU for the first version, it had to be extended up by 5mm to fit the high current circuitry.

Original (bit outdated) sketch of the architecture:

3D model demo:

Goals

• Adaptable
• Small
• Extendable by other developers
• Easy to use
• Powerful

Features

Required:

• Small modules
• Hubs with a mcu that can talk to its peers and a master
• Motor driver boards that can handle several amps
• Sensor ports with protocols like i2c and SPI
• Extendable architecture
• PSUs
• LED status lights

Nice to Have

• Distributed computing with a multi-master network
• Easy automatic hardware configuration
• Ability to stack hubs vertically using the Expansion Card system, in addition to horizontal chaining.