pyCRUMBS

pyCRUMBS is a Python library implementing the CRUMBS protocol for I2C communication on Raspberry Pi. It enables structured message exchange between a Raspberry Pi (master/leader) and Arduino or other microcontroller devices (slaves).

Features

• Simple API: Easy-to-use classes for I2C communication
• Structured Messages: 31-byte fixed-format messages with automatic encoding/decoding
• CRC-8 Integrity: Matches the embedded firmware's AceCRC configuration for parity checks
• Cross-Platform: Compatible with any I2C-enabled Linux system
• Well Documented: Complete API documentation and examples

Quick Start

from pyCRUMBS import CRUMBS, CRUMBSMessage

crumbs = CRUMBS()
crumbs.begin()
message = CRUMBSMessage(
    typeID=1,
    commandType=1,
    data=[1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0],
)
crumbs.send_message(message, 0x08)

Installation

git clone https://github.com/FEASTorg/pyCRUMBS.git
cd pyCRUMBS
chmod +x setup_pycrumbs.sh
./setup_pycrumbs.sh

The CRUMBS protocol uses a CRC-8 checksum that matches the embedded AceCRC implementation.
Generate and compile the shared library (once per platform) with:

python scripts/generate_crc8_c99.py
python scripts/compile_crc8_c99.py

Hardware Requirements

• Raspberry Pi or compatible Linux system with I2C enabled
• I2C bus with 4.7kΩ pull-up resistors on SDA/SCL lines
• Unique addresses (0x08-0x77) for each peripheral device

Documentation

Complete documentation is available in the docs directory:

• Getting Started - Installation and basic usage
• API Reference - Complete class documentation
• Protocol Specification - Message format details
• Examples - Code examples and patterns

Examples

The library includes working Python examples:

• Leader Example: Interactive interface for sending commands and requesting data

License

AGPL-3.0 - see LICENSE file for details.