Python Serial Port Programming with PySerial

Serial communication powers the world's industrial infrastructure, yet most Python developers learn it through trial and error. Whether you are reading sensor data from an Arduino, polling a Modbus energy meter on an RS-485 bus, or building a test rig that validates embedded firmware before it ships, the gap between a script that works on your desk and an application that runs reliably in production is enormous. This book closes that gap completely.

Starting from PySerial internals and port management, you will quickly move into designing production-grade communication layers with CRC validation, automatic retransmission, and precise Modbus RTU timing. You will connect Python to Arduino and Raspberry Pi in ways that handle connection loss, device resets, and state resynchronisation without human intervention. You will acquire high-frequency sensor data at thousands of samples per second, implement a complete Modbus RTU master from scratch without relying on pymodbus, reverse-engineer undocumented binary protocols from packet captures, and integrate Python with PLCs, variable frequency drives, and smart meters across RS-232 and RS-485 networks.

The book covers asynchronous serial programming with asyncio alongside the threading model, so you can choose the right concurrency approach for your application. Security in industrial serial networks is treated as a first-class concern, with chapters dedicated to application-layer authentication, anomaly detection, AES-GCM payload encryption, and tamper-evident audit logging that meets regulatory compliance requirements. You will build a production-grade serial protocol analyser with a REST query interface, automate hardware validation with a pytest-integrated test framework that generates compliance-ready reports, and package and deploy serial services as systemd units on Raspberry Pi fleets using Ansible.

Two full-length real-world projects tie everything together: a distributed industrial monitoring system with RS-485 device networks, Raspberry Pi edge hubs, TimescaleDB cloud storage, and a live operator dashboard, and an automated hardware test rig with parallel multi-station execution, instrument integration, and signed compliance reports. The book closes with a forward-looking chapter on the Web Serial API, OPC-UA integration, safety-critical serial requirements under IEC 61508, and keeping a PySerial codebase maintainable as hardware generations change beneath it.

What you will learn

Design a reliable binary framing protocol with CRC-16 validation, sequence numbering, and automatic retransmission that works correctly under real production conditions
Build a complete Modbus RTU master from scratch with precise inter-frame timing, exception handling, bus collision recovery, and a priority poll scheduler for large device networks
Implement multithreaded and asyncio-based serial pipelines that handle high-frequency data acquisition, multiple concurrent ports, and upstream MQTT and HTTP publishing
Connect Python to Arduino and Raspberry Pi with command dispatch, response routing, automatic reconnection, state resynchronisation, and over-the-air firmware update triggering
Reverse-engineer proprietary binary protocols using packet capture analysis and integrate Python with PLCs, VFDs, and smart meters across multi-vendor RS-232 and RS-485 environments and more