Off-Grid Farm Automation with Raspberry Pi

A fully custom, self-hosted system built for real-world farm conditions — sensors, valves, and control logic from the ground up.

Our naturally grown, no-till farm

Welcome to the PioT Project — a series chronicling how I designed and built a fully custom, self-hosted automation system to run the real-world farm infrastructure at Stella Porta™. It’s powered by Raspberry Pi, written entirely in C and C++, and built from the ground up with zero reliance on cloud services or third-party automation platforms.

From controlling irrigation valves to logging environmental data, every piece is handcrafted: the hardware, the control logic, the REST API, and expandable device plugins. This system is built for dirt, weather, power failures, and the kind of rugged autonomy you can't buy in a box.

If you're new to the series, start here. This post lays the groundwork — what the system is, why it’s custom-built, and how it’s designed to run reliably without cloud services or outside dependencies. The rest of the series dives into the hardware and software in detail.

• Farm automation made easy as Pi
  01-May-25 — Setting up the foundation for real-world IoT on the farm.

The Hardware

Off-the-shelf just didn’t cut it — much of this system required custom-built solutions, from I²C and 1-Wire interface cards to ruggedized sensor networks and valve drivers that can survive real-world abuse. This section is a deep dive into the tech: how each piece works, why it was built that way, and what it takes to design hardware that holds up to dirt, lightning, and daily farm life.

• Controlling the Irrigation Valves
  01-May-25 — The basics of switching solenoids, safely and reliably.

• Reading from the 1-Wire Sensors
  06-May-25 — Building the temperature sensing layer.

• Using the I2C Protocol to Communicate to Sensors
  07-May-25 — How we wired it, read it, and filtered out the crap.

• Reading Environmental Data with I2C
  09-May-25 — Expanding the sensor net and interpreting the data.

• Raindrops Keep Falling On My Head
  26-May-25 — Detecting precipitation (and making decisions from it).

• More I/O
  30-May-25 — Handling expansion and GPIO overload.

• Rolling My Own I²C and 1-Wire Interface Card
  21-Jun-25 — A custom hardware solution for real-world reliability.

• PWM: A Better Way to Control Sprinkler Valves
  21-Jul-25 — Fine-tuned voltage control for water flow.

• Kicking Zeus's ass
  18-Aug-25 — Dealing with the fun of rural power spikes and lightning strikes.

The Software

I didn’t build the software stack from scratch just for fun — I did it because the system needed to be reliable, modular, and completely independent of third-party cloud services. Written entirely in C/C++, it’s designed to run unattended in real-world conditions, fully under local control. This section walks through the architecture, the REST API, and the logic that makes it all work.

• Getting the Data and Controlling the Devices from the REST API
  01-Jun-25 — Talking to your Pi from across the network.

• Writing Your Own Device Plug-ins
  03-Jun-25 — Custom code to extend your system’s reach.

• Using Software Devices to Build on the Hardware
  06-Jun-25 — Simulated devices and logic layers.

• How to Make Things Happen Automatically
  07-Jun-25 — Trigger-based actions and logic chains.

• Time Has Come Today
  12-Jun-25 — Scheduled tasks and automation routines.

• There Are Always Conditions to Evaluate
  13-Jun-25 — Conditional logic for smarter systems.

• Recording and Accessing Environmental Data Remotely
  01-Jul-25 — Logging and remote access to your system’s mind.

• Preventing Injection Attacks to the Database
  07-Jul-25 — Keeping bad guys out of your Pi.

In the works

• How I packaged the Raspberry Pi for farm use.

• The power supply

• Keeping it secure from hackers.

• Building a web-based user interface.

If you’re interested in some background on the farm itself — the place, the people, and the problems that led me to build all this — I’ve written a few companion pieces that give more context. They aren’t as technical as the PioT articles, but they are part of the story. And like everything else here, they’re grounded in the dirt — not in theory.

• Distance from Disorder
  26-Jun-24 — Why and how we moved to Arkansas.

• Be Water, My Friend
  01-May-24 — Our first irrigation project at Stella Porta.

• The Great Pumpkin Patch Pump
  07-May-24 — Pumpkin Patch Irrigation project.

• Rural Internet
  08-May-24 — Solar-powered Wi-Fi, StarLink, and Cameras.

• The Guest House
  10-May-24 — Southern Hospitality.

• This is My Dirt
  20-May-24 — The Farmsteading Adventure Begins.

Whether you're looking to automate your own homestead, build resilient systems that don’t crumble when the Wi-Fi drops, or just want to see what happens when you give a Raspberry Pi a job and no excuses — this series has something for you. Every post is packed with lessons learned, hard-won reliability, and source code that isn’t afraid of a little dirt. So dig in, fork the repo, and build something that works when the grid doesn’t.

Stay frosty — and stay independent.
— Vinnie