Pypilot is an open-source autopilot for boats, conceived and designed by Sean D'EPAGNIER.

Sean is a brilliant inventor with extensive skills in computer science, mathematics, electronics, and even ergonomics. He has been sailing extensively for many years on a sailboat without an engine.

Sean has always relied on autosteering. Mechanical vanes have limitations, and as he looked for free software solutions, he found limited options. For these reasons, he created pypilot to provide a high-performance, low-power autopilot that we can all trust and that we can extend and modify to meet our needs. Pypilot is free software (GPLv3), and as such, you can trust it to work as intended and for future use without restrictions. Because freedom of modification is guaranteed, users around the world have continually contributed improvements, however small, for the benefit of all users.

Sean is still very active on the pypilot forum. For fortunate personal reasons, he currently no longer has enough time to build us the controllers, computers, and HATs we were lucky enough to be able to purchase from the pypilot store.

Although I have professional resources for designing and manufacturing electronics, I've always preferred to install on my boat what Sean offered in his store. With each upgrade, I've enjoyed discovering and studying his latest improvements. I started by buying a motor controller from him because it's the most difficult thing to make individually if you want a reliable and robust autopilot.

To continue to grow the number of people using pypilot, despite the closure of the pypilot.org store, we offer robust controllers at fair prices, as well as information to help you get started. We'll listen to your suggestions and continue to improve what we're building. Sean will also be able to distribute the improvements we've made when he reopens his shop.

Sean has always tried to have an energy-efficient autopilot. To achieve this, he used MOSFET transistors rated at least 83A, and even two ou four in parallel for the 15 and 30A versions. This allows for very low voltage drop due to internal resistance and, more importantly, avoids the 0.6 to 0.8V threshold of conventional transistors used in some motor drivers. 

With a current of 2A drawn by an Autohelm electric actuator, the voltage drop of Sean's or Navitop's controllers is less than 0.1V (7A controller), 0.07V (15A controller), or 0.04V (30A controller). 

For comparison, with an L298N controller whose two H-bridges are in parallel, the voltage drop in the controller (VCESat) is 2.55V (typical) to 3.2V (max) with a current of 2A according to the L298N integrated circuit manufacturer's datasheet. The use of conventional transistors, sized to supply 1.5A or 3A, explains this. We then have 5 to 6W of heat loss in the controller as well as the overconsumption imposed by the under-powered motor to move the rudder.

A motor controller made from an IBT_2 with 43A max MOSFET transistors avoids the voltage drop of conventional transistors. But the controllers designed by Sean use 83A MOSFETs and even two or four in parallel depending on the power of the controllers, which guarantees very low electrical losses in the form of heat in the controller.