I built N4N1 to learn the details of the ardupilot sailboat firmware. I have had a few student groups building similar vessels at work, and thought it would be worthwhile to go through the exercise myself. Plus I had a boat gathering dust that needed a job. N4N1 uses the ardupilot sailboat firmware on a … Continue reading N4N1 the Autonomous Sailboat
revisited after 20 years! by Michael E. Holden This is a project I did in 2002 to make an autonomous car with a single GPS sensor. No compass or IMU, and it turned out that the GPS of the day only sent updates of position, speed, and heading every 2 seconds or so. The solution … Continue reading Low-Cost Autonomous Vehicles Using Just GPS
Sometimes students or other nice people ask about my Ph.D. thesis. Probably just being polite. Well, here it is. I earned my Doctor of Philosophy in Aeronautics and Astronautics from Stanford University in 1999 meholdenphdDownload
Pet chickens like to run around and scratch up their yard during the day, but must be safely locked away at night to prevent predators from eating them. Most chicken-keepers accept the twice-daily chore of letting the hens out in the morning, and locking them up at night. This is a project to automate that … Continue reading Super Simple Automatic Chicken Coop Door
Back in 2019 I made a remote controlled lawnmower. It is not a very original design, it follows closely the mower from Make Magazine and many other youtube videos, with some modifications to suit what parts I could get. I got an electric wheelchair and an electric mower second-hand, bought a speed controller and some … Continue reading Lawnie the Remote Controlled Lawnmower
This project documents how to make a windvane to sense the wind direction. It was designed for an autonomous sailboat but could be used in other applications. The structure is mostly 3D printed and uses a gopro mount to attach to the hull. The main sensor is a magnetic encoder that outputs an analog voltage … Continue reading Electronic Windvane
This is mostly just to link the video I made. It shows how to run mission planner (ground control station) and start a simulation of an autonomous sailboat (SITL), and how to run the boat in autonomous modes, including tacking parameters and geofencing. Enjoy! https://youtu.be/kzGciG7cCBc
Using ardupilot with a telemetry radio to send data to your groundstation is the easiest setup and works very well. It is limited by RF range, which is determined by the radio power (more power gives more range but costs more and may require a ham radio license). The range also depends on good line-of-sight … Continue reading Ardupilot with Mobile Data Telemetry
I have an Ultibots D300VS delta printer (sadly no longer in production) that I use a lot. It has a Duet Wifi control board, which has a great web interface that can do everything you need to do. Sometimes, however, I wanted to be able to do a task at the printer, and this required … Continue reading Duet Wifi Display
Here are two images I look up often when using ESP8266 boards. I like the NodeMCU versions, they are cheap and easy to use with USB power or a battery. The pins are not labeled in a friendly way for the arduino compiler, however. The arduino compiler uses the GPIO numbers on the chip, while … Continue reading ESP8266 NodeMCU (Arduino compiler) Pins. Now with WeMos D1 Mini!