This report documents the transition of n3m0 the autonomous boat, originally a monohull designed for long-ish range water-quality measuring missions, to n3m02 the autonomous catamaran. The mission was to add a depth sensor to the boat so that it could survey the harbor at Cal Maritime. The harbor silts in pretty quickly and it is … Continue reading n3m02 the Autonomous Boat: Depth Surveys
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
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
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!
Monitoring the morning brew with the internet of things. Do you want to know when your coffee is done brewing but are too lazy to walk over to see for yourself? Do you need to monitor your coffee pot when you are out of town? Probably not, but here is one solution to the non-problem. … Continue reading Internet of Coffee!
I had an email request to find this project from 2010... I updated the code too! This project takes the pulse from a paddlewheel boat speed sensor and makes an NMEA output on the serial port. It should work with most through-hull speed transducers, and also with windspeed transducers too. The NMEA stream comes from the … Continue reading NMEA 0183 Speedometer
If you're looking for my old site, sorry it got hacked and had to be put down. You can email me (mholden at csum dot edu) if you are trying to find something specific.