Zac Sketches

- Last updated in Jan 2018

I built this site in June of 2013 and I've been updating it along the way to host some tutorials on electronics for robotics teams I mentor and the stuff our family is working on. My day job is running Fathom5, but this is where I get to archive my hobbies online.

Analog DC Motor Position Controller. In spring 2014 I was asked to serve as a mentor to the York School robotics team competing in the First Robotics tournament in San Jose, California. I was so proud of my kids who received the "Rookie All-Star" award. From our lessons learned on DC motor control I build this demo to help the kids think through motor control problems.

Alfred. Over the summer of 2013, I worked on a little robot project named Alfred. I put Alfred down when I moved out to CA. The most interesting component in Alfred is a roll stabilized magnetometor that I built based around a cutom Arduino shield with mostly Sparkfun components and based on this application note. This allowed the robot to drive based on a heading that was indepent of rough terrain and steep inclines/declines or roll.

Poker Odds. This page is dedicated to Hayden's 2012 science fair project where he looked at the theoretical odds of getting a royal flush in five card stud poker and then built a PHP model to test his theoretical result. He won first place at his science and engineering school for it and third in the city overall.

Power Supply. This page is my work on an unfinished project to build a Lithium Polymer (LiPo) battery, Low Coltage Cutoff (LVC) circuit. Radio controlled electric race cars operated by the hobbyist community make extensive use of powerful LiPo battery packs to run their vehicles. The speed controllers for these RC vehicles also include circuitry to prevent damaging the LiPo batteries, which can occur if too much current is pulled out of them. In the maker/hacker community these power sources are less common; however, I wanted to use an RC battery pack to run Alfred and needed to build an LVC circuit to install in the robot to protect my pack. This project got put on hold when I moved to CA for my new job.

HTML/CSS. This is Hayden's working directory for projects as he learns HTML and CSS. In July or August of 2013 he got the Head Start book on HMTL/CSS and is making great progress in his ability to understand those tools.

"Grey" Code. In October of 2013, Greyson heard about Gray Codes named after Frank Gray (Wikipedia article about him here). Since we call him "Grey" he thought it would be cool to understand Gray Codes. This project is an absolute position encoder that allows Greyson to compare why Gray Codes are a more effective way to encode some information than straight binary encoding.

Motor Sink. Quick reference for a circuit I use on the bench a lot and wanted to share.