DAVE

I am a software engineer. I started playing with technology a long time ago with a Commodore VIC-20 home computer and later a C-64. Programming in BASIC and 6502 assembler was my world. At the same time I was also making electronic circuits; plugging components like LEDs, transistors, op-amps, and logic gate ICs into a breadboard or soldering them onto stripboard and mounting the boards into plastic cases.

This youthful learning was helped by the BBC Micros we had at school where I learned the concepts of networked computing; logging in with a username and password and seeing all your files whichever machine I had logged in on. Eye-opening stuff for the 1980's !

This turned into a career in technology which led me to the BBC at MediaCityUK, Salford. 

About six months ago I became involved in the micro:bit project. This is a partnership of many organizations coming together to deliver an incredible educational leap; a small cheap connectable programmable device to be given free through schools to every Year 7 child of 2016, backed with copious learning resources for teachers and students.

I was very fortunate to be working on this project and I began to think back to the things that I built and the programs I wrote as a youngster. I was especially keen on using the edge connector of the micro:bit to give the tiny board more senses and more ways to interact with the outside world. I wanted to build a robot body for a micro:bit brain!

It was a very long time since I had built anything like this so I started with a kit purchased from the internet. This had nothing to do with micro:bits, just a couple of motors and a circuit board all bolted to a piece of plywood. I just wanted to have a look at what I was getting into. I learned a lot by building that kit and it all went into shaping my ideas for a micro:bit robot.

I wanted two decks on the chassis not just one, so that the components were not crowded together and fiddly to assemble.

I wanted to use a matched set of motors gearboxes and wheels to make the drivetrain robust and make the robot stand level. 

I wanted the finished robot to be easy to open up to allow for modifications, fixes, battery changes and the like.

I wanted it to be a platform for experimentation able to do many different things, not specialized to one particular task.

I wanted it to look simple and friendly, not intimidatingly technical or complicated. I wanted people to look at it and think "I could build that!"

It also needed a name so it became DAVE, the Digital Autonomous Vehicle for Education. So I had a great name and I had my guiding principles. Now I needed to build it.

I bought an edge connector and breakout board from Kitronik who are a micro:bit partner. I bought a twin motor/gearbox with wheels and ball caster made by the model company Tamiya. I bought electronic components from Maplin. I got some plywood, screws, bolts and threaded pillars that would become a roomy double-decker chassis. 

Building the first DAVE was a story of silly mistakes, lessons learned, problems solved and setbacks overcome. DAVE first ran during the Christmas holidays of 2015 and was revealed to the world on February 12th in this Twitter post.  

I had always intended to make two robots, one as a prototype where I would learn the hard way and a second as a clean build that I could document and share. By the time DAVE was completed and running well, the technology had moved on. Kitronic had released a new micro:bit board which took care of many of the problems I had fought with. MicroPython was now live, making programming the micro:bit easier for teachers and students already using Python in school. The next DAVE would not be a copy of the first. It would be better.

My next post will be the story of DAVE 2....