Econo Monome

Introduction

A Monome is basically a simple eight by eight grid of push switches and lights. However, the official Monomes have always had a nod towards eco friendliness by incorporating renewable wood in their construction. Well I wanted to go at least one better and use parts that I already had in my junk box, or surplus obsolete parts I could scrounge, all based on a Arduino. This dictated the electronic and mechanical design, resulting in a unique variant on the Monome theme, which is why I call it the Econo Monome.


Let’s kick off by saying that 40 years of working, and playing, with electronics has given me a junk box that is perhaps deeper than most people’s, your mileage may vary. I also was in a position to scrounge samples and surplus parts from my work, finally I did end up buying one or two things but they were minor.

They had the words “ NOT RoHS “ written on in red biro. Since the introduction of Reduction of Hazard Substances legislation has come in to Europe, manufactures are not allowed to use these in any product they sell. As I am not selling this then I thought it fair game, also better to actually use something than throw it away and buy a replacement. Next up, was the prototype board, this was an odd ball board that I had bought about 20 years ago and never used. It has holes space at the usual 0.1” pitch but ever other row was displaced by 0.05”. It had lane in the draw a long time never quite finding a project, but now was it’s time to shine. In fact it was just a touch too small, but just by two holes but I thought I could get round that. When I bought my last Arduino board I also purchased two pre programmed ATMEGA chips, one for a project and one as a spare. As that project was now completed it was time for it to come off the substitutes bench and be a star. Now in the world of professional electronics surface mounting resistors and capacitors have moved on from the small 0803 size parts to smaller 0602 parts and even smaller. Therefore there were plenty of these parts of no use any more, and in an odd juxtaposition large DIL ICs I had bought over ten years ago were sitting in their tubes. I had an MM232R USB to serial bridge hanging about for 3 years from an investigation that went in an other direction. That just left the case, and using the aluminium U section technique I have used in the last project and combining that with spare unused PCBs gave a high tech but recycled appearance.

Well what did I have to buy? Well the green paint for the sides, the styrene I beams for the button dividers and the styrene sheet for the cover. Finally there was a bit of foam to make it all fit.

Finished unit

The Cast List

A Monome from the junk box

By Mike Cook

The Play

Schematic

Construction

The case

Software

Showing the buttons