Sometimes great ideas come to you at 3:00am in the morning. Sometimes you have ideas that turn out to be….. not so great.
After spending most of yesterday refining my air quality sensor I went to bed with no real plan of what to build for the Nasa Space Apps Challenge. Then, at 3:00am I woke up with an idea.
One of the “Can you build a….” challenges was to build a device to “Make sense of Mars”. The device could contain one or more senors and be used by those exploring the planet. So, all I have to do is take my Air Quality Sensor, add a wrist strap and presto, I have a Martian wrist watch. The idea is to make the kind of thing that a Martian might want to have on his or her person to track local environmental conditions and check for deadly dust storms.
Actually, at this point I must inform the reader that I’ve no idea whether or not dust storms would be a hazard to a martian, or whether or not any of the sensors I’m using (temperature, pressure, humidity and 10 and 25 micron dust particles) would generate any useful readings on Mars. But I’ve seen “The Martian” movie, and I reckon the hero would have found something useful to do with my device. He was a very resourceful chap.
Anyhoo, I reasoned that since there were things on the Martian surface that might be bad and I needed to make sure the wearer of the watch should be in no doubt when these happened. So I added a ring of pixels to my watch to give a strong and powerful warning. And it was at this point that my problems really started. Finding power for the pixel ring was easy, but I also needed a digital signal to select pixel colour.
This was tricky, since the Heltec device I’m using has pretty much all of the signals committed already. However eventually I managed to get the pixel ring to work without breaking any of the existing functionality. Or so I hoped.
The process involved three hours of tweaking drivers and moving devices around pins. During all this I was reminded of the old home truth: “Theory is when you know everything, but nothing works. Practice is when it works, but you really don’t know why.”