I spent most of this week working in Eagle. I began the week by trying to create boards with multiple sensors on them, and that had the same form factor as the Arduino pro mini. This would allow us to put the device into a very small package. The problem is eagle layout is a very slow and tedious process and I was not making very much forward progress but I was learning. After a day of working on the multi chip boards I had a meeting and we decided to table the multi chip boards and to work on making a board with just one sensor on it. The purpose of this is not to create something to be used in the proper deployment but to familiarize me with the whole process of going from an eagle layout to a printed board and then assembling the components onto the board. The sensor we choose to work with for this process was the gyroscope. The commercial version of it came on the largest board of all the sensors and had a lot of features we did not need, such as stepping down from 5v to 3.3v. I was able to get the schematics of the board we had and went about the process of simplifying and miniaturizing the board so that it would be the same size as the accelerometer and be stackable with it. This took me most of the week but by Friday I had a board designed that was ready to be shipped off and printed. I found a company to print the board and ordered all the components to solder onto it so hopefully I will have everything and see if my design worked next week or the week after.
In addition to creating a board for the gyroscope I worked on building a prototype enclosure for the sensor system. While that sounds fancy all it really is a PVC tube with an end cap on one side and screw cap on the other.
While this is fairly simple I did have a few small setbacks in it. I was hoping that I would be able to fit the battery in under the prototype in the enclosure, and while this is technically possible it is not a good idea. The bottom of the newest prototype (prototype 3) is very sharp with the solder joints and putting the battery under it is a tight fit so forcing it in enchanters puncturing and tearing up the batter. I ended up having to just make the enclosure longer so that I could fit the battery in the end. Also I did a pretty sloppy job with the PVC cement when I was assembling this prototype so I might just make another nicer one since PVC is so cheap.
In addition to working on the project this week I went on a tour of the NASA Langley facility for most of Thursday. It was a lot of fun, and I did not release how big that faculty was or how much cool since they were doing there.
Next week should be interesting, on Friday the SD reader on the prototype 3 stopped working in a very strange way. I have not been able to figure out what’s wrong with it so I will document what’s going on next week when I have less information. Just know that Friday was a frustrating and confusing day for me, hopefully Monday will be better.