Whenever I sit down for a while to work on a project I’ll end up getting a little obessive. This has its pros and cons but usually ends up working out in the end, save some efficiency. I posted a while back about my first PCB and promised to do a quick update once the remaining components arrived (which they have), so here it is.
In retrospect, I probably should have spent a little more time checking over the board and connections before uploading my files to OSH Park. Past experience has shown me that very rarely will things work right the first time you do them. This project was no exception. The remaining board components arrived a few days ago and I quickly soldered everything in. I tried uploading a program however ended up with a very general avr error that really offered no insight into what was going wrong. I spent a couple hours browsing through forum posts hoping to find some explanation but came up empty handed. The following day I brought the board into one of our labs so I could actually check and see if data was being sent or received through the ATmega. A couple of scope frames later I was able to see that there was communication between the RX and TX on the chip and the FTDI adapter I was using. I rechecked my schematic and everything else looked correctly connected. It then dawned on me that my RX/TX lines might be inverted (which they were). Some ribbon cable and dremeling later I was able to swap the two lines and upload a blink test.
The following day the motors and reflectance array arrived, which I quickly tested to make sure everything else still worked. I cut off a piece of cardboard from one of the boxes I had laying around and mounted the two motors in along with some hot glue to hold the board just so I could see it drive around. My plan is to laser cut a chassis once I have a little more free time, but in the mean time here are some photos and a video:
