Our homework was to measure something: add a sensor to a microcontroller board that I've designed and read it. I used Neil's initial helloreflect board design,
but then adapted it for my needs in Eagle. I plan to use this board as part of my final project, which I THINK will be a racetrack finish line.
Challenges
Electronics continues to challenge me. Every time I think I'm making progress, I have a setback, or two, or three.....
Eagle confuses me.
I do fine dropping components onto the schematic, although in the past I have chosen the wrong ones. Yikes! When I get to labeling the schematic, I run into trouble.
As I study the board design and connections, I have trouble understand what connects to what and whether a path leads directly to a pad or passes it. This is NOT easy for an electronics beginner!
Soldering
I soldered using a home soldering station. As I have said many times, I LIKE soldering and even though there were some new hurdles this time, it came out okay.
I used sticky rosin rather than flux because that's what they had on hand. I didn't have a small brush, so I ended up rolling up a paper towel; however, I got TOO MUCH
rosin all over the board, as you can see in the picture. Still, the board looked fine. It didn't cut out because the double-sided tape slipped as the bit was going to cut the outline.
Programming the Board
SO MUCH EASIER THAN BEFORE!
I used the Fab Academy Tutorial on Makefiles and it was fairly easy to follow with Scott's help.
I can't even explain the joy that I felt when I ran my finger across the phototransistor and the interactive bar graph reacted! We tried shiny objects and got more
of a reaction. It was so fun, and the longer it was plugged in and the board caught the lighting at different angles, the graph reacted MORE. Exciting!
I Learned...
The helloworld board uses an LED as a light source and the phototransistor detects the light. The practical applications for a board like this are many. I visited a FAB Lab recently that had
a person counter on the door that consisted of a reflective pad on the door. The door opened and when a body crossed between the pad on the door and the photosensor on the opposite side, it counted that person.
I am planning
to use the helloreflect board as my inspiration for my final project to detect when a toy car crosses a finish line in a race.
I used Neil's code, which you can find below: Input terminal log helloreflect code in C helloreflect make file
