I N P U T D E V I C E S
STEP RESPONSE
The assignment was to add a sensor to a microcontroller board and read its output.
THE PROCESS:
1-Make the microcontroller board
2-Program it
3-Attach the sensor and read their output
I chose to make Neil's step response board because it seemed the most simple, yet useful design. I thougt it would be a good introduction to input devices, which I confirmed to be true. I realized the sensors are more for actual touch than proximity as they only measure proximity only at a very close range.
The creation and programming of the board went without a problem, especially since David Mellis miraculously helped me get my FABISP working.
Despite that everything went well with programming, once the sensors were connected, the board wasn't working. We determined it was a problem with communications and so David showed me how to run rx.py in order to check the output the board was transmitting. This confirmed a problem in communications, which David helped me resolve by changing the timing specifiec in the c code for the program.
Once this was adjusted (I tried a few numbers to see which one gave me the most responsive output) we ran rx.py again and got a more desirable output, which David explained to me should look like below.
Once the timing issue was fixed, the sensor worked perfectly well and I was able to test the pads to determine which one was ground, which was the sensor and which two were the resistors. The images below show the readings I recorded using Neil'l python script for step response.
Once I tested out the pads one by one, I was able to determine which was the sensor since it was the only repsonse I got. Then I tested all the other pads against that one to determine which one was ground and which other two were the resistor pads.
Lessons Learned
Setting up the necessary programs in order to get the micricontrollers working is possible on a windows machine. It does take some more tweaking around and downloading a few more things, but it can be done.
Whenever a board doesn't work no matter what you have tried, ask David Mellis...