project 4: internet of things

Ale Davila

arduino: exercises

ex4.1 LED light
ex4.2 light with switch
ex4.3 digital control

arduino: chessboard project

My initial idea was to create a chessboard which could record each move the players make. My short term goal was to create a proof of concept, an arduino circuit which could detect when a piece was on each square. I decided to use light sensors which would sit in a hole in each square, and would be covered up when a piece was placed there. In this version of the circuit, I also wanted the arduino to emit a unique tone or melody when a piece was placed on a certain square. This would give real-time feedback that the move was detected and would be more fun for me to make than a circuit that just printed text to the computer.

First attempt circuit.
First attempt code.

My first attempt at making the arduino circuit for my chessboard. When I plugged in the board and ran my code, all I got was the piezo playing a single tone.

I went back to study other people's arduino projects. This circuit successfully printed light level readings to the serial monitor.
This circuit from the Arduino website played a tune on the piezo.

Now that I know how to make these circuits and program them, I can start making my own and hopefully have more success.

A circuit which will detect whether light is coming to each of the two sensors.

This circuit allowed me to troubleshoot any issues with the light sensors before getting the piezo involved. I found that each light sensor had a different sensitivity, with one giving values around 200 from the ambient light, while the other gave values around 20. I incorporated this into the code for my final circuit.

My final circuit. I succeeded in making the piezo produce a different tone depending on which light sensor was covered :) but I didn't anticipate that using the loop section would make it beep repeatedly.

Unfortunately my chessboard was not actually sized properly to fit over the arduino board, so I can't demonstrate it that way. If I was to continue this project I would have to work out some way to have the piezo beep only once when the sensor triggered it.