OUTPUT DEVICES

Goals:
1. Add an output device to a microcontroller board.
2. Program it to do something

At the lab
For this assignment I’m going to design a board for the input and output devices at the same time. Both will be in the same board.

The board that I’m going to design will contain the following main elements:

A couple of “Step response” and one piezo-buzzer. When my finger presses the step responses I would like the piezo-buzzer to switch on.

So the input device would be the “step response” and the output device would be the “piezo-buzzer”

It is probably not the most exciting project for input/output devices but I hope it will demonstrate both functionalities.

First of all is designing the board. This is how it looks once it is designed on eagle. We only have one piezo buzzer in the lab and this doesn’t correspond to any design in the eagle’s library. So I had to draw a new library on eagle to design the piezo buzzer.

It took me a long time cause this functionality on eagle is not that evident.

This is the final result:

Once it is done I only need to mill it on the Modela through Fab Modules and then program it. Unfortunately the day I was in the lab the bit of the Modela broke and I couldn't finish on time because it took me some other time to find a new bit...

This is the final result:

Stuffing and testing
Once I had the final board milled it's time for stuffing components

To be continued:
This assignment will remain incomplete till I can finish milling, then stuffing and finishing with the programming.

Coming back to the lab:
Once I'm in the lab again I start milling the board. The milling went easy and then I just needed to program the step response and the piezo. I am working on Niel's program but I modify it in order to adjust my necessities.

The result is the following:



And this is a video of how it works:



What I learned
I liked making this assignments because it showed me how fast the step response was working. The piezo didn't sound extremelly high but it sounded enough to be recognizable. Pogramming in C was very diffcult for me, even I was using an script from other person. I hope to continue programming in Arduino or similar because I just find it simpler.

You can download all the files related to this week here.