Week 11

Input Devices

Input Devices

The eleventh assignment is to add a sensor to a microcontroller board that you have designed and read it.

I chose to add a microphone to a board.

I followed the directions from Week 11 and milled a board and put a microphone sensor on. I am getting better at milling, stuffing and surface soldering boards. See the associated files for making and programming the board by clicking the files repository on the left hand side of the browser on the opening page.

Using AVRdude to flash the board with the microphone code.

Cell phone picture of the python code process on a Dell PC.

Programing the AT Tiny 45 with hello.mic code.

I used the same coding process we used in the past, but used the hello.mic.45.py python code and hello.mic.45.c C code

All went well with the coding process.

I hooked the board of to my Macintosh via the USB port and spoke into the microphone. The screen displayed a graph of the sound intensity and it varied rapidly as my voice fluctuated.

This is a labeled schematic of the microphone board. This is used to identify the components to pull out of the Fab Inventory and tells you how to orient the components and connectors prior to surface soldering. The ATTiny 45 microcontroller datasheet helped me understand what to connect to the processer pins and the specifications of how the processor handles inputs, outputs, cycle speeds, and what the processor does in the circuit.

I wanted to make certain that I could get the programming working on a microcontroller board prior to designing my own. (The above was an existing design that Neil provided.) An example of my own designed fabricated and programmed board can be found in my final project. (Click here to see the board and fabrication files and programming files.)Scroll to the bottom of the page. You can click here to see a video of the car door actuator that is programmed and functioning. (The pull is so rapid that it is hard to detect on video. You can clearly hear the sound...but the sound does not seem to be audible when linked to the website.

The following files can be found in the file repository on the left hand side of the browser on the home page. hello.mic.45.cad.txt,hello.mic.45.traces.png,hello.mic.45.make.txt, hello.mic.45.py, hello.mic.45.c, hello.mic.45.jpg,hello.mic.45.interior.png, hello.mic.45.traces.png, All files are credited to Neil Gershenfeld 4/1/14 (c) Massachusetts Institute of Technology 2014 This work may be reproduced, modified, distributed, performed, and displayed for any purpose. Copyright is retained and must be preserved. The work is provided as is; no warranty is provided, and users accept all liability.