Input Devices


I have always wanted to do a "Clap-on, Claff-off" device to allow me to turn on and off device though a hand clap.  I found the following circuit which generates a digital signal.  If a loud noise is made, the output is high, otherwise is low.  I wanted to do some of the process in analog circuitry because I wasn't sure if the microprocessor could sample fast enough and buffer the signals.

Room Noise Detector-Circuit diagram

After stuffing the board. I was able to use a scope to validate the result of the circuit.  I had to add a resistor between the power and the microphone as per the DigirKey suggested circuit.  After milling the board twice (due to uneven surface), I had a stuffed board:
Clapper Board

I spent over 5 hours trying to connect to the board and to make fuse.  I was able to make a .hex file but received the -rc error when I tried to make fuse.  I checked the hardware to ensure there's no short, as well as to ensure that the microproessor was properly powered.  I decided to make the microphone board given in class as a backup.  I was able to communicate with it (nice that it didn't need a fuse), but because the IDC shope was out of flat 0.1 connector, I used the right angled one for the 6-pin connector used to get power and communicate with the computer.  This ended up shorting the power and ground.  I discovered this after some more time debugging the hardware.  I de-solder the connector off, but not before ripping out some pads.  After some surgery work and using a spare 4-pin connector I found lying around, I had the following:  

Mic Board  

I used Lindy's wonderful tutorial to progrma the board and was able to create a .hex file and download it onto the controller.  However, because the 6-pin connector is missing one of the pin for serial communication, I couldn't get data on the Python code.  I will have to find a new connector and re-solder it.

In conclusion, this week was many hours in the shop making and debugging hardware, and trying to work with the software.  The positive side is that I got a lot of practice in debugging hardware and am getting familiar with the procedure of programming the ATTINY44.  Hopefully with a new board with the issues fixed, I will be able to have my clapper board.