Stacy DeRuiter's How To Make Almost Anything Blog - Final Project

December 11, 2005

Progress on my project is slow, but measurable! Right now, I am trying to progress toward a logging ultrasound hydrophone in baby steps. The first step: record audio from a microphone and store it on a flash memory chip, then retrieve the data later via a serial connection to a computer. Learning to talk to Flash memory proved much harder than I thought it would be! So far, I have designed my PCB and written code that can begin recording when a button on the board is pushed (with a little LED flash to let you know it's working). The board takes input from a microphone, converts it to digital using the microcontroller's ADC, and then stores it in memory. Here is a list of the parts I am using for this logging microphone #1: When I get a board working, I will be coating it with our meltable, peel-off protective plastic coating for waterproofing. Here are pictures and code developed so far:
Assembly code to record to Atmel 1M flash memory -- this code is heavily annotated. I hope it might be useful to someone else some day: the only examples I could find of this type of data logging were in c-code, and c-code does not immediately help you know how to write the corresponding asm code.

My plan of action over the next week: Get to as many of the list items below as possible, in the order they are listed.

If you want to see previous iterations/thoughts about this project, please see the Week Four Project Planning page. Here's the latest...

November 28, 2005

After talking to my advisor, I have decided that it would be much more useful to make a logging hydrophone than a logging accelerometer. It needs to be as small as possible, and needs to have: