Flex Sensor and a Servo

My next project begins with a flex sensor. A strip of material that when flexed varies the resistance of the sensor. At a straight or 180 deg "flex" it gives a resistance of 9k Ohms, roughly. It can give up to 18k Ohms at about 90 deg or fully flexed. Now to interface the sensor to my AVR's A/D converter and measure that resistance.

Now to add a basic hobby servo to the system, a Futaba S3003 Servo. It has three wires Red, White, and Black meaning Voltage supply, Signal, and Ground, respectively. A while back I had developed some basic C code to control a servo and now is the time to test it.

What I want to do is control the servo via the flex sensor. Basically, the flex of the sensor controls the position of the servo motor. Hmmm, interesting applications with this concept. Here are a couple of pictures from my circuit in the works.

Some Flex:

More Flex:

Breakout Board For My AVR

Now with my ISP device, I need a breakout board for my AVR processor. A breadboard works well from time to time but something more permanent is needed. So looking through my inventory on hand I found a protoboard that would work well.



The first thing I started with was the positioning of the processor and sockets for Port Pins. Then I moved on to adding IC sockets for EEPROM, a Real Time Clock, and a D/A Converter. After that I soldered on two pin terminals for easy interfacing to the chip's onboard A/D Convert Channels. The last things I have added are a LCD contrast pot and a system reset button. Now to wire everything up so the breakout board actually works.