ECE 51 - Group 3 - Multiple QT113s and Conductive Paint

I hooked up two of the QT113 Touch Sensors and used their combined output current to drive a LED. I also tried making some conductive paint instead of the glue. Surprisingly, it worked. The paint was a lot easier to work with too - it didn't clump and I didn't need to rush before it dried as was the case with the glue. Used about a 1:1 ratio of paint:graphite powder.

I hooked each electrode of each QT113 sensor to a strip of the conductive paint (I also painted over the dried conductive paint with normal paint to see if performance was affected - it didn't seem to be). As can be seen, when one electrode is touched, the brightness of the LED is reduced. When both electrodes are touched, the LED turns off. This would allow us to determine the number of sensors that have been triggered.

I'll need to work on a way to determine the location of triggered sensors - the basic idea is simple (a voltage divider), but the resistors will have to be quite small since the output current is quite low as is.

Also, this configuration creates an analog signal, instead of using each sensor as a control for a bit. This will allow us to keep some of the inputs in our Xbee open in case we need them.

Category:

Science & Technology

Tags:

• electronics
• QT113
• Touch Sensor
• Conductive Paint