Pushing the Score-publication
git repositories
Pi reading Pots/skin resistance
Pis have no ADC, therefore the simple way to read a Pot's value is via a step response technique as explained in http://razzpisampler.oreilly.com/ch08.html
TO DO
- get 3rd POT to work
hardware
- Rpi breakout board (cobbler) + cable from GPIO to breakout board cable.
- 1x 220 nF capacitor
- 2x 1Ohn resistor
550 ohm pot (values go between 0-800)OR metal points
notes on RPi GPIO
In model 1 there were only 26 in the following configuration
Model 2 B and 3 B keep the same configuration for the first 26 pins, but expand it to 40 pins, in the following configuration
links:
- https://learn.adafruit.com/introducing-the-raspberry-pi-model-b-plus-plus-differences-vs-model-b/gpio-port
- https://www.raspberrypi.org/documentation/usage/gpio/
- https://www.raspberrypi.org/documentation/usage/gpio-plus-and-raspi2/
Software
libaries
install pip
apt-get install python-pip
Pi python lib RPi.GPIO https://pypi.python.org/pypi/RPi.GPIO
apt-get install python-rpi.gpio
scripts
https://git.pzimediadesign.nl/repos/pushingscore_gpio.git/
Circuit
I am using 500K variable resistor(pot) instead.
touch pressure
In order to use touch pressure: I kept the circuit only replacing the variable resistor with 2 metal pins.
The result is very interesting.
- because the circuit is interrupted while no one is touching, the stream or reading is interrupted
- values can go from:
- Max: 3 (very strong,wet contact) (0 if there is a metal connection )
- Min: 273337
To Do
- implement it 3 times
- needs multi-threading
- OSC communication
- design circuit in small prototyping strip board
- change and test script with more than 1 circuit