1Print the 3D part from STL file on project page
Pull plunger out of 2 syringes and put aside. Cut the top and bottom off the syringes with a razor blade (see photo). Epoxy a valve into the ejection end of each one and let dry fully.
3Put together 2 photo-interrupters
Solder the PI into the Sparkfun breakout board, solder on a 1K resistor (the board says to use a 220Ohm resistor but we found 1K doesn't impair the function of the PI and consumes less power), and solder on the 3 pin JST connector. Be careful with the orientation of the connector, it's important! Plug the wire into this 3 pin jack.
4Put headers on SD shield and mount on Arduino Uno
5Connect Photointerrupters to Arduino Uno
- The ground pin on each photointerrupter to the GND on the Arduino
- The power pin on each to the 3.3V on the Arduino
- The signal pin on one photointerrupter to pin 7 and the other to pin 8
You can push the wires into the headers on the SD shield or solder them into place for a more permanent connection.
6Flash the code!
7Test that the photo-interrupters are working
TODO: Write up testing methods