first what youll notice my grammer isnt the best :)
ok what youll need: 1 transister/mosfet that can handle the current for the water gun motor, this is the one i used - http://www.sparkfun.com/products/10213
- then a diode, i used this one - http://www.sparkfun.com/products/8589
- then a 10k ohm resistor, then a PIR, i didnt use this one but it should work - http://www.sparkfun.com/products/8630
- then a bread board, i used this one - http://www.sparkfun.com/products/7916
- then some jumpers these are what i used - http://www.sparkfun.com/products/124
- then an arduino, i used a uno - and a water gun, which was for me, a pretty hard thing to find around the house, but i got one from a pesticede battery operated sprayer (it had never been used). and i made the sprayer tip using some tubing, a .22 air gun pellet and a tack ( im pretty creative:). last a battery and battery holder that will work for your sprayer motor. oh and also keep in mind this instructable was done by me, a 14 year old who just got into elctonics in the last few months, plus this is my first instructable :).