Check out this pneumatic target range – using a Pi, Arduino and our 16 channel PWM breakout, with photos from Maker Faire Detroit!
Shared on the Adafruit Forums!
The project was a pneumatic target range using recycled materials and some common hardware from local stores (mostly PVC pipe and fittings.) The gun uses a 12 amp motor from a discarded Bissell vacuum cleaner to generate the air pressure. The ammo is ping pong balls that have some additional weight added to them. We stuffed them with cotton to give them a little more punch and accuracy. (All of the cotton had fallen out by the end of the Faire though so accuracy got worse as the event progressed.) The balls are loaded into the gun via a venturi tube and they are collected into a bucket after they are shot. Another vacuum cleaner motor loads them into a hopper over the gun for re-use.
The targets are side-lit plexi panels with fluorescent marker drawings on them. The target lights are controlled by an Arduino Mega and the Adafruit PWM breakout board. The breakout board supplies a PWM signal to a pair of Darlington Array chips (transistors) to provide the 12v current needed to light them. A large number of the LEDs used in the targets were recycled from bulbs that were inadvertently used in dimmers. (Don’t ask me how I know.) The Arduino lights the target that you need to hit in order to score. The target hits are sensed using piezo sensors and a small envelope detector circuit that adafruit_support_mike provided in these forums.
The Arduino sends signals via GPIO to a Raspberry Pi computer which supplies video and audio feedback. The video is the scoreboard and the audio is a variety of musical scores by Kevin MacLeod who was kind enough to allow use of his music under the Creative Commons license (www.incompetech.com) I have to say that the music adds a lot to the experience.
This last pic gives a little bit of a look at the scoreboard. You have to peak around the tent support in the center. And you can see a little of the targets at the back of the tent.
…the Arduino, Raspberry Pi, custom electronics and the LEDs were all run from solar power during most of the Faire. Sadly we had some cloudy weather on day 1 so had to resort to mains in the afternoon.
Featured Adafruit Products
Adafruit 16-Channel 12-bit PWM/Servo Driver – I2C interface – PCA9685: You want to make a cool robot, maybe a hexapod walker, or maybe just a piece of art with a lot of moving parts. Or maybe you want to drive a lot of LEDs with precise PWM output. Then you realize that your microcontroller has a limited number of PWM outputs! What now? You could give up OR you could just get this handy PWM and Servo driver breakout. When we saw this chip, we quickly realized what an excellent add-on this would be. Using only two pins, control 16 free-running PWM outputs! You can even chain up 62 breakouts to control up to 992 PWM outputs (which we would really like to see since it would be glorious) (read more)