I am with a pre-rookie team from Washington Illinois and our first robot is a T-shirt launcher bot. We have the standard electrical board with 4 talon controllers going to 4 motors. All is controlled by an Arduino with Robot Shield, hooked up to a digital sidecar. Our problem is that we need a way to hook up a solenoid to our power distributor but also have a button wired into the PWM ports of the sidecar to distribute 12V of power to solenoid valve when pressed. I have no idea what to do but I do know how to solder, any help is awesome!
Though I’m pretty sure there are many ways to program this, on ours, we have a simpler solution.
On our t-shirt robot, we just use a model airplane-type servo that hits arm-type limit switches. We just have a two-barrel shooter, so all the way left, shoot left shirt–all the way right–shoot right shirt.
If you have more solenoids, you could progressively hit more limit switches the farther you move the servo.
And welcome to FIRST. you’ll have a great time.
Can you provide a quick sketch of your pneumatics system with the part numbers of solenoids?
The simplest solution is to use digital pins on the Arduino to trigger a relay or MOSFET that switches 12V (or 24V) to your pneumatics solenoid “on” or “off”. Depending on your setup, you may need two circuits. Here is a video that demonstrates this.
Relay board from ebay.
Video of our breakaway bot running on ardunio and robotopen
Edit: Just realized that the video was just driving, not kicking. Here is a picture of the completed control board with the relay board driving the solenoids.
The t shirt launcher uses compressed air from a 5 gallon air tanks which is fed to a reserve tank that goes to a modified sprinkler valve with a 1/4 in 12Vdc solenoid valve link- http://www.amazon.com/Electric-Solenoid-Replacement-Pipelines-Applications/dp/B00827FP26
Here’s the basic idea: Use a general-purpose digital output from the Arduino, which is 0 or 5 volts. Connect it to a relay (Radio Shack sells these; for example This One, but you should be able to find something locally. It’s OK that it’s 3 Volts, it’s not that critical.)
The arduino controls the relay. The relay switches whatever voltage you want to the solenoid valve. Done.