Custom circuit uses?

[Zaque]

I have heard of several teams using custom circuits. (I can't think of any right now.) What uses have you used them for, or what ideas have you had for usage?

Thanks,
Zach

[yash101]

A coprocessor to do better image processing. Take for account, the RPi!

They can be much more useful than you may think.

I'm guessing that you are a rookie (because for 3 days it is 2013), so you may/may not have seen robots with lighting. Hook up a Propeller QuickStart or an Arduino and you have a state-of-the-art lighting controller without getting complicated with the cRIO.

[OWilliamson]

Last year our team created a custom circuit using a Hall Efect sensor. We attached 2 magnets (opposite poles facing down) to our front shooter wheel, and then fastened the circuit just beneath the wheel. We attached a PWM cable to the circuit, and we were able to interface it into the sidecar through a Digital I/O pin.

It worked by switching back and forth from high to low every time the wheel would spin a magnet over the sensor. In our code we treated it just like a counter, and from that data we were able to get the rotational speed of our shooter wheels.

In hindsight it probably wasn't the most accurate sensor that could have been used in that application. But, for our purposes it worked extremely well and were able to keep most of our shots in a very tight group by using it.

[Gray Adams]

Originally Posted by OWilliamson

It worked by switching back and forth from high to low every time the wheel would spin a magnet over the sensor. In our code we treated it just like a counter, and from that data we were able to get the rotational speed of our shooter wheels.

That's pretty much an encoder, so that's a pretty good solution if you couldn't use a standard encoder or just wanted to get deeper into the details of how an encoder works.

Hall effect sensors or reed switches can be great though, a little creativity can make them a lot more useful than a limit switch.

[yash101]

Though this would be very unlikely to be needed, you can have an MCU processing sensors for you to save I/O on the cRIO. The Propeller could be a good choice because it will support up to 32 sensors.