Using Arduino

Hi, I am the head of electronics in my team.
We wanted to be be able to connect the sensors to something that is not the roboRIO, in order to be able to test sensors outside the robot.
We found that teams use the Arduino, and we would like if someone could answer these:

  1. Is it legal? I could not find somewhere where First states that it is legal.

2.What are the uses we can use the Arduino for?

  1. How to connect the Arduino to the robot control system?

You want the blue box in R61–an Arduino is a coprocessor in this case. In general in FRC, if something is not listed as illegal, it is legal. Note that all robot rules still apply.

2.What are the uses we can use the Arduino for?
On the robot, anything that you don’t want the RoboRIO doing, except for controlling motors/solenoids/servos. So, it could process all the sensor inputs and tell the RoboRIO what the current status of the robot is so the RoboRIO can tell the motors to run. Or it could do vision tracking.

Also, an Arduino isn’t the only legal coprocessor.

Oh, and for your third question: Ethernet and USB are good options.

I note that your planned use is “to test sensors outside the robot”.

This is a great use for the Arduino, and since you’re doing it in the off season, or off the robot, then FRC legality really doesn’t matter that much. The FRC rules apply for robots being used in competition. The laws of physics, of course, still apply. So don’t hook 3.3 volt sensors up to 5v power supplies or anything like that, but you won’t be breaking any FRC rules with your experiments this summer.

The Arduino can talk to almost any sensor that you’re likely to want to use it with. The easiest ones are the ones that return either a simple digital signal (like a switch) or an analog signal (like a potentiometer, or Sharp IR rangefinder.) Slightly more complex sensors will return either a pulsed signal (like an encoder) or have a specific communication protocol (like some gyros, accelerometers, an ultrasonic rangefinder (like the HC-sro4) or a CMU camera).

The nice thing about the Arduino is that you can use it to print a display of your sensor readings direct to your computer screen so you can see how the sensor is responding. Your code will be a little different when you use the sensor with the RoboRio, but the logic will be the same, and you’ll know how the sensor works.

For this use I wouldn’t connect the Arduino to the RoboRio, but rather learn how to use and test the sensors using the Arduino, and then connect the sensors directly to the roboRio for competition use. While it makes sense to use a co-processor to off load some computationally intensive tasks, such as vision processing, from the RoboRio, the RoboRio should have more than enough processing power to handle every sensor that you can connect to it.