I haven’t been able to find in the rules…am I allowed to use, for example, a 7.2V battery to operate LEDs on a custom OI box?
I believe the answer is no. I don’t have the rule handy at the moment, but you are limited in your power sources at the driver station. A laptop computer can use a battery, and the USB chicklet (should you choose to buy and use one) has a specific rule allowing it – and only it – to use an external power source… but anything else connected to the OI has to be powered by the OI.
And there isn’t a lot of juice there. Some… but not much.
Jason
Here you go. It is found in the Robot Rules Manual. (BTW, knowing the rules relating to the game and robot is VERY valuble, hint, hint.)
From the FRC Rules Manual.
“<R83> All equipment connected to the joystick ports of the Operator Interface must be powered
solely through the power available through the port. External power sources of any type are
not permitted on any equipment connected to the joystick ports. Portable computing
devices can not be connected to joystick input ports on the Operator Interface. Powerpassive
devices (e.g. joysticks that draw their power solely through the Operator Interface
joystick port) are permitted. The one exception to this rule is Innovation First Incorporated
USB adapters (IFI Part Number USB-CHICKLET) may be used to connect USB devices to
the joystick ports of the Operator Interface. If used, this USB adapter must be powered with
a 7.2V battery similar to the back-up battery. Teams can not use power from the
competition port or any other source to power the USB adapter. The USB adapter must be
positioned within the OPERATOR CONSOLE so that the indicator lights may be seen during
inspection and operation in a match.”
<R83> All equipment connected to the joystick ports of the Operator Interface must be powered solely through the power available through the port. External power sources of any type are not permitted on any equipment connected to the joystick ports…
If your powered LEDs don’t connect to the joystick ports, you’ll be okay.
Note that two of the joystick ports already provide LED outputs that you can control with robot software. See the OI documentation for details.
It sounds like you mean that the LEDs are for the custom box - but again you can’t wire power to anything that connects to the OI!! But if you want the LED’s for aesthetics or to look cool - go for it. We’re thinking of hooking up some neons in our box.
You are allowed to power devices from the joystick ports. You may use the led outputs and the 5vaux pin. The issues is that even with those pins available for power, they will provide a minimum amount of current.
I believe you could if the leds were plugged in to the dashboard port, through a microcontroller like an ATmega or pic.
Anything that does not interface with the joystick ports should be fine. Our team has plans on using a lot of LEDs, which will probably be powered off of a 12V battery (for convenience), and controlled by a custom controller connected to a laptop (which is also our dashboard and is connected to the dashboard port on the OI). The control box, though, is powered solely from the joystick ports.
Do realize that you can feed data out of the control box into the robot through the joystick ports, have the robot copy it back to the User bytes, and read it back out from the dashboard port. It has some lag and uses user bytes, but if you really need the information you can always do that.
(has anyone noticed that Adobe Reader puts a proverbial boatload of carriage returns in any multi-line rule you try to copy out of it? AAGH!)
If I was to take that rule entirely literally, having a power source on any device connected to the OI is illegal, regardless of whether or not the power ever touches the same circuit. However, I think that the judges would be OK with it; just make sure it is easily opened and cleanly wired so that it is obvious the power doesn’t hit any control circuit.
Just my 2 cents.
JBot
Before you make any committment to the construction of your operator console that might include a non-OI power source (other than a laptop computer or the USB Chicklet, which are explicitly permitted), you might want to post the question to the FIRST Q&A Forum. Thinking that the inspectors “might be OK” with an external power source is taking a bit of a chance. I would suggest you get an official ruling from FIRST, print it out, and take it with you to the competitions. Then if the inspectors do have an issue with your design, you have an official ruling to fall back on. None of the answers here are official, and they won’t help you with the inspectors.
-dave
Does the Chicklet provide power to devices connected to it?
Could it be used as a legal battery power supply rather than as an Xbox controller?
What would be available?
<probably better posted on the Chicket thread>
The Chicklet is strictly used for a controller that is integrated to your robot. Using a power supply to power the chicklet and then plugging the item into the chicklet is just asking for a way around the rule. Its like “Can I get in trouble for a bank robbery as long as i have someone else do it for me?”
I’m thinking more along the lines of custom controls that communicate to the Chicklet as if it were an Xbox or other controller and draw power to operate from it. A lot more unique possibilities than buying off-the-shelf controllers.
I think i would be easier to just make it into a serial port than to make it into a USB port.