U-HID Controlled LEDs are LEDs which are turned on or off by switches which are connected to other pins on the board.
Assume you have a pushbutton which has an internal LED. It is a momentary button so cannot be used to directly switch the LED since it would only light while the button is pressed.
You have this button configured as a toggle (push on, push off).
You can assign the LED to this button, and it will light when the button is pressed and go dark when it is pushed again, in sync with the buttons action in the application.
Assume you have a toggle switch which grounds one connection when closed. This could not be used on its own to also control a LED.You could link a U-HID controlled LED to this connection and it would light while the switch s closed.
Up to 16 connections can be assigned as U-HID-controlled LEDs. When you assign these LEDs, you link it to any other connection. The other connection must be defined as a switch. This other connection will control the state of the LED.
Its important to realize that the LED state is not actually controlled by the other switch connection pin directly, but by the boards stored internal state of the control connected to that pin. This means the control of the LED is affected by how the switch is defined as well as its actual open/closed state.
The limit of 16 LEDs applies to the board to stay within USB specificatons on current draw (500mA). The U-Config utility will allow you to configure more than this but a LED count on the status line will show red as a warning. You can configure more than 16 if you are using the outputs as low-current drivers, eg for TTL signals.
The U-HID will drive standard LEDs only.
Pins on J1, J2 and J3 have integral resistors so you can directly connect standard LEDs to these. Other pins will need a series 220R resistor, or use 5 volt LEDs with an in-built resistor.
LEDs are connected between the U-HID pin and ground.
The pre-made modular harness can be used to connect LEDs.