Up to 16 connections can be defined as PC-Controlled LEDs. You can also use these for other output functions.
These LEDs are controlled by a software application on the PC. There are sample APIs for developing your own applications to add LED control.
You can also assign LEDs to behave as keyboard CAPS, NUM and SCROLL lock LEDs. They will be turned off or on in the same way as your regular keyboard LEDs.
Maximum current draw is 30mA per pin.
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.