Hi Tom, It's Peter from National Instruments technical support department here. I remember I had a similar problem with my final year university project.
The best way to do this would be to simulate a stepper voltage and write pulses of different lengths to the LED's. For example, for maximum brightness, just leave the voltage on all the time. For half brightness, have the voltage on for 10 ns and then leave it off for 10 ns. Simply adjust these levels of on and off time depending on how bright you want the LED. As long as you keep the on/off times very short, the LED won't fade before the voltage is applied to it again (at least not enough for the user to see the flicker). You will probably have to do some experiments to find the ideal timings to get the correct balance of brightness and flicker. The 6024e card has a minimum pulse width of 10 ns which is easily short enough to perform this kind of operation. If you need any more help with this then please feel free to contact me again. Best regards, Peter H Applications Engineer National Instruments
