Looking for help with the ultimarc trackball LED lights. I am using a raspberry pi 3 for the games
If you're using this Ultimarc RGB LED board,
DO NOT try to use 5v from the RasPi to power the trackball LEDs.
6 RGB LEDs ==> 18 channels @ 20ma each channel ==> 360mA (this greatly exceeds the current rating for the RasPi 5v pin)
any 5V source can keep it powered on all the time.
I see that you have power to the other LEDs on your admin panel and coin door.
If you're powering them with a 12v power supply, you can use a voltage regulator to step the 12v down to 5v.
- Lots of options available on Amazon, search for "12v to 5v regulator"
You may also want to put a variable resistor (or potentiometer) inline with the Red, Green, and Blue channels so you can control the brightness and color balance. Assuming max 120mA and min 60mA per channel:
- Min Resistance 41.6 Ohms = 5v/120mA.
- Max Resistance 83.3 Ohms = 5v/60mA.
- Watts = Volts * Amps ==>
0.6 Watts = 5v * 0.120A- Look for 100 Ohm,
1 Watt variable resistors. (or potentiometers)
Scott
EDIT: On second thought, that Wattage formula isn't correct because the potentiometer isn't dropping all 5v.
It should be Watts = (5v-LED voltage) * 0.120A
Not sure about the voltage drops on your LEDs, but typical LED voltage drops are 1.9v (red), 3.1v (green), 3.1v (blue)
If these values are accurate, you'll only need 1/2W for red and 1/4W for the green and blue channels.