here is a crash course:
http://www.instructables.com/id/Choosing-The-Resistor-To-Use-With-LEDs/
what you are calculating is resitance for a single led, different colors have different voltages and forward currents, so if you want to use the side leds on the on board leds(plateless build im guessing) then you need the same resistors as you would use on the side led.
Thx for the answer henz!
I've calculated resistors before, but my problem/confusion is more based on the seemingly conflicting information given on GONs website.
I guess it would all make sense tho if the supply voltage for side LEDs is different from the backlight ones, and you could actually calculate that the same way but I'm confused by the given information.
The specs for
resistors on GONs website mention:
For NerD Side LEDs of
3V(Green, Blue, Purplish Blue, Pink, White) -
133 Ohm Recommended
For NerD Side LEDs of
2V(Red, Orange, Gold(Yellow)) -
133 or 150 Ohm Recommended
For NerD Switch Backlight LEDs of
2V/3V -
470 Ohm Recommended
So both LED types seem to require the same voltage 2/3V, however the Side LEDs use less ohm which I guess means the supplied Voltage is less for the Side LEDs.
Which would also explain why
not to use the same resistors as for the side LEDs when you use the same SMD LEDs for backlighting as stated in
GONs parts list...
I actually just did the math and the numbers seem to work out very well so I guess this is the reason. So for example:
Side LED: 2V SMD-LED, 150 Ohm resistor, (20mA) -> supplied V seems to be about 5V
Backlight: 2V LED, 470 Ohm resistor, (20mA) -> supplied V seems to be about 12V
So I guess you would actually use the default 470 Ohm for regular and on-pcb backlight, even tho the same smd LEDs use 150 Ohm when used as side LEDs.
Its pretty much just as described on GONs website but different supplied V confused me a lot... xD