Internal RGB LED - 1kOhm series resistors

im working on a PCB design around the P1 module and noticed 1k resistors in the reference design for the Photon in series to the internal RGB LED ( I’d like to include the same RGB LED in my design with 3.3 VCC. But I cannot get my head around the 1k resistors. Aren’t those too large, especially when looking at the datasheet of the Cree CLMVB-FKA LEDs with forward currents of 10mA(G,B) / 20mA ®? Why was this value chosen?

Thanks in advance,

The larger resistors are to make it less bright.

If you’ve seen the RGB LED on the Spark Core or the SparkFun Photon Red Board (actually a P1), you’ll better appreciate why it was done.


Wow. My engineer and I never checked this. We’d love for it to be far brighter!

presuming 1k would be the solution!