Bluz DK Schematic Question


#1

I was checking out the schematic today and I noticed something I thought was odd. You have an RGB LED that is using negative logic to be lit, which is no surprise because the MDBT40 can’t source much amperage. What surprised me was the 4.7k resistors you are using with the LED’s. Correct me if I am wrong but your resistor value should be somewhere near 3.3V (VCC) - 3.0V (LED Forward Voltage) / 0.025 (LED Forward Current) = 12 ohms. Why are you using a 4.7k ohm resistor on the RGB LED?