Love-O-Meter from Arduino Projects Book

Using Arduino LEDs and Multiplexing
1

Hello everyone, I have a question related to the arduino starter kit project "Love-o-meter".

why are the 220 ohm resistors attached to the cathodes of the leds when the voltage/current flows through the anode of the leds?

I thought that the resistor goes through the anode to reduce the amount of voltage/current going through the led diode and prevent it from burning up.

Is it different when the led diode is connected directly to 5 volts and not a pin? Can someone explain?

2

It makes no difference which side of the LED the resistors are on. The resistors are still in the LED circuit and so are limiting the current flowing through it.

Steve

3

Note rule no. 1.