Hi
I was looking at this schema for the RGB leds, but I dont see how they are connected to the ground, because no slot is connected to the - (minus); how does this work? Can anybody explain?
thanks already!
i believe that the leds are connected to ground... if you look closely there is a gray line to ground from common
The longest pin is ground and you have to use it 
In this case its called the common anode.
And i think the scheme is wrong because it sends the common anode to 5v...
The longest pin is ground and you have to use it
In this case its called the common anode.
And i think the scheme is wrong because it sends the common anode to 5v...
So many wrong things.
The longest pin is ground and you have to use it Smiley
In this case its called the common anode.
And i think the scheme is wrong because it sends the common anode to 5v...
yes thats what i also noticed, and there is no connection to the ground, it's all connected to the 5V, so what's the solution?
I have to admit I find that whole thing very difficult to read.
According to the info at the top the LED modules are COMMON ANODE, which means the anode should then be connected to +5V and to correctly turn each LED on you ground the specific cathode via the current limiting resistor to turn an LED on. This has the effect of the LEDs being "active low" and you have to invert your logic that drives the LEDs where sending a "1" will turn the LED off and sending a "0' will turn it on...
I don't know why they used common Anode LED modules for teaching purposes because this is confusing and its better to common cathode, where the cathodes are grounded and each LED is turned on by a 5V signal. Or am I missing something?
If the device is a common anode, then the anode goes to +5V (that's why it is called an anode).
The cathodes go to digital pins (via suitable resistors), and the digital pins are configured as outputs.
Writing a LOW to the digital output lights the LED, as current sinks through the LED and the ouput pin.
Writing a HIGH to the digital output turns off the LED.
If the device is a common cathode, then the cathode goes to GND.
The anodes go to digital pins (via suitable resistors), and the digital pins are configured as outputs.
Writing a LOW to the digital output turns the LED off.
Writing a HIGH to the digital output turns the LED on, and the output pin sources current through the LED.
If the device is a common anode, then the anode goes to +5V (that's why it is called an anode).
The cathodes go to digital pins (via suitable resistors), and the digital pins are configured as outputs.
Writing a LOW to the digital output lights the LED, as current sinks through the LED and the ouput pin.
Writing a HIGH to the digital output turns off the LED.If the device is a common cathode, then the cathode goes to GND.
The anodes go to digital pins (via suitable resistors), and the digital pins are configured as outputs.
Thanks for the reply, I can also use Analog output instead of Digital? Because digital can only write out 7 colors and analog > 7 ?
I will try it tonight
can also use Analog output instead of Digital?
Yes, of course, just remember that with common anode, "analogueWrite(255);" turns the LED off.
If you want to continue thinking of "zero == OFF, 255 == ON", then simply subtract your luminance value from 255.
e.g. Assume you want to set your LED's brightness to 75%:
byte brightness = 75 * 255 / 100;
analogWrite (255 - brightness);