I'm pretty new to electronics and ive basically been trying to connect around 5 RGB LEDs together so they produce the same colour but arn't simply daisy chained as the voltage gets drained and they just get dim.
Is there anyway to wire them together to be able to control 5 RGB LED's through just 3 analog pins on the arduino to produce the same colour?
Here's the data:
Colour Forward Voltage(V) Current Typical (mA) MCD
Red 1.9-3.5 20 1500-2300
Green 2.9-3.5 20 2000-2700
Blue 2.9-3.5 20 1500-2200
if you wire them in series then yes the voltage drops. If you wire them in parallel then its the current that drops. Which is fine cause if you chain a few together you don't have to use a resistor for each color.
Put all the red leads to one pin, blue leads to another and green leads to the 3rd. Course the common lead on them will be tied together. With 5 of them you won't need a resistor on them.
Its when you chain LEDs together from anode to cathode that that the voltage starts to drop.
You don't say if the LEDs are common cathode, common anode or simply three packaged LEDs with no commons.
What the type is will affect how you can wire them up.
All the cathodes to the red side tie together on one pin.
All the cathodes to the blue side tie together on another pin.
All the cathodes to the green side tie together on another pin.
There might be a chance that they will draw more current then the arduino can support. I'm sure my math is foo but if each needs 20mA on 3V then all they need is 12mA on 5V. But at 5V i'm sure 10mA will be sufficient. So you can have 4 LEDs on a single pin without surpassing the 40mA limit on the pins. With all 5, and without exceeding the limit, they would only get 8mA.
Common anode to +5v.
From each red cathode put a resistor and wire up all the other ends of these resistors to an arduino output.
Do the same for the green and blue cathodes. Each cathode must have its own resistor each coulur must have a diffrent arduino output. The total current of all LEDs going to one arduino output must not exceed 40mA. If the do then replace the arduino output with the collector of a transistor, with the emitter to ground and the base through a 1K resistor to the arduino output.
