I'm new to Arduino and am working on a project with my son. We are using the LillyPad USB board (schematic) to drive a bunch of LEDs (LED Datasheet). Our project is based loosely off of the 'Turn Signal Biking Jacket'.
Our project calls for 7-11 LEDs in parallel on a single circuit. In the 'Turn Signal' project the LEDs are driven off of a pair of output pins (1 HIGH and 1 LOW). In a circuit that looks like this...
Is this ideal? Would it make more sense to connect the LED-chain to Vcc and have the return line connected to a single output set to LOW (to turn on the lights)?
If we were to have 3-4 of these LED-chains on at once, do I have to be concerned with total draw on the microcontroller?