CIRC01 Sparkfun Inventors Kit

Development Boards Arduino
1

Hello All,

I had taken electronics a few years ago in highschool, and being a programmer professionally, I have sparked some recent interest in playing around with micro controllers.

That being said, I was looking at the CIRC01 on the SIK(http://www.sparkfun.com/products/10173) introduction document.

http://www.sparkfun.com/tutorial/AIK/AR … -REV10.pdf

and a better view of the circuit:

http://ardx.org/src/circ/CIRC01-sheet-SPAR.pdf

There are a few things I don’t quite get after looking at this.

First and foremost, I do not understand why there needs to be a +5 wire, and a ground wire (also it doesn’t specify what pins those wires are supposed to go into, that has me somewhat confused), when there is already a +5 coming from pin 13 to turn the LED on. So I guess I don’t understand why the +5 wire is necessary if you have the pin 13 wire powering the light. I do understand that the ground needs to be there though.

So I guess to summarize what it is I would like to know:

  • Why is the +5 Red wire necessary when it is pin 13 that powers the LED?

  • Where do the +5 Red and Ground Black wires go to? It never said :\

  • Why is the resistor used at all? And why is it after the LED rather than before?

Thanks a bunch everyone!

2

I think the 5V line is a holdover from another experiment. Normaly you would power the two bus bars with ground and 5V from the micro’s power source. In the case of an Arduino the regulated 5 volts and ground come to pins. If you have a screw-shield, they are well marked on the silk screen. If you have a raw board with female sockets, the silk screen should also indicate GND and 5V. Not sure what your kit comes with.

For this demo, you will be getting power to drive the LED from pin 13 and that current will return via the bus bar and then the black wire to the micro. The Red wire just sits there powering the positive bus that you are not using.