Pin 13?

[dlmorgan999]

I'm a relative newbie to the Arduino ecosystem, so forgive me if this is something I should already know.  In playing with the DigiX, I decided to start out with a very basic script of blinking the LED.  That worked fine so then I decided to blink an external LED that I connected to pin 13 via a breadboard.  The onboard LED continued to blink, but the one on the breadboard didn't.

I changed my script to use other pins (like 8, 12, and 14) and rewired, and all worked as expected.  It's only pin 13 that doesn't work.  I looked very carefully at the board and didn't see any apparent solder issues.  Am I missing something?

[digistump]

Pin 13 only has very low current driving capability - see this diagram for what pins are low or high current: http://forum.arduino.cc/index.php?topic=132130.0

Most of the other digital pins in the 0-13 range are high current capable which is why it works.

The LED on pin 13 uses a transistor to allow pin 13 to control the larger current the LED needs - which is why that works.

[defragster]

Nice picture and detail.  I found the current info interesting as it shows source and sink values clearly - I had that question yesterday and I didn't come across easily.

[dlmorgan999]

That answers the question - thanks very much.    The post you linked to is also very helpful!