Sorry, I think I read too fast and skipped the link.

I’ll let you know how it goes, I might start a thread on the Arduino forum.

The package, symbol, and device that I used to make my Arduino shield is included in the Eagle library posted above. The package is very basic: it includes the locations of the 0.1 inch male headers, but no board outline or anything like that. Here is that link again for convenience. Good luck on your project. Let me know how it goes and if you have any more questions.

would you mind posting your custom “Arduino package” ?

I’ll be trying to make a single sided usb arduino clone and this would really help me out.

Thanks

Ignoring the limitations of the printed circuit board, the shield should be able to drive about 25 light bars. This assumes a forward current gain of 25 and a maximum base current of 30 milliamps, each transistor would be able to sink 0.75 amps or 2.25 amps total.

However, each of the TIP31 transistors are rated for a maximum collector current of 3 amps. In this case, the shield would be able to sink 9 amps or drive 100 light bars! Note that this would require additional transistors to supply the necessary base current to each of the TIP31 transistors because the Arduino cannot supply more than 30 milliamps. Alternatively, you could replace the TIP31 transistors with Darlington transistors.

I say all of this with some uneasiness because I think the light bars actually absorb more than 90 milliamps. Also, I haven’t tested any of this.

how many light bars does this shield support?