Senior Design Project Due!!!! Quick Question

I am a senior at UT electrical engineering and we are building a guitar amp for our design project. This amp uses the Beagleboard XM to process the audio signal and send it to the amplifier circuit.

My question…

How many inputs can I have on at the same time?

I am using simulink from matlab to make the audio effects and I read somewhere on there that if too many inputs are driven high at the same time, the board could have an overload in current. I am supplying 1.8V to expansion P9 with a voltage regulator. The way our inputs are set up I could potentially have ~20 GPIO’s on at the same time. Is this a problem? I thought that the BB’s GPIOs would have a really high resistance and that current wouldn’t be a problem but if not please let me know.

My project is due in like a week so please respond quick!



Well. It is stereo input on the analog. So, that would be two. And it is stereo output, that would be two as well.


No I mean physical inputs.


1, 3.5mm Stereo jack.


I’m not talking about the audio inputs. I’m talking GPIO pins. (Digital)

Oh. OK. So they are all 1.8V. I think about 23 if I recall. You can always look at the System rRference Manual and take a look there.


Ok thanks! I will look through the manual and see. Anybody else wanna give an opinion it would be appreciated.

Just read the manual. There are several expansion headers there. I am not sure as to your capability to work with fine pitch connectors. Only one of them has the larger pitch. I don’t know if you plan to use the LCD or not. So if fine pitch is not an issue, then you can use those. The and the camera connector as
well, on the top of the board.


Wesley it depends on how you use these 20 pins. If you want to draw current through these pins then you need to read the processor datasheet and calculate safe values. If you just work with digital signals then you can use all available at the board. IMHO