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[on:]

Hi Folks, first post..

I'm looking for a card that for the Audio Control Panel in my sim - the box has:

13 pots - std 10k rotary
36 digital in - switches
33 digital out (led's)

What card do you recommend for this? In order to reduce wire harnesses, I would like the card to be onboard the box, with just pwr and usb out -

Thanks in advance!

Farrokh.

[Reply #1 on:]

82 IO?
Check the Mega, see if that has enough.
Otherwise, will need to add some multiplexing.

You  have current limit resistors mounted with the LEDs?

[Reply #2 on:]

Hi -

Check the Mega, see if that has enough. -

looks like, 13 pots ok, but may run some short on the digital in/out - can omit a few channels if needed



You  have current limit resistors mounted with the LEDs?

no, but can be added to match outputs - free to use any led type as i haven't started building the box yet.. can work backwards from the card...

thanks!

[Reply #3 on:]

You can use the analog pins as digital also if you haven't done so already.
Another option is to mount an '2560 processor on a standalone board - I posted a link to Schmart boards for one yesterday - and get access to all the IO that is available - might be enough that way; am not sure how many of the 100 pins are tied up for power, ground, xtals, etc.  Looks like 11 pins are VCC/GND/Aref, 2 for Crystal, so 87 available IO lines?

[Reply #4 on:]

Thanks CrossRoads - I don't own a card as yet, was researching the best one for this app.... will read thru the docs some more...

The ATmega2560 is listed max i/o of 86....  so should work -

cheers,

[Reply #5 on:]

I ordered a couple of 2560's from Digikey, and a couple of the Schmartboard 100 pin 0.5mm QFP boards.
Gonna add a 10K resistor, 16 MHz xtal, 22 pf caps, and 100nF caps, some 0.025" square pins for an ISP and Serial programming interface, have a standalone Mega2560!