Is it ok to use P22,P23,P24,P25 if not microSD card on Activity Board?

mrsoft99

On the Propeller Activity Board, if no card is plugged into the microSD slot, is it ok to use P22 though p25 as GPIO's?

The schematic indicates P22, P24, and P25 have 100K pullups to 3,3V, and P23 has no connection. If these are accounted for, I'm assuming it's ok to use these pins for general input or output?


thanks,
buddy

msrobots

Yes. The sd-card slot without SD card is just a fancy connector.

I think @Tubular even made a set of boards to connect via sd card slot.

Enjoy!

Mike

mrsoft99

Thanks Mike,

Unfortunately, I haven't found a good way to actually get jumper wires onto P22-P25!

I'm trying to get as many GPIO pins as possible with the Activity Board and my setup. Can I use DA0 and DA1 to get to P26 and P27? Can I use DA0 and DA1 as GPIO, or does the d2a circuitry mess that up? For example, could I use a Ping or IR sensor on DA0 and DA1?

Thanks again,
buddy

Mike Green

Look at the schematic. P26 and P27 get filtered and sent through a buffer amplifier to become DA0 and DA1 and the audio outputs. If you need a relatively slowly changing digital output (Hz to KHz) like for LEDs, you could use DA0 and DA1, but you couldn't use them for inputs or for high speed digital outputs.

To get access to P22-P25, I'd get a really cheap or otherwise broken mini-SD card and gently break it apart with a fine screwdriver or knife blade, rip out the nice chips, and solder fine wires to the ends of the printed circuit traces that go into the socket.

David Betz

You could try something like this to get access to the SD pins: https://www.sparkfun.com/products/9419
It would be nice if someone made something like this only without the SD card slot.