Is it possible using the ARM9 to configure a pin as both input and output? I need to be able to write to it and then read from it. This would be done as an open collector configuration. I have tried changing the DDR and the GPIOOUTPUT registers on the fly, but this did not work.
Thanks, Joe
I haven't done it with ARM but I know it is doable with PIC: output digital 1 to charge up a capacitor, and then switching to analog input on the same pin to adc the voltage decay.
I would imagine it is the same for ARM. your problem might be latency: maybe you wait a little bit longer before you read it back?