Dynomotion Forum

Is it possible to configure any of the I/0 pins to operate in open drain/collector mode when used as general purpose outputs?

I know that the Step/Dir pins on JP7 can indeed be open collector outputs when used as Step/Dir generators. I have not yet found a way to configure them in open collector mode when used as GP outputs though. Is there some FPGA option call - or some other way - to do this?

I have a couple of reasons for wanting to do this:
1) interfacing with the I/O (enable input, etc...) of particular motor drivers
2) Implementing a software I2C interface to interact with some external sensors that don't come with an SPI option.

Thanks,
Jim

Hi Jim,

To make a GP IO pin "open" configure it as an Input with SetBitDirection(X, 0);

Then to drive the IO pin low Clear the bit and configure it as an Output with ClearBit(x); SetBitDirection(X, 1);

HTH

Hi Tom,

Thanks for the response. I will go down that path... I just didn't want to have to worry about any potential timing problems creating the chance of having both IC's driving the lines at different levels - creating a shorting condition.

Thanks,
Jim