Hi,

How can I define a bidirectional GPIO? The cypress IC is the master so in firmware we know when it has to switch from output to input.

I defined it as an output in the initialization function (Thread_Entry). In a callBackDma function, I am changing it as an input to read back the data, then change it as an output. Is this method correct?

Thanks,

Nazila

Hi,

I don't see any issues with this use case as long as you know the timing of the switching needed.

Regards,

Anand

Hi Nazila,

I wanted to understand few more things about your use case. Is it ok for your application to have it configured as bidirectional or as you stated do you specifically need it as input for some time and output for some time?

Regards,

Anand

Hi,

I am not sure if I understand your question. By default those pins are output, then sometimes they have to be change to be input. The controller is the Cypress chip.

Please let me know if this is not clear.

Thanks,

Nazila

There is the chance to define a pin as "Digital Bidirectional" pin which saves you any switching, just wrie and read to and from the pin as desired. Use the APIs and do not write to the pin-registers directly.

Bob

There doesn't seem to exist something like a 'digital bidirectional' GPIO - at least I couldn't find one in the publicly available headers or docs. I was bitten by this deficiency when looking for a solution where direction of communication needs to be turned in the middle of a serial communication stream. Configuration of an open-drain GPIO might be possible, but it's still unclear if API checks in the GPIO setter/getter functions prevent doing so.

Ciao!

Daniela