Solved: Behaviour of GP182

idata · ‎08-05-2016

I have got another question for my custom board:

It seems like GP182 is at default low state, what is the reason for that?

How can we change it?

The problem is, that on the custom design is a reset line, that always resets if edison is running...

If I unplug the edison everything is working, the reset pin is pulled high by a 10 k resistor.

If I replug the edison GP182 is low and the circuit is not working because reset is permanently low...

I don't want to use a reboot skript just to put GP182 in high state...

The image is based on yocto 3.0, mraa is at version 1.1.1

How can the image be customized that GP182 is not default low?

Is this a bug? All other PWM-Pins are not default low ...

Flo1991

idata · ‎09-01-2016

Hi Flo,

Thank you very much for your patience.

This behavior reported is not considered a bug. Apparently, this is the way the system was designed, so you'll have to initialize and configure the pins to your project needs. It is possible to build and add a recipe to the image that executes a script after boot up, or in fact create a system service that initializes the pins to the desired state during boot time (I believe this is what you're doing right now).

Regards,

-Pablo

View solution in original post

idata · ‎08-08-2016

Hi Flo1991,

Changing the GPIO pin configuration from the images sources would be the ideal option, however, there are no examples on how to accomplish this so it would be a trial and error process that might take several hours. Right now, using a service to set the pin as high on boot would be the quickest way to get it working.

Regards,

-Pablo

idata · ‎08-09-2016

Yes you are right it is the easiest way, but what is the reason for this behaviour? Why is this only on GP182 and not on other GPIOs (I tried all PWM Gpios)?

Normally the default state of a pin should be High-Z ....

Flo1991

idata · ‎08-10-2016

Hi Flo1991,

Let me investigate this a little bit more. Once I have an answer I'll come back to you. Thank you for your patience.

Regards,

-Pablo

idata · ‎09-01-2016

Hi Flo,

Thank you very much for your patience.

This behavior reported is not considered a bug. Apparently, this is the way the system was designed, so you'll have to initialize and configure the pins to your project needs. It is possible to build and add a recipe to the image that executes a script after boot up, or in fact create a system service that initializes the pins to the desired state during boot time (I believe this is what you're doing right now).

Regards,

-Pablo

idata · ‎09-11-2016

Thanks for your answer.

As you already said, I manually set the pin configuration (what solves the problem, but is not nice).

Flo1991

idata · ‎09-12-2016

Hi Flo,

We understand this is not the most effective solution, but this workaround is currently the only solution available. However, we will definitely pass your feedback to the development team to see if something can be changed in the future.

Regards,

-Pablo