Configuring pad control groups on T30

Technical Support
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1

I use an optical encoder with probably too slow rise/fall times but no bounce, causing multiple interrupts to fire for each transition. To avoid having to use polling, I would really like to get the interrupts working.
T30 can have Schmitt Triggers set on pad groups, not individual pins. How do I configure these pad control groups? Didn’t find anything in your libraries. Do I need to write to the pad registers directly, if so how is this done from user code?

Had the exact same issue on a VF61; switching from CMOS to Schmitt type inputs fixed the problem 100%.

T30
WEC7
CE Libraries 2.4

Thank you.
Ebbe

2

I was not aware there was a “Reg Access Tool”. Issue (presumably) closed.

3

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4

Alex, thanks for the reply. I did try “inmode=schmitt”, but Gpio_SetConfigString() failed on that particular value. Should it work? An individual pin cannot be configured as Schmitt Trigger input.

BSP 2.2
Libraries v2.4

Thanks.

  • Ebbe
5

You are right. The “Schmitt” mode does not supported by Toradex Lib for Tegra modules. You can set it using direct access to the pad registers. You can use Toradex CE Libraries: MapMem.h

Map_OALPAtoVA()
and
Map_MemoryWrite()

6

I used the command line Reg Acces Tool and ShellExecuteEx to set the pad registers, but had to resort to some trickery to hide the output.
This approach with MapMem sounds like a much cleaner and better one.

Thank you.
Ebbe