BBAI - PRU Pin Question

Been going over as many PRU examples I can and there is one core question I have.

In the example from the Cloud9 Example folder

This uses P9_25 as a PRUOUT

However according to the github system reference manual

P9_25 isn’t even accessible to PRU1 at all. it would have to be on PRU2.

But I will admit, compiling it somehow works and it blinks. This is all done on the 4.14 image.

I moved to the latest nightly builds which don’t have the cloud9 stuff but rather vscode. The example no longer works however got it to compile. I assume this is something due to the beaglebone-ai.dts changing over time.

Am I completely missing some core concept?

there is no PRU2. According to documentation that you cited, P9_25 is on PRU1 of PRU-ICSS2.

Assume that the SRM is correct … 6.12.5 PRU-ICSS2 Pin Access

this section has 3 hits for P9_25:

  • pr2_pru1_gpo5
  • pr2_pru1_gpi5
  • pr2_mii1_col

if you accept their naming convention, P9_25 is on ‘pr2’ NOT ‘PRU2’. more specifically, it is on PRU1 of PR2.

(I think that) The cloud9 file (comment) may need to be updated.

I suspect that close examination of this file will be more accurate than the comments.

good luck

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Ah thanks so much. I was jumping to my own wrong conclusion on the naming convention of the PRU vs PR which you have cleared up.

Really though was just staring too long thank you!