Beaglebone Black GPIO Mapping

[blucas986]

I am attempting to use a BeagleBone Black (BBB) Wireless A5, and have run into a few minor issues that required steps in addition to the setup instructions on your website. My background is mainly in embedded micro-controllers so I am somewhat new to embedded Linux. I am using Debian GNU/Linux 10 (buster) and have gone through all of the recommended updates/upgrades on Beaglebone website (https://beagleboard.org/upgrade) prior to following your setup instructions (https://github.com/Dan-in-CA/SIP/wiki/installation). Below are some additional steps taken to get sip.py to run smoothly. 

1. "nginx" was using port 80, so I disabled it, which allowed spi.py to load without error and I can now access the SIP's home page in my browser using the IP address of the BBB.
   
2. I was getting a GPIO error and realized Adafruit_BBIO.GPIO was not installed, so I followed the manual install instructions (https://pypi.org/project/Adafruit_BBIO/), which allowed sip.py to load without the GPIO error.
   

My question is how do the pins map between the P1 on the Pi and P9 on the BBB? 

I see the schematic for the Pi on the relay board wiki (https://github.com/KanyonKris/relay_board/wiki), which lines up with the pin mapping shown in gpio_pins.py, but I am having a hard time figuring out which corresponding pins to use on the BBB.  I have already installed the relay board plug-in and it appears to be working correctly from a software perspective.

[dan]

I am not familiar with the model BBB you have but pin mapping is done in the gpio_pins.py file in the SIP folder.

The relay_board plugin is designed to work only on a Pi. You should be able to modify it to work on the BBB by editing the pin assignments in the relay_board.py file.

There are two numbering systems use for the Pi. One is BMC numbering which is based on the processor pin numbering.
The other is board numbering which is based on the physical pin locations on the board.
You can see both using the reference:
https://pinout.xyz/#

The code in gpio_pins.py produces the following pin list for the BBB:
[None, None, None, None, None, None, None, None, None, None, None, 'P9_11', 'P9_12', 'P9_13', 'P9_14', 'P9_15', 'P9_16']

This would be consistent with Pi board numbering.

You might also take a look at the relay_16 plugin witch uses a different pin layout.

Hope this helps.

Dan