If you all prefer that I write separate threads on each question, please let me know and I will do so:
I am using I am working with BBB Bullseye XFCE image 2023-05-03
Also, noted that BB uses Adafruit-GPIO library by default which appears active by default.
1: Calling GPIO’s by PIN # or GPIO#
- is it arbitrary, or does the python prgram specify which way to go?
2. i2c
- Does it have to be activated somewhere? If so, where.
- it appears to use pins P9-18 and 19
3. HDMI - I read in GPIO documentation that it takes up GPIO’s, but does not mention which ones
4- 1-wire - is it present
- if so where, and which GPIO does it occupy?
TY all in advance,
I believe there are two I2C buses. One uses P9.19 and P9.20, the other looks like P9.17 and P9.18. To use those pins as I2C buses use config-pin:
config-pin P9.19 i2c
config-pin P9.20 i2c
Look at the PDF for the P8 header above to see which pins are used by HDMI. To disable HDMI and have access to those pins for GPIO or other functionality you’ll need to edit your /boot/uEnv.txt. Uncomment these lines to have access to all the HDMI pins:
disable_uboot_overlay_video=1
disable_uboot_overlay_audio=1
TY kindly for your answers and links!!
So, it does answer my question about where the HDMI pins are located (which I do not want to disable, I just want to make sure I don’t use those GPIO’s). It also show which other (Misot?) GLIO’s are taken up by other ‘things’. Good to know.
Would it be OK to still ask the remaining questions:
1: Calling GPIO’s by PIN # or GPIO#
is it arbitrary, or does the python prgram specify which way to go?
i2c
Does it have to be activated somewhere? If so, where.
it appears to use pins P9-17and 198 for i2c1 and 19-20 for i2c2 as you described above
3- 1-wire - is it present
When you design your PCB you’re seeing the header pins. Why should anybody transfer to GPIO#? And even the GPIO# isn’t interesting, instead only CPU ball# is of interest.
You can find infos on the GPIO header pins (free or claimed) at libpruio: Pins
There’s a W1 driver in the kernel, but it allows only one device on the bus. That’s why I wrote a flexible driver to connect an unlimited number of devices. That driver can work on any GPIO (even on the pins in SD-Card-Slot). It also allows to sniff the line in order to track wiring issues.
DRJF,
TY for your considerate answers!
But, firstly - I really do want to call the GPIO’s by there GPIO number, not pin number. Reason: The python programs I have written all call for them, and, when converting the code to BBB board, I can make a config file with variables switching from the RPi GPIO’s to the BBB GPIO;s. I don’t want to mix the pins and GPIO #'s.
So, I went through the linked document and nothing told me if the program has to designate using Pin#'s or GPIO #
Secondly, TY for 1-Wire answer, and I only need one attachment and one bus (using 18B20 temp sensors), so, the W1 driver would be great. I am confused if the link you provided is the actual driver in the kernel, or some other project?
Q: How do I access this W1 Driver (I am VERY new to BBB).
So I still have 3 remaining questions:
1: Calling GPIO’s by PIN # or GPIO#
is it arbitrary, or does the python prgram specify which way to go?
2: i2c
Does it have to be activated somewhere? If so, where.
it appears to use pins P9-17and 198 for i2c1 and 19-20 for i2c2 as you described above
3- 1-wire - is it present
if so where, and which GPIO does it occupy? How is the Kernel driver utilized?
If you want to control or read from specific GPIOs by number rather than the pin numbers documented on the Beaglebone, you may want to go with using libgpiod or something like that. Then you can control them directly through their GPIO chip and line number. I’ve never tried it, but it looks like there may be python bindings that use it: Python gpiod | loliot by HHK
TY for that!
Remaining:
1: i2c
Does it have to be activated somewhere? If so, where.
it appears to use pins P9-17and 18 for i2c1 and 19-20 for i2c2 as you described above
2- 1-wire - is it present
if so where, and which GPIO does it occupy? How is the Kernel driver utilized?