Read GPIO problem
#11
(08-07-2017, 07:21 AM)MarkHaysHarris777 Wrote: Note:  I do understand 'what' everyone believes export "should" accomplish, and I certainly also believe that it should be possible to guarantee the default operation of an exported pad;  however, my personal 'reality' is that it is more important to help users understand the complete operation rather than arguing over what 'should' be happening.  At the end of the day, do you want the pad to work or not ??  That's the simple question you need to answer for yourself.

Um, don't you mean you understand what export DOES on the board that people are most familiar with this funtionality? Because on the raspberry pi, there is no need to set the direction, because the initial sysfs values are correct!! Tongue When you export a pin, and then do a 'cat /sys/kernel/debug/gpio' on the rPi, the values you see are actually representational of the pin state, not false (i.e. gpio-4 sysfs in lo).

However, when you move to other boards, such as the Orange Pi Zero, you are out of luck... they are left floating just like with the pine64. Yes, it is nice to have it working, but exceptionalism is not good either... because this means this is yet another thing that makes the RPi-2 bus not RPi-2 compatible. So at the end of the day, I would like to either make it do what everyone expects it to do, or if that is not possible, document it as a known issue, because it is not rPi behaviour. Anything else is just looking at it with rose-tinted glasses, and making excuses.
  Reply


Messages In This Thread
Read GPIO problem - by shworker - 02-21-2017, 04:00 AM
RE: Read GPIO problem - by Techsensei - 02-21-2017, 06:41 AM
RE: Read GPIO problem - by shworker - 02-21-2017, 08:58 AM
RE: Read GPIO problem - by MarkHaysHarris777 - 02-22-2017, 04:23 AM
RE: Read GPIO problem - by aromring - 08-05-2017, 09:59 PM
RE: Read GPIO problem - by MarkHaysHarris777 - 08-05-2017, 10:24 PM
RE: Read GPIO problem - by pfeerick - 08-06-2017, 01:33 AM
RE: Read GPIO problem - by MarkHaysHarris777 - 08-06-2017, 10:38 AM
RE: Read GPIO problem - by pfeerick - 08-07-2017, 12:11 AM
RE: Read GPIO problem - by MarkHaysHarris777 - 08-07-2017, 07:21 AM
RE: Read GPIO problem - by pfeerick - 08-07-2017, 07:21 PM
RE: Read GPIO problem - by MarkHaysHarris777 - 08-07-2017, 11:10 PM
RE: Read GPIO problem - by pfeerick - 08-08-2017, 06:20 PM
RE: Read GPIO problem - by MarkHaysHarris777 - 08-15-2017, 02:24 AM
RE: Read GPIO problem - by martinayotte - 08-17-2017, 01:21 PM

Possibly Related Threads…
Thread Author Replies Views Last Post
  RPi.GPIO python module for Pine A64/A64+ aquilegia 98 133,202 12-15-2022, 08:40 PM
Last Post: Fadazo
  fm transmitter with gpio weasel18 2 4,880 09-10-2019, 04:28 AM
Last Post: desai_amogh
  How to use dts or other setup to declare gpio pin Interrupt (e.g. a button)? dkebler 1 3,630 06-12-2019, 10:37 AM
Last Post: dkebler
Lightbulb Sample GPIO codes highlighting RPi.GPIO-PineA64 and the PI bus MarkHaysHarris777 6 11,229 06-07-2019, 12:37 AM
Last Post: tllim
Star GPIO, SPI and I2C C++ Lib databit 7 11,325 02-04-2019, 05:45 AM
Last Post: Jeff R
Information Howto: Controlling Pine64 GPIO via the filesystem (sysfs) on linux pfeerick 4 11,943 01-24-2019, 03:36 AM
Last Post: Fifth
  GPIO and SPI SamR1 20 31,917 03-15-2018, 10:32 AM
Last Post: jomoengineer
Question GPIO shockr 7 14,892 03-11-2018, 01:52 AM
Last Post: jomoengineer
  GPIO fiq capability joseph 3 6,160 11-10-2016, 06:07 PM
Last Post: joseph
  RPI2-GPIO mus1c 6 9,184 09-22-2016, 05:28 AM
Last Post: mus1c

Forum Jump:


Users browsing this thread: 1 Guest(s)