Finding good documentation for gpiod

[Chris Green]

I am using the gpiod package for manipulating GPIO inputs/outputs on a
Beaglebone Black SBC (like a Raspberry Pi but with more flexible I/O).

Mostly I am managing to get things to work as I want but better
documentation of gpiod would be a great help.

For example, when one has found an I/O pin (a 'line' in GPIO parlance)
that one wants to use one has to 'request' it using the Line.request()
method.

The help for this is as follows:-

Help on method_descriptor:

request(...)
request(consumer[, type[, flags[, default_val]]]) -> None

Request this GPIO line.

consumer
Name of the consumer.
type
Type of the request.
flags
Other configuration flags.
default_val
Default value of this line.
Note: default_vals argument (sequence of default values passed down to
LineBulk.request()) is still supported for backward compatibility but is
now deprecated when requesting single lines.


Which is pretty good **except** that I can't find a proper description
of the parameters anywhere, i.e. there's nowhere that even tells me
what types of values/objects the parameters are. At the end of the
gpiod.Line section of the help there is this:-

| ACTIVE_HIGH = 1
|
| ACTIVE_LOW = 2
|
| BIAS_AS_IS = 1
|
| BIAS_DISABLE = 2
|
| BIAS_PULL_DOWN = 4
|
| BIAS_PULL_UP = 3
|
| DIRECTION_INPUT = 1
|
| DIRECTION_OUTPUT = 2

Which **might** be appropriate values for 'type' or 'flags' but there
doesn't seem to be any way of knowing.

Am I missing something very obvious somewhere? Is there a 'standard'
way of finding out parameter information?

It may well be that I'm simply banging up against the limit of what
documentation is available, I have managed to get code working OK.
It's just that I'd be happier if I really know what I was doing! :-)



--
Chris Green
·

[Barry]

E

> On 3 Sep 2023, at 22:49, Chris Green via Python-list <pytho...@python.org> wrote:
>
> Mostly I am managing to get things to work as I want but better
> documentation of gpiod would be a great help.

Ask the author? https://github.com/aswild/python-gpiod

Maybe read the source code for hints?

Barry