On 26.04.19 19:20, Andy Shevchenko wrote:
On Fri, Apr 26, 2019 at 7:05 PM Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
On 26.04.19 16:42, Enrico Weigelt, metux IT consult wrote:
On 26.04.19 15:36, Jan Kiszka wrote:
At the same time, there are no real alternatives - to my> knowledge - for the value it brings (various bindings) to simply
switch> the engine.
Which value exactly does that collection of crude wrappers and broken
attempts to buypass the kernel (driving gpios via /dev/mem *facepalm*)
provide ?
Leaving that blunt hack aside:
import mraa
pin = mraa.Gpio(13)
pin.dir(mraa.DIR_OUT)
pin.write(1)
And the same goes for nodejs, java and c++.
Moreover, this allows you to abstract away where "Pin 13" actually came from on
that board if the kernel changes (BSP -> upstream...) or the extension board or
...
The problem here is opaque number. This has to be chip + *relative* pin number/
See this:
https://stackoverflow.com/questions/55532410/how-do-linux-gpio-numbers-get-their-values/55579640#55579640
...and device path based discovery of the base:
https://github.com/siemens/mraa/commits/jan/queue
And I think that makes good use cases for application-level abstractions like in
mraa. You don't want all user having to learn those nasty details, for
devicetree, ACPI, and even worse stuff.
Jan
--
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux
