Hi Geert,
Thanks for sharing this.
On 09/07/2015 03:22 PM, Geert Uytterhoeven wrote:
Hi Jacek,
On Mon, Sep 7, 2015 at 3:03 PM, Jacek Anaszewski
<j.anaszewski@xxxxxxxxxxx> wrote:
On 09/01/2015 07:00 PM, Geert Uytterhoeven wrote:
I'm wondering if there already exists a driver for a gpio that's connected
to both an LED and an input switch.
I'd expect such a hardware configuration to be fairly common, as gpios can
be
a limited resource.
Most of the time the gpio would be in output mode, driving the LED, but at
regular intervals the mode would be changed for a very short moment to
input,
to monitor the state of the switch.
I had a quick look at various drivers (and of course at
Documentation/gpio/drivers-on-gpio.txt), but couldn't find any.
Does such a hybrid of "leds-gpio" and "gpio-keys(-polled)" already exists?
Can you share an example of such a circuit? Would it be possible to
Something like this?
VCC VCC
| |
R R
| |
__|__ | |
+---o o---+ _|_
| | \ /
| | ---
GND R |
| |
| |-+
| |<+
GPIO -----------------+---------|-|
|
|
GND
You would need also resistor to avoid short-circuit
when the switch is on.
construct it without additional GPIO driven transistor?
Perhaps just like this?
VCC
|
R
|
|
_|_
\ /
---
|
|
GPIO -----R-----------+
|
|
| o
-|
| o
|
|
GND
We'd have to ask Linus if he welcomes drivers for this type
of home-made circuits in mainline. If yes, then probably someone would
have to build the circuit, develop and test the driver on it, and
finally come up with a detailed documentation.
Are you the volunteer? :)
--
Best Regards,
Jacek Anaszewski
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