Hi Jacek,
On Mon, Sep 7, 2015 at 3:03 PM, Jacek Anaszewski
<[email protected]> 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
> construct it without additional GPIO driven transistor?
Perhaps just like this?
VCC
|
R
|
|
_|_
\ /
---
|
|
GPIO -----R-----------+
|
|
| o
-|
| o
|
|
GND
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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