Wiadomość napisana przez Bakul Shah <ba...@bitblocks.com> w dniu 10 maj 2014, o godz. 01:21:
> On Fri, 09 May 2014 16:11:00 +0200 Krystian Lewandowski > <krystian....@gmail.com> wrote: >> >> I was working on GPIO under Plan9 - very simple thing but also supports >> edge-raising/falling events. I had simple C code to print what pin >> triggered an event. I'll try to push this simple test to github during >> weekend. Though i'm not sure how it can be integrated - is events counting >> enough? > > I think for a rotary encoder you'd want to know about every > transition. One idea is to return 1/0 on a up/down transition > to a blocking read. Let the user re-enable the corresponding > interrupt by writing 1 to the same fd. > > The user code reads from two pins and figures out which way > the knob is turning. Similarly you can have user code count > events if that is what you want. > Hi, i’ve added a simple edge events listener test. The test reads 32 bits from #G/gpio/event where each bit position corresponds to „bcm” naming scheme, so bit 17 means GPIO0 (was easier this way). #G/gpio/event blocks on read, while #G/gpio/GPIO0 does not - just returns current value (and there is no need to seek to beginning). Works with a single button. ;) https://github.com/elewarr/gpio_test/blob/master/events.c cpu% ./events 1: pin 17, state changed GPIO0 state=0 2: pin 17, state changed GPIO0 state=1 3: pin 17, state changed GPIO0 state=0 4: pin 17, state changed GPIO0 state=1 Cheers, Krystian
