Are there button libraries available for use on STM32 MCUs?

[lightaiyee]

Posted on January 06, 2015 at 11:01

I am a newbie to STM32. I would like to migrate existing solution to STM32 which uses a button library that can detect double-press, triple-press, long-press, very-long-press etc.

Is there a button library available for the STM32 platform that I can use?Thank you very much.

[Tamas Novak]

Posted on January 06, 2015 at 13:09

I have never seen a library like that, but it could be written quite easily.

My usual pushbutton filtering code is

//Key is pressed when ''Keyfilter'' goes up to 10, and released if counts down to 0. Counting +/-1  happens at every 1 msec.

#define KEY_FILTER_MAX    10 if (GPIO_ReadInputDataBit (<port, bit>)==0) {     Keyfilter++;     } else {     Keyfilter--;     } if (Keyfilter < 0) {     Keyfilter= 0;    //stuck at lower limit     } if (Keyfilter > KEY_FILTER_MAX) {     Keyfilter= KEY_FILTER_MAX;    //limit at max value     } if ((Keyfilter == 0) && (KeyServiced != 0))    { //if it have been reported, but not held down any more, we do service for release     KeyServiced= 0;     KeyReleaseService();     } if ((Keyfilter == KEY_FILTER_MAX) && (KeyServiced == 0)) {    //it is pushed but not serviced yet     KeyPressTime= T_msec;         KeyServiced= 1;     KeyPressService();     } } If you push key-state-change-times into an array of 6 element (oldest item is to be shifted out: last 6 up/down times are stored), you can detect double/triple strokes: I evaluate buffer if last pushed item is a release event. At evaluate function - I check the time difference of the actual release and the previous down event. If it is shorter than 10msec, it's a glitch only. If it is 10msec..0.5sec, then normal push, if >0.5sec then a long push. - I check the time and duration of [last-2] and [last-3] element pair...if they are older than 1sec, then they are part of a different sequence...if newer than 1sec, it's double (or triple) press ..and so on...