Elecia White / Mbed 2 deprecated freedom_inertial_hello_world

A hello world for inertial sensors

Dependencies:   FXAS21000 FXOS8700Q mbed

Fork of FRDM-STBC-AGM01 by angus taggart

button.cpp@4:5ab2bb2f062b, 2015-06-30 (annotated)

Committer:
Elecia
Date:
Tue Jun 30 16:23:32 2015 +0000
Revision:
4:5ab2bb2f062b
Parent:
3:123b546e4a5c 
Added element14 link

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Elecia 3:123b546e4a5c 1 #include "button.h"
Elecia 3:123b546e4a5c 2 #include "mbed.h"
Elecia 3:123b546e4a5c 3
Elecia 3:123b546e4a5c 4 #define HIGH 1
Elecia 3:123b546e4a5c 5 #define LOW 0
Elecia 3:123b546e4a5c 6
Elecia 3:123b546e4a5c 7
Elecia 3:123b546e4a5c 8 void initializeButtonDebounce()
Elecia 3:123b546e4a5c 9 {
Elecia 3:123b546e4a5c 10 // possibly start ticker if you want to auto debounce
Elecia 3:123b546e4a5c 11 }
Elecia 3:123b546e4a5c 12
Elecia 3:123b546e4a5c 13 // button press with hysterisis
Elecia 3:123b546e4a5c 14 bool debounceButtonPress(int reading)
Elecia 3:123b546e4a5c 15 {
Elecia 3:123b546e4a5c 16
Elecia 3:123b546e4a5c 17 static int buttonState = HIGH; // the current reading from the input pin
Elecia 3:123b546e4a5c 18 static int lastButtonState = HIGH; // the previous reading from the input pin
Elecia 3:123b546e4a5c 19 static long lastDebounceTime = 0; // the last time the output pin was toggled
Elecia 3:123b546e4a5c 20 const long kDebounceDelay = 3; // the debounce time; increase if the output flickers
Elecia 3:123b546e4a5c 21
Elecia 3:123b546e4a5c 22 lastDebounceTime++;
Elecia 3:123b546e4a5c 23 if (reading != lastButtonState) {
Elecia 3:123b546e4a5c 24 // reset the debouncing timer
Elecia 3:123b546e4a5c 25 lastDebounceTime = 0;
Elecia 3:123b546e4a5c 26 lastButtonState = reading;
Elecia 3:123b546e4a5c 27 }
Elecia 3:123b546e4a5c 28 if (lastDebounceTime >= kDebounceDelay) {
Elecia 3:123b546e4a5c 29 // whatever the reading is at, it's been there for longer
Elecia 3:123b546e4a5c 30 // than the debounce delay, so take it as the actual current state:
Elecia 3:123b546e4a5c 31
Elecia 3:123b546e4a5c 32 // if the button state has changed:
Elecia 3:123b546e4a5c 33 if (reading != buttonState) {
Elecia 3:123b546e4a5c 34 buttonState = reading;
Elecia 3:123b546e4a5c 35
Elecia 3:123b546e4a5c 36 // only indicate button pressed if low, input pulled up and button connects to low
Elecia 3:123b546e4a5c 37 if (buttonState == LOW) {
Elecia 3:123b546e4a5c 38 return true;
Elecia 3:123b546e4a5c 39 }
Elecia 3:123b546e4a5c 40 }
Elecia 3:123b546e4a5c 41 }
Elecia 3:123b546e4a5c 42 return false;
Elecia 3:123b546e4a5c 43 }