Jim Flynn
Implementation of a button class and test program
Revision 0:377a50b631cf, committed 2018-08-30
- Comitter:
- JMF
- Date:
- Thu Aug 30 00:35:30 2018 +0000
- Child:
- 1:c668e9604e63
- Commit message:
- button class example
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Button.hpp Thu Aug 30 00:35:30 2018 +0000
@@ -0,0 +1,75 @@
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+#include "mbed.h"
+
+#define BUTTON_DEBOUNCE 20
+
+class Button {
+ protected:
+ InterruptIn user_button;
+ void (*br_cb)(int);
+ void (*bp_cb)(void);
+
+ Thread button_thread;
+ void button_monitor_task(void);
+ EventQueue button_queue;
+ uint64_t bp_time, bp_duration;
+ int button_pressed;
+
+ void button_press_handler(void) {
+ if( (rtos::Kernel::get_ms_count() - bp_time) < BUTTON_DEBOUNCE)
+ return;
+ bp_time = rtos::Kernel::get_ms_count();
+ if( bp_cb )
+ bp_cb();
+ }
+
+ void button_release_handler(void) {
+ uint64_t tmp = rtos::Kernel::get_ms_count() - bp_time;
+ if( tmp > BUTTON_DEBOUNCE ) {
+ bp_duration = tmp;
+ button_pressed++;
+ if( br_cb )
+ br_cb(bp_duration);
+ }
+ }
+
+ public:
+ enum State { ActiveHigh = 0, ActiveLow };
+
+ Button(PinName p, State s, void (*cb)(int)=NULL) :
+ user_button(p),
+ br_cb(cb),
+ bp_cb(NULL),
+ bp_time(0),
+ bp_duration(0),
+ button_pressed(0)
+ {
+ // The user button is active low so setup the falling edge to generate
+ // an interrupt. Catch the release with an event queue event
+ button_thread.start(callback(&button_queue, &EventQueue::dispatch_forever));
+ if( s == ActiveHigh ) {
+ user_button.rise( Callback<void()>(this, &Button::button_press_handler) );
+ user_button.fall( button_queue.event( Callback<void()>(this, &Button::button_release_handler)));
+ }
+ else{
+ user_button.fall( Callback<void()>(this, &Button::button_press_handler) );
+ user_button.rise(button_queue.event(Callback<void()>(this, &Button::button_release_handler)));
+ }
+ }
+
+ int chkButton_press(int *duration) {
+ int bp = button_pressed;
+
+ if( button_pressed ) {
+ *duration = bp_duration;
+ bp_duration = 0;
+ button_pressed = 0;
+ }
+ return bp;
+ }
+
+ void setButton_press_cb( void (*buttonpresscb)(void) ) {
+ bp_cb = buttonpresscb;
+ }
+};
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Thu Aug 30 00:35:30 2018 +0000
@@ -0,0 +1,43 @@
+#include "mbed.h"
+#include "Button.hpp"
+
+void br_callback(int dur)
+{
+ printf("\r\n!! button RELEASE called, press time: %d msec\r\n", dur);
+}
+
+void bp_callback(void)
+{
+ printf("\r\n!! button PRESS called\r\n");
+}
+
+int main() {
+ int k, dur;
+ Button* button_ptr;
+
+ printf("Testing button class\r\n");
+ printf("Test Standard polling type implementation\r\n");
+ button_ptr = new Button(USER_BUTTON, Button::ActiveHigh);
+ while( (k=button_ptr->chkButton_press(&dur)) == 0 )
+ /* wait */;
+ printf(">Button pressed %d times, last was %d msec\r\n",k,dur);
+ delete button_ptr;
+
+ printf("\nTest with Release callback\r\n");
+ button_ptr = new Button(USER_BUTTON, Button::ActiveHigh, br_callback);
+ while( (k=button_ptr->chkButton_press(&dur)) == 0 )
+ /* wait */;
+ printf(">Button pressed %d times, last was %d msec\r\n",k,dur);
+ delete button_ptr;
+
+ printf("\nTest with Press & Release callback\r\n");
+ button_ptr = new Button(USER_BUTTON, Button::ActiveHigh, br_callback);
+ button_ptr->setButton_press_cb(bp_callback);
+ while( (k=button_ptr->chkButton_press(&dur)) == 0 )
+ /* wait */;
+ printf(">Button pressed %d times, last was %d msec\r\n",k,dur);
+ while (1) {
+ wait(.5);
+ }
+
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed-os.lib Thu Aug 30 00:35:30 2018 +0000 @@ -0,0 +1,1 @@ +https://github.com/ARMmbed/mbed-os/#f8b140f8d7cb226e41486c5df66ac4f3ce699219