add class for handling button events - signals main thread when event occurs and main thread can check event - supports SW1 press, SW2 press, and SW1 hold

2 files changed, 81 insertions, 0 deletions

diff --git a/ButtonHandler/ButtonHandler.cpp b/ButtonHandler/ButtonHandler.cpp
new file mode 100644
index 0000000..23bcb02
--- /dev/null
+++ b/ButtonHandler/ButtonHandler.cpp
@@ -0,0 +1,45 @@
+#include "ButtonHandler.h"
+
+ButtonHandler::ButtonHandler(osThreadId main)
+  : _main(main),
+    _sw1(PA_12),
+    _sw2(PA_11),
+    _sw1_time(0),
+    _event(none)
+{
+    // gpio goes low when push button is pressed
+    // fall handler will be the press, rise handler will be the release
+    _sw1.fall(this, &ButtonHandler::sw1_fall);
+    _sw1.rise(this, &ButtonHandler::sw1_rise);
+    // need to set mode to PullUp after attaching handlers - won't work otherwise
+    _sw1.mode(PullUp);
+
+    _sw2.fall(this, &ButtonHandler::sw2_fall);
+    _sw2.mode(PullUp);
+}
+
+ButtonEvent ButtonHandler::getButtonEvent() {
+    ButtonEvent event = _event;
+    _event = none;
+    return event;
+}
+
+void ButtonHandler::sw1_rise() {
+    _sw1_timer.stop();
+    _sw1_time = _sw1_timer.read_ms();
+
+    if (_sw1_time > 10) {
+        _event = (_sw1_time > 500) ? sw1_hold : sw1_press;
+        osSignalSet(_main, buttonSignal);
+    }
+}
+
+void ButtonHandler::sw1_fall() {
+    _sw1_timer.reset();
+    _sw1_timer.start();
+}
+
+void ButtonHandler::sw2_fall() {
+    _event = sw2_press;
+    osSignalSet(_main, buttonSignal);
+}
diff --git a/ButtonHandler/ButtonHandler.h b/ButtonHandler/ButtonHandler.h
new file mode 100644
index 0000000..3eb8298
--- /dev/null
+++ b/ButtonHandler/ButtonHandler.h
@@ -0,0 +1,36 @@
+#ifndef __BUTTONHANDLER_H__
+#define __BUTTONHANDLER_H__
+
+#include "mbed.h"
+#include "rtos.h"
+
+#define buttonSignal (uint32_t)0x01
+
+typedef enum {
+    none = 0,
+    sw1_press,
+    sw1_hold,
+    sw2_press
+} ButtonEvent;
+
+class ButtonHandler {
+    public:
+        ButtonHandler(osThreadId main);
+        ~ButtonHandler();
+
+        ButtonEvent getButtonEvent();
+
+    private:
+        void sw1_fall();
+        void sw1_rise();
+        void sw2_fall();
+
+        osThreadId _main;
+        InterruptIn _sw1;
+        InterruptIn _sw2;
+        Timer _sw1_timer;
+        time_t _sw1_time;
+        ButtonEvent _event;
+};
+
+#endif