Diff: DebounceIn.cpp

Revision:

0:e43521d55082

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DebounceIn.cpp	Sun Dec 20 12:04:08 2015 +0000
@@ -0,0 +1,62 @@
+/* A digital input with switch debouncing
+ * Copyright 2015, Takuo Watanabe
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "DebounceIn.h"
+
+DebounceIn::DebounceIn(PinName pin, timestamp_t us) : DigitalIn(pin) {
+    _prev = _curr = 0;
+    _rise = _fall = NULL;
+    set_sample_rate(us);
+}
+
+DebounceIn::~DebounceIn() {
+    _ticker.detach();
+}
+
+int DebounceIn::read() {
+    return _curr;
+}
+
+#ifdef MBED_OPERATORS
+    /** An operator shorthand for read()
+     */
+    DebounceIn::operator int() {
+        return read();
+    }
+#endif
+
+void DebounceIn::set_sample_rate(timestamp_t us) {
+    _ticker.detach();
+    _ticker.attach_us(this, &DebounceIn::sample, us);
+}
+
+void DebounceIn::rise(void (*fptr)(void)) {
+    _rise.attach(fptr);
+}
+
+void DebounceIn::fall(void (*fptr)(void)) {
+    _fall.attach(fptr);
+}
+
+void DebounceIn::sample() {
+    int now = DigitalIn::read();
+    if (now == _prev) {
+        if (!_curr && now) _rise.call();
+        if (_curr && !now) _fall.call();
+        _curr = now;
+    }
+    _prev = now;
+}