Diff: DebounceIn.h

Revision:

0:e43521d55082

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DebounceIn.h	Sun Dec 20 12:04:08 2015 +0000
@@ -0,0 +1,112 @@
+/* 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.
+ */
+
+#ifndef DEBOUNCEIN_H_
+#define DEBOUNCEIN_H_
+
+#include "mbed.h"
+
+/** A digital input with switch debouncing
+ *
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "DebounceIn.h"
+ *
+ * int nrise = 0, nfall = 0;
+ * void rise() { nrise++; }
+ * void fall() { nfall++; }
+ *
+ * int main() {
+ *     DebounceIn button(p14);
+ *     button.rise(rise);
+ *     button.fall(fall);
+ *     while (true) {
+ *         printf("nrise=%d, nfall=%d\n", nrise, nfall);
+ *         wait(1);
+ *     }
+ * }
+ * @endcode
+ */
+class DebounceIn: public mbed::DigitalIn {
+public:
+    /** Create a DebounceIn object connected to the specified pin
+     *
+     * @param pin  DebounceIn pin to connect to
+     * @param us   Input sampling rate (default 1000 microseconds)
+     */
+    DebounceIn(PinName pin, timestamp_t us = 1000);
+
+    virtual ~DebounceIn();
+
+    /** Set the input sampling rate
+     *
+     * @param us  Input sampling rate
+     */
+    void set_sample_rate(timestamp_t us);
+
+    /** Read the input, represented as 0 or 1 (int)
+     *
+     * @returns  An integer representing the state of the input pin
+     */
+    int read(void);
+
+#ifdef MBED_OPERATORS
+    /** An operator shorthand for read()
+     */
+    operator int();
+#endif
+
+    /** Attach a function to call when a rising edge occurs on the input
+     *
+     * @param fptr pointer to a void function, or 0 to set as none
+     */
+    void rise(void (*fptr)(void));
+
+    /** Attach a member function to call when a rising edge occurs on the input
+     *
+     *  @param tptr pointer to the object to call the member function on
+     *  @param mptr pointer to the member function to be called
+     */
+    template<typename T>
+    void rise(T* tptr, void (T::*mptr)(void)) {
+        _rise.attach(tptr, mptr);
+    }
+
+    /** Attach a function to call when a falling edge occurs on the input
+     *
+     *  @param fptr pointer to a void function, or 0 to set as none
+     */
+    void fall(void (*fptr)(void));
+
+    /** Attach a member function to call when a falling edge occurs on the input
+     *
+     *  @param tptr pointer to the object to call the member function on
+     *  @param mptr pointer to the member function to be called
+     */
+    template<typename T>
+    void fall(T* tptr, void (T::*mptr)(void)) {
+        _fall.attach(tptr, mptr);
+    }
+
+private:
+    Ticker _ticker;
+    int _prev, _curr;
+    FunctionPointer _rise, _fall;
+    void sample(void);
+};
+
+#endif /* DEBOUNCEIN_H_ */