Diff: mbed/drivers/AnalogIn.h

Revision:

6:40e873bbc5f7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed/drivers/AnalogIn.h	Thu Mar 16 21:58:09 2017 +0900
@@ -0,0 +1,132 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * 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 MBED_ANALOGIN_H
+#define MBED_ANALOGIN_H
+
+#include "platform/platform.h"
+
+#if DEVICE_ANALOGIN
+
+#include "hal/analogin_api.h"
+#include "platform/SingletonPtr.h"
+#include "platform/PlatformMutex.h"
+
+namespace mbed {
+/** \addtogroup drivers */
+/** @{*/
+
+/** An analog input, used for reading the voltage on a pin
+ *
+ * @Note Synchronization level: Thread safe
+ *
+ * Example:
+ * @code
+ * // Print messages when the AnalogIn is greater than 50%
+ *
+ * #include "mbed.h"
+ *
+ * AnalogIn temperature(p20);
+ *
+ * int main() {
+ *     while(1) {
+ *         if(temperature > 0.5) {
+ *             printf("Too hot! (%f)", temperature.read());
+ *         }
+ *     }
+ * }
+ * @endcode
+ */
+class AnalogIn {
+
+public:
+
+    /** Create an AnalogIn, connected to the specified pin
+     *
+     * @param pin AnalogIn pin to connect to
+     * @param name (optional) A string to identify the object
+     */
+    AnalogIn(PinName pin) {
+        lock();
+        analogin_init(&_adc, pin);
+        unlock();
+    }
+
+    /** Read the input voltage, represented as a float in the range [0.0, 1.0]
+     *
+     * @returns A floating-point value representing the current input voltage, measured as a percentage
+     */
+    float read() {
+        lock();
+        float ret = analogin_read(&_adc);
+        unlock();
+        return ret;
+    }
+
+    /** Read the input voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
+     *
+     * @returns
+     *   16-bit unsigned short representing the current input voltage, normalised to a 16-bit value
+     */
+    unsigned short read_u16() {
+        lock();
+        unsigned short ret = analogin_read_u16(&_adc);
+        unlock();
+        return ret;
+    }
+
+    /** An operator shorthand for read()
+     *
+     * The float() operator can be used as a shorthand for read() to simplify common code sequences
+     *
+     * Example:
+     * @code
+     * float x = volume.read();
+     * float x = volume;
+     *
+     * if(volume.read() > 0.25) { ... }
+     * if(volume > 0.25) { ... }
+     * @endcode
+     */
+    operator float() {
+        // Underlying call is thread safe
+        return read();
+    }
+
+    virtual ~AnalogIn() {
+        // Do nothing
+    }
+
+protected:
+
+    virtual void lock() {
+        _mutex->lock();
+    }
+
+    virtual void unlock() {
+        _mutex->unlock();
+    }
+
+    analogin_t _adc;
+    static SingletonPtr<PlatformMutex> _mutex;
+};
+
+} // namespace mbed
+
+#endif
+
+#endif
+
+/** @}*/