Diff: cpp/AnalogOut.h

Revision:

0:fd0d7bdfcdc2

Child:

2:143cac498751

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cpp/AnalogOut.h	Tue Nov 20 17:24:08 2012 +0000
@@ -0,0 +1,127 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2012 ARM Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef MBED_ANALOGOUT_H
+#define MBED_ANALOGOUT_H
+
+#include "platform.h"
+
+#if DEVICE_ANALOGOUT
+
+#include "analogout_api.h"
+
+namespace mbed {
+
+/** An analog output, used for setting the voltage on a pin
+ *
+ * Example:
+ * @code
+ * // Make a sawtooth output
+ *  
+ * #include "mbed.h"
+ *  
+ * AnalogOut tri(p18);
+ * int main() {
+ *     while(1) {
+ *         tri = tri + 0.01;
+ *         wait_us(1);
+ *         if(tri == 1) {
+ *             tri = 0;
+ *         }
+ *     }
+ * }
+ * @endcode
+ */
+class AnalogOut {
+
+public:
+
+    /** Create an AnalogOut connected to the specified pin
+     * 
+     *  @param AnalogOut pin to connect to (18)
+     */
+    AnalogOut(PinName pin) {
+        analogout_init(&_dac, pin);
+    }
+    
+    /** Set the output voltage, specified as a percentage (float)
+     *
+     *  @param value A floating-point value representing the output voltage, 
+     *    specified as a percentage. The value should lie between
+     *    0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
+     *    Values outside this range will be saturated to 0.0f or 1.0f.
+     */
+    void write(float value) {
+        analogout_write(&_dac, value);
+    }
+    
+    /** Set the output voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
+     *
+     *  @param value 16-bit unsigned short representing the output voltage,
+     *            normalised to a 16-bit value (0x0000 = 0v, 0xFFFF = 3.3v)
+     */
+    void write_u16(unsigned short value) {
+        analogout_write_u16(&_dac, value);
+    }
+
+    /** Return the current output voltage setting, measured as a percentage (float)
+     *
+     *  @returns
+     *    A floating-point value representing the current voltage being output on the pin, 
+     *    measured as a percentage. The returned value will lie between
+     *    0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
+     *
+     *  @note
+     *    This value may not match exactly the value set by a previous write().
+     */
+    float read() {
+        return analogout_read(&_dac);
+    }
+
+#ifdef MBED_OPERATORS
+    /** An operator shorthand for write()
+     */
+    AnalogOut& operator= (float percent) {
+        write(percent);
+        return *this;
+    }
+    
+    AnalogOut& operator= (AnalogOut& rhs) {
+        write(rhs.read());
+        return *this;
+    }
+
+    /** An operator shorthand for read()
+     */
+    operator float() {
+        return read();
+    }
+#endif
+
+protected:
+    dac_t _dac;
+};
+
+} // namespace mbed
+
+#endif
+
+#endif