AnalogIn.h

00001 /* mbed Microcontroller Library - AnalogIn
00002  * Copyright (c) 2006-2011 ARM Limited. All rights reserved.
00003  */ 
00004 
00005 #ifndef MBED_ANALOGIN_H
00006 #define MBED_ANALOGIN_H
00007 
00008 #include "device.h"
00009 
00010 #if DEVICE_ANALOGIN
00011 
00012 #include "platform.h"
00013 #include "PinNames.h"
00014 #include "PeripheralNames.h"
00015 #include "Base.h"
00016 
00017 namespace mbed {
00018 
00019 /** An analog input, used for reading the voltage on a pin 
00020  *
00021  * Example:
00022  * @code
00023  * // Print messages when the AnalogIn is greater than 50%
00024  * 
00025  * #include "mbed.h"
00026  * 
00027  * AnalogIn temperature(p20);
00028  * 
00029  * int main() {
00030  *     while(1) {
00031  *         if(temperature > 0.5) {
00032  *             printf("Too hot! (%f)", temperature.read());             
00033  *         }
00034  *     }
00035  * }
00036  * @endcode
00037  */
00038 class AnalogIn :  public Base {
00039 
00040 public:
00041 
00042     /** Create an AnalogIn, connected to the specified pin
00043      *
00044      * @param pin AnalogIn pin to connect to 
00045      * @param name (optional) A string to identify the object
00046      */
00047     AnalogIn(PinName pin, const char *name = NULL);
00048     
00049     /** Read the input voltage, represented as a float in the range [0.0, 1.0]
00050      *
00051      * @returns A floating-point value representing the current input voltage, measured as a percentage
00052      */
00053     float read();    
00054 
00055     /** Read the input voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
00056      *
00057      * @returns
00058      *   16-bit unsigned short representing the current input voltage, normalised to a 16-bit value 
00059      */
00060     unsigned short read_u16();
00061 
00062 #ifdef MBED_OPERATORS
00063     /** An operator shorthand for read()
00064      *
00065      * The float() operator can be used as a shorthand for read() to simplify common code sequences
00066      *
00067      * Example:
00068      * @code
00069      * float x = volume.read();
00070      * float x = volume;
00071      * 
00072      * if(volume.read() > 0.25) { ... }
00073      * if(volume > 0.25) { ... }
00074      * @endcode
00075      */
00076     operator float();
00077 #endif
00078 
00079 #ifdef MBED_RPC
00080     virtual const struct rpc_method *get_rpc_methods();
00081     static struct rpc_class *get_rpc_class();
00082 #endif
00083 
00084 protected:
00085 
00086     ADCName _adc;
00087     
00088 };
00089 
00090 } // namespace mbed
00091 
00092 #endif
00093 
00094 #endif