gcc4mbed/external/mbed/.svn/text-base/AnalogOut.h.svn-base

   1 /* mbed Microcontroller Library - AnalogOut
   2  * Copyright (c) 2006-2009 ARM Limited. All rights reserved.
   3  * sford
   4  */
   5
   6 #ifndef MBED_ANALOGOUT_H
   7 #define MBED_ANALOGOUT_H
   8
   9 #include "platform.h"
  10 #include "PinNames.h"
  11 #include "PeripheralNames.h"
  12 #include "Base.h"
  13
  14 namespace mbed {
  15
  16 /* Class: AnalogOut
  17  *  An analog output, used for setting the voltage on a pin
  18  *
  19  * Example:
  20  * > // Make a sawtooth output
  21  * >
  22  * > #include "mbed.h"
  23  * >
  24  * > AnalogOut tri(p18);
  25  * > int main() {
  26  * >     while(1) {
  27  * >         tri = tri + 0.01;
  28  * >         wait_us(1);
  29  * >         if(tri == 1) {
  30  * >             tri = 0;
  31  * >         }
  32  * >     }
  33  * > }
  34  */
  35 class AnalogOut : public Base {
  36
  37 public:
  38
  39         /* Constructor: AnalogOut
  40          *  Create an AnalogOut connected to the specified pin
  41          *
  42          * Variables:
  43          *  pin - AnalogOut pin to connect to (18)
  44          */
  45         AnalogOut(PinName pin, const char *name = NULL);
  46
  47     /* Function: write
  48      *  Set the output voltage, specified as a percentage (float)
  49      *
  50      * Variables:
  51      *  percent - A floating-point value representing the output voltage,
  52      *    specified as a percentage. The value should lie between
  53      *    0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
  54      *    Values outside this range will be saturated to 0.0f or 1.0f.
  55      */
  56     void write(float value);
  57
  58     /* Function: write_u16
  59      *  Set the output voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
  60      *
  61      * Variables:
  62      *  value - 16-bit unsigned short representing the output voltage,
  63      *            normalised to a 16-bit value (0x0000 = 0v, 0xFFFF = 3.3v)
  64      */
  65     void write_u16(unsigned short value);
  66
  67     /* Function: read
  68      *  Return the current output voltage setting, measured as a percentage (float)
  69      *
  70      * Variables:
  71      *  returns - A floating-point value representing the current voltage being output on the pin,
  72      *    measured as a percentage. The returned value will lie between
  73      *    0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
  74      *
  75      * Note:
  76      *  This value may not match exactly the value set by a previous <write>.
  77      */
  78     float read();
  79
  80
  81 #ifdef MBED_OPERATORS
  82     /* Function: operator=
  83      *  An operator shorthand for <write()>
  84      */
  85         AnalogOut& operator= (float percent);
  86         AnalogOut& operator= (AnalogOut& rhs);
  87
  88     /* Function: operator float()
  89      *  An operator shorthand for <read()>
  90      */
  91         operator float();
  92 #endif
  93
  94 #ifdef MBED_RPC
  95     virtual const struct rpc_method *get_rpc_methods();
  96     static struct rpc_class *get_rpc_class();
  97 #endif
  98
  99 protected:
 100
 101         DACName _dac;
 102
 103 };
 104
 105 } // namespace mbed
 106
 107 #endif
 108