audio_FFT

Published 21 Mar 2010, by James Cobb
adc, audio, FFT, sound
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adc.h

00001 /* mbed Library - ADC
00002  * Copyright (c) 2010, sblandford
00003  * released under MIT license http://mbed.org/licence/mit
00004  */
00005 
00006 #ifndef MBED_ADC_H
00007 #define MBED_ADC_H
00008  
00009 #include "mbed.h"
00010 #define XTAL_FREQ       12000000
00011 #define MAX_ADC_CLOCK   13000000
00012 #define CLKS_PER_SAMPLE 64
00013 
00014 class ADC {
00015 public:
00016 
00017     //Initialize ADC with ADC maximum sample rate of
00018     //sample_rate and system clock divider of cclk_div
00019     //Maximum recommened sample rate is 184000
00020     ADC(int sample_rate, int cclk_div);
00021 
00022     //Enable/disable ADC on pin according to state
00023     //and also select/de-select for next conversion
00024     void setup(PinName pin, int state);
00025 
00026     //Return enabled/disabled state of ADC on pin
00027     int setup(PinName pin);
00028 
00029     //Enable/disable burst mode according to state
00030     void burst(int state);
00031 
00032     //Select channel already setup
00033     void select(PinName pin);
00034 
00035     //Return burst mode enabled/disabled
00036     int burst(void);
00037 
00038     /*Set start condition and edge according to mode:
00039     0 - No start (this value should be used when clearing PDN to 0).
00040     1 - Start conversion now.
00041     2 - Start conversion when the edge selected by bit 27 occurs on the P2.10 / EINT0 / NMI pin.
00042     3 - Start conversion when the edge selected by bit 27 occurs on the P1.27 / CLKOUT /
00043         USB_OVRCRn / CAP0.1 pin.
00044     4 - Start conversion when the edge selected by bit 27 occurs on MAT0.1. Note that this does
00045         not require that the MAT0.1 function appear on a device pin.
00046     5 - Start conversion when the edge selected by bit 27 occurs on MAT0.3. Note that it is not
00047         possible to cause the MAT0.3 function to appear on a device pin.
00048     6 - Start conversion when the edge selected by bit 27 occurs on MAT1.0. Note that this does
00049         not require that the MAT1.0 function appear on a device pin.
00050     7 - Start conversion when the edge selected by bit 27 occurs on MAT1.1. Note that this does
00051         not require that the MAT1.1 function appear on a device pin.
00052     When mode >= 2, conversion is triggered by edge:
00053     0 - Rising edge
00054     1 - Falling edge
00055     */
00056     void startmode(int mode, int edge);
00057     
00058     //Return startmode state according to mode_edge=0: mode and mode_edge=1: edge
00059     int startmode(int mode_edge);
00060     
00061     //Start ADC conversion
00062     void start(void);
00063 
00064     //Set interrupt enable/disable for pin to state
00065     void interrupt_state(PinName pin, int state);
00066     
00067     //Return enable/disable state of interrupt for pin
00068     int interrupt_state(PinName pin);
00069 
00070     //Attach custom interrupt handler replacing default
00071     void attach(void(*fptr)(void));
00072 
00073     //Restore default interrupt handler
00074     void detach(void);
00075 
00076     //Append custom interrupt handler for pin
00077     void append(PinName pin, void(*fptr)(uint32_t value));
00078 
00079     //Unappend custom interrupt handler for pin
00080     void unappend(PinName pin);
00081 
00082     //Append custom global interrupt handler
00083     void append(void(*fptr)(int chan, uint32_t value));
00084 
00085     //Unappend custom global interrupt handler
00086     void unappend(void);
00087 
00088     //Set ADC offset to a value 0-7
00089     void offset(int offset);
00090     
00091     //Return current ADC offset
00092     int offset(void);
00093 
00094     //Return value of ADC on pin
00095     int read(PinName pin);
00096 
00097     //Return DONE flag of ADC on pin
00098     int done(PinName pin);
00099     
00100     //Return OVERRUN flag of ADC on pin
00101     int overrun(PinName pin);
00102 
00103     //Return actual ADC clock
00104     int actual_adc_clock(void);
00105     
00106     //Return actual maximum sample rate
00107     int actual_sample_rate(void);
00108 
00109     //Return pin ID of ADC channel
00110     PinName channel_to_pin(int chan);
00111 
00112     //Return pin number of ADC channel
00113     int channel_to_pin_number(int chan);
00114 
00115 
00116 private:
00117     int _pin_to_channel(PinName pin);
00118     uint32_t _data_of_pin(PinName pin);
00119 
00120     int _adc_clk_freq;
00121     void adcisr(void);
00122     static void _adcisr(void);
00123     static ADC *instance;
00124     
00125     uint32_t _adc_data[8];
00126     void(*_adc_isr[8])(uint32_t value);
00127     void(*_adc_g_isr)(int chan, uint32_t value);
00128     void(*_adc_m_isr)(void);
00129 };
00130 
00131 #endif