Mike R / FastAnalogIn

Class similar to AnalogIn that uses burst mode to run continious background conversions so when the input is read, the last value can immediatly be returned. This slightly modified version allows NC pins.

Dependents:   Pinscape_Controller

Fork of FastAnalogIn by Erik -

FastAnalogIn.h@0:c2a7b899e6c7, 2013-05-09 (annotated)

Committer:
Sissors
Date:
Thu May 09 17:46:32 2013 +0000
Revision:
0:c2a7b899e6c7
Child:
2:9b61d0792927
v0.1

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Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 0:c2a7b899e6c7 1 #ifndef FASTANALOGIN_H
Sissors 0:c2a7b899e6c7 2 #define FASTANALOGIN_H
Sissors 0:c2a7b899e6c7 3
Sissors 0:c2a7b899e6c7 4 /*
Sissors 0:c2a7b899e6c7 5 * Includes
Sissors 0:c2a7b899e6c7 6 */
Sissors 0:c2a7b899e6c7 7 #include "mbed.h"
Sissors 0:c2a7b899e6c7 8 #include "pinmap.h"
Sissors 0:c2a7b899e6c7 9
Sissors 0:c2a7b899e6c7 10 #ifndef TARGET_LPC1768
Sissors 0:c2a7b899e6c7 11 #error "Target not supported"
Sissors 0:c2a7b899e6c7 12 #endif
Sissors 0:c2a7b899e6c7 13
Sissors 0:c2a7b899e6c7 14 /** A class that is similar to AnalogIn, only faster
Sissors 0:c2a7b899e6c7 15 *
Sissors 0:c2a7b899e6c7 16 * AnalogIn does a single conversion when you read a value (actually several conversions and it takes the median of that).
Sissors 0:c2a7b899e6c7 17 * This library has all used ADC channels running automatically in the background, and if you read a value it will immediatly return the last converted value.
Sissors 0:c2a7b899e6c7 18 *
Sissors 0:c2a7b899e6c7 19 * You can use several FastAnalogIn objects per ADC pin, and several ADC pins at the same time. Using more ADC pins will decrease the conversion rate.
Sissors 0:c2a7b899e6c7 20 * If you need to generally convert one pin very fast, but sometimes also need to do AD conversions on another pin, you can disable the ADC channel and still read its value.
Sissors 0:c2a7b899e6c7 21 * Only now it will block until conversion is complete, so more like the regular AnalogIn library. Of course you can also disable an ADC channel and enable it later.
Sissors 0:c2a7b899e6c7 22 *
Sissors 0:c2a7b899e6c7 23 * It does not play nicely with regular AnalogIn objects, so use only this library or only AnalogIn. Also currently only LPC1768 is supported.
Sissors 0:c2a7b899e6c7 24 */
Sissors 0:c2a7b899e6c7 25 class FastAnalogIn {
Sissors 0:c2a7b899e6c7 26
Sissors 0:c2a7b899e6c7 27 public:
Sissors 0:c2a7b899e6c7 28 /** Create a FastAnalogIn, connected to the specified pin
Sissors 0:c2a7b899e6c7 29 *
Sissors 0:c2a7b899e6c7 30 * @param pin AnalogIn pin to connect to
Sissors 0:c2a7b899e6c7 31 * @param enabled Enable the ADC channel (default = true)
Sissors 0:c2a7b899e6c7 32 */
Sissors 0:c2a7b899e6c7 33 FastAnalogIn( PinName pin, bool enabled = true );
Sissors 0:c2a7b899e6c7 34
Sissors 0:c2a7b899e6c7 35 ~FastAnalogIn( void );
Sissors 0:c2a7b899e6c7 36
Sissors 0:c2a7b899e6c7 37 /** Enable the ADC channel
Sissors 0:c2a7b899e6c7 38 *
Sissors 0:c2a7b899e6c7 39 * @param enabled Bool that is true for enable, false is equivalent to calling disable
Sissors 0:c2a7b899e6c7 40 */
Sissors 0:c2a7b899e6c7 41 void enable(bool enabled = true);
Sissors 0:c2a7b899e6c7 42
Sissors 0:c2a7b899e6c7 43 /** Disable the ADC channel
Sissors 0:c2a7b899e6c7 44 *
Sissors 0:c2a7b899e6c7 45 * Disabling unused channels speeds up conversion in used channels.
Sissors 0:c2a7b899e6c7 46 * When disabled you can still call read, that will do a single conversion (actually two since the first one always returns 0 for unknown reason).
Sissors 0:c2a7b899e6c7 47 * Then the function blocks until the value is read. This is handy when you sometimes needs a single conversion besides the automatic conversion
Sissors 0:c2a7b899e6c7 48 */
Sissors 0:c2a7b899e6c7 49 void disable( void );
Sissors 0:c2a7b899e6c7 50
Sissors 0:c2a7b899e6c7 51 /** Returns the raw value
Sissors 0:c2a7b899e6c7 52 *
Sissors 0:c2a7b899e6c7 53 * @param return Unsigned integer with converted value
Sissors 0:c2a7b899e6c7 54 */
Sissors 0:c2a7b899e6c7 55 unsigned short read_u16( void );
Sissors 0:c2a7b899e6c7 56
Sissors 0:c2a7b899e6c7 57 /** Returns the scaled value
Sissors 0:c2a7b899e6c7 58 *
Sissors 0:c2a7b899e6c7 59 * @param return Float with scaled converted value to 0.0-1.0
Sissors 0:c2a7b899e6c7 60 */
Sissors 0:c2a7b899e6c7 61 float read( void );
Sissors 0:c2a7b899e6c7 62
Sissors 0:c2a7b899e6c7 63 /** An operator shorthand for read()
Sissors 0:c2a7b899e6c7 64 */
Sissors 0:c2a7b899e6c7 65 operator float() {
Sissors 0:c2a7b899e6c7 66 return read();
Sissors 0:c2a7b899e6c7 67 }
Sissors 0:c2a7b899e6c7 68
Sissors 0:c2a7b899e6c7 69
Sissors 0:c2a7b899e6c7 70 private:
Sissors 0:c2a7b899e6c7 71 static const PinMap PinMap_ADC[9];
Sissors 0:c2a7b899e6c7 72 static int channel_usage[8];
Sissors 0:c2a7b899e6c7 73
Sissors 0:c2a7b899e6c7 74 bool running;
Sissors 0:c2a7b899e6c7 75 char ADCnumber;
Sissors 0:c2a7b899e6c7 76 uint32_t *datareg;
Sissors 0:c2a7b899e6c7 77
Sissors 0:c2a7b899e6c7 78
Sissors 0:c2a7b899e6c7 79
Sissors 0:c2a7b899e6c7 80
Sissors 0:c2a7b899e6c7 81 };
Sissors 0:c2a7b899e6c7 82
Sissors 0:c2a7b899e6c7 83 #endif