Ernesto Palacios / FastAnalogIn

FastAnalogIn

Fork of FastAnalogIn by Erik -

FastAnalogIn.h@2:9b61d0792927, 2014-03-08 (annotated)

Committer:
frankvnk
Date:
Sat Mar 08 15:44:57 2014 +0000
Revision:
2:9b61d0792927
Parent:
0:c2a7b899e6c7
Child:
3:a9b753c25073
Added KLxx support

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
frankvnk 2:9b61d0792927 10 #if !defined TARGET_LPC1768 && !defined TARGET_KL25Z && !defined TARGET_KL46Z && !defined TARGET_KL05Z
Sissors 0:c2a7b899e6c7 11 #error "Target not supported"
Sissors 0:c2a7b899e6c7 12 #endif
Sissors 0:c2a7b899e6c7 13
frankvnk 2:9b61d0792927 14 /** A class similar to AnalogIn, only faster, for LPC1768 and KLxx
frankvnk 2:9b61d0792927 15 *
frankvnk 2:9b61d0792927 16 * AnalogIn does a single conversion when you read a value (actually several conversions and it takes the median of that).
frankvnk 2:9b61d0792927 17 * This library runns the ADC conversion automatically in the background.
frankvnk 2:9b61d0792927 18 * When read is called, it immediatly returns the last sampled value.
frankvnk 2:9b61d0792927 19 * Using more ADC pins in continuous mode will decrease the conversion rate.
frankvnk 2:9b61d0792927 20 * If you need to sample one pin very fast and sometimes also need to do AD conversions on another pin,
frankvnk 2:9b61d0792927 21 * you can disable the continuous conversion on that ADC channel and still read its value.
frankvnk 2:9b61d0792927 22 * When continuous conversion is disabled, a read will block until the conversion is complete (much like the regular AnalogIn library does).
frankvnk 2:9b61d0792927 23 * Each ADC channel can be enabled/disabled separately.
frankvnk 2:9b61d0792927 24 *
frankvnk 2:9b61d0792927 25 * IMPORTANT NOTES
frankvnk 2:9b61d0792927 26 * ---------------
frankvnk 2:9b61d0792927 27 * - When used with KLxx processors, this library can coexist with the regular AnalogIn library.
frankvnk 2:9b61d0792927 28 * - When used with the LPC1768 processor, it does not play nicely with regular AnalogIn objects,
frankvnk 2:9b61d0792927 29 * so either use this library or AnalogIn, not both at the same time!!
frankvnk 2:9b61d0792927 30 *
frankvnk 2:9b61d0792927 31 * Example for the KLxx processors:
frankvnk 2:9b61d0792927 32 * @code
frankvnk 2:9b61d0792927 33 * // Print messages when the AnalogIn is greater than 50%
frankvnk 2:9b61d0792927 34 *
frankvnk 2:9b61d0792927 35 * #include "mbed.h"
frankvnk 2:9b61d0792927 36 *
frankvnk 2:9b61d0792927 37 * FastAnalogIn temperature(PTC2); //Fast sampling on PTC2
frankvnk 2:9b61d0792927 38 * AnalogIn speed(PTB3); //Normal sampling on PTB3
frankvnk 2:9b61d0792927 39 *
frankvnk 2:9b61d0792927 40 * int main() {
frankvnk 2:9b61d0792927 41 * while(1) {
frankvnk 2:9b61d0792927 42 * if(temperature > 0.5) {
frankvnk 2:9b61d0792927 43 * printf("Too hot! (%f) at speed %f", temperature.read(), speed.read());
frankvnk 2:9b61d0792927 44 * }
frankvnk 2:9b61d0792927 45 * }
frankvnk 2:9b61d0792927 46 * }
frankvnk 2:9b61d0792927 47 * @endcode
frankvnk 2:9b61d0792927 48 * Example for the LPC1768 processor:
frankvnk 2:9b61d0792927 49 * @code
frankvnk 2:9b61d0792927 50 * // Print messages when the AnalogIn is greater than 50%
frankvnk 2:9b61d0792927 51 *
frankvnk 2:9b61d0792927 52 * #include "mbed.h"
frankvnk 2:9b61d0792927 53 *
frankvnk 2:9b61d0792927 54 * AnalogIn temperature(p20);
frankvnk 2:9b61d0792927 55 *
frankvnk 2:9b61d0792927 56 * int main() {
frankvnk 2:9b61d0792927 57 * while(1) {
frankvnk 2:9b61d0792927 58 * if(temperature > 0.5) {
frankvnk 2:9b61d0792927 59 * printf("Too hot! (%f)", temperature.read());
frankvnk 2:9b61d0792927 60 * }
frankvnk 2:9b61d0792927 61 * }
frankvnk 2:9b61d0792927 62 * }
frankvnk 2:9b61d0792927 63 * @endcode
Sissors 0:c2a7b899e6c7 64 */
Sissors 0:c2a7b899e6c7 65 class FastAnalogIn {
Sissors 0:c2a7b899e6c7 66
Sissors 0:c2a7b899e6c7 67 public:
Sissors 0:c2a7b899e6c7 68 /** Create a FastAnalogIn, connected to the specified pin
Sissors 0:c2a7b899e6c7 69 *
Sissors 0:c2a7b899e6c7 70 * @param pin AnalogIn pin to connect to
Sissors 0:c2a7b899e6c7 71 * @param enabled Enable the ADC channel (default = true)
Sissors 0:c2a7b899e6c7 72 */
Sissors 0:c2a7b899e6c7 73 FastAnalogIn( PinName pin, bool enabled = true );
Sissors 0:c2a7b899e6c7 74
frankvnk 2:9b61d0792927 75 ~FastAnalogIn( void )
frankvnk 2:9b61d0792927 76 {
frankvnk 2:9b61d0792927 77 disable();
frankvnk 2:9b61d0792927 78 }
Sissors 0:c2a7b899e6c7 79
Sissors 0:c2a7b899e6c7 80 /** Enable the ADC channel
Sissors 0:c2a7b899e6c7 81 *
Sissors 0:c2a7b899e6c7 82 * @param enabled Bool that is true for enable, false is equivalent to calling disable
Sissors 0:c2a7b899e6c7 83 */
Sissors 0:c2a7b899e6c7 84 void enable(bool enabled = true);
Sissors 0:c2a7b899e6c7 85
Sissors 0:c2a7b899e6c7 86 /** Disable the ADC channel
Sissors 0:c2a7b899e6c7 87 *
Sissors 0:c2a7b899e6c7 88 * Disabling unused channels speeds up conversion in used channels.
Sissors 0:c2a7b899e6c7 89 * 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 90 * 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 91 */
Sissors 0:c2a7b899e6c7 92 void disable( void );
Sissors 0:c2a7b899e6c7 93
Sissors 0:c2a7b899e6c7 94 /** Returns the raw value
Sissors 0:c2a7b899e6c7 95 *
Sissors 0:c2a7b899e6c7 96 * @param return Unsigned integer with converted value
Sissors 0:c2a7b899e6c7 97 */
Sissors 0:c2a7b899e6c7 98 unsigned short read_u16( void );
Sissors 0:c2a7b899e6c7 99
Sissors 0:c2a7b899e6c7 100 /** Returns the scaled value
Sissors 0:c2a7b899e6c7 101 *
Sissors 0:c2a7b899e6c7 102 * @param return Float with scaled converted value to 0.0-1.0
Sissors 0:c2a7b899e6c7 103 */
frankvnk 2:9b61d0792927 104 float read( void )
frankvnk 2:9b61d0792927 105 {
frankvnk 2:9b61d0792927 106 unsigned short value = read_u16();
frankvnk 2:9b61d0792927 107 return (float)value/65535;
frankvnk 2:9b61d0792927 108 }
Sissors 0:c2a7b899e6c7 109
Sissors 0:c2a7b899e6c7 110 /** An operator shorthand for read()
Sissors 0:c2a7b899e6c7 111 */
Sissors 0:c2a7b899e6c7 112 operator float() {
Sissors 0:c2a7b899e6c7 113 return read();
Sissors 0:c2a7b899e6c7 114 }
Sissors 0:c2a7b899e6c7 115
Sissors 0:c2a7b899e6c7 116
Sissors 0:c2a7b899e6c7 117 private:
Sissors 0:c2a7b899e6c7 118 static int channel_usage[8];
Sissors 0:c2a7b899e6c7 119 bool running;
Sissors 0:c2a7b899e6c7 120 char ADCnumber;
Sissors 0:c2a7b899e6c7 121 uint32_t *datareg;
Sissors 0:c2a7b899e6c7 122 };
Sissors 0:c2a7b899e6c7 123
frankvnk 2:9b61d0792927 124 #endif