V D / Mbed 2 deprecated di19sept2017

Potmeter FastPWM.h

Dependencies:   mbed

FastPWM.h@0:16be67f4d9ac, 2017-09-19 (annotated)

Committer:
vd
Date:
Tue Sep 19 16:52:01 2017 +0000
Revision:
0:16be67f4d9ac
Potmeter FastPWM.h

Who changed what in which revision?

UserRevisionLine numberNew contents of line
vd 0:16be67f4d9ac 1 /*
vd 0:16be67f4d9ac 2 .---. _....._
vd 0:16be67f4d9ac 3 / p `\ .-""`: :`"-.
vd 0:16be67f4d9ac 4 |__ - | ,' . ' ',
vd 0:16be67f4d9ac 5 ._> \ /: : ; :,
vd 0:16be67f4d9ac 6 '-. '\`. . : ' \
vd 0:16be67f4d9ac 7 `. | .'._.' '._.' '._.'. |
vd 0:16be67f4d9ac 8 `;-\. : : ' '/,__,
vd 0:16be67f4d9ac 9 .-'`'._ ' . : _.'.__.'
vd 0:16be67f4d9ac 10 ((((-'/ `";--..:..--;"` \
vd 0:16be67f4d9ac 11 .' / \ \
vd 0:16be67f4d9ac 12 jgs ((((-' ((((-'
vd 0:16be67f4d9ac 13
vd 0:16be67f4d9ac 14 Yeah ASCII art turtle more fun than copyright stuff
vd 0:16be67f4d9ac 15 */
vd 0:16be67f4d9ac 16
vd 0:16be67f4d9ac 17
vd 0:16be67f4d9ac 18 #include "mbed.h"
vd 0:16be67f4d9ac 19
vd 0:16be67f4d9ac 20 #ifndef FASTPWM_H
vd 0:16be67f4d9ac 21 #define FASTPWM_H
vd 0:16be67f4d9ac 22
vd 0:16be67f4d9ac 23 /** Library that allows faster and/or higher resolution PWM output
vd 0:16be67f4d9ac 24 *
vd 0:16be67f4d9ac 25 * Library can directly replace standard mbed PWM library.
vd 0:16be67f4d9ac 26 *
vd 0:16be67f4d9ac 27 * Contrary to the default mbed library, this library takes doubles instead of floats. The compiler will autocast if needed,
vd 0:16be67f4d9ac 28 * but do take into account it is done for a reason, your accuracy will otherwise be limitted by the floating point precision.
vd 0:16be67f4d9ac 29 */
vd 0:16be67f4d9ac 30 class FastPWM : public PwmOut {
vd 0:16be67f4d9ac 31 public:
vd 0:16be67f4d9ac 32 /**
vd 0:16be67f4d9ac 33 * Create a FastPWM object connected to the specified pin
vd 0:16be67f4d9ac 34 *
vd 0:16be67f4d9ac 35 * @param pin - PWM pin to connect to
vd 0:16be67f4d9ac 36 * @param prescaler - Clock prescaler, -1 is dynamic (default), 0 is bit random, everything else normal
vd 0:16be67f4d9ac 37 */
vd 0:16be67f4d9ac 38 FastPWM(PinName pin, int prescaler = -1);
vd 0:16be67f4d9ac 39 ~FastPWM();
vd 0:16be67f4d9ac 40
vd 0:16be67f4d9ac 41 /**
vd 0:16be67f4d9ac 42 * Set the PWM period, specified in seconds (double), keeping the pulsewidth the same.
vd 0:16be67f4d9ac 43 */
vd 0:16be67f4d9ac 44 void period(double seconds);
vd 0:16be67f4d9ac 45
vd 0:16be67f4d9ac 46 /**
vd 0:16be67f4d9ac 47 * Set the PWM period, specified in milli-seconds (int), keeping the pulsewidth the same.
vd 0:16be67f4d9ac 48 */
vd 0:16be67f4d9ac 49 void period_ms(int ms);
vd 0:16be67f4d9ac 50
vd 0:16be67f4d9ac 51 /**
vd 0:16be67f4d9ac 52 * Set the PWM period, specified in micro-seconds (int), keeping the pulsewidth the same.
vd 0:16be67f4d9ac 53 */
vd 0:16be67f4d9ac 54 void period_us(int us);
vd 0:16be67f4d9ac 55
vd 0:16be67f4d9ac 56 /**
vd 0:16be67f4d9ac 57 * Set the PWM period, specified in micro-seconds (double), keeping the pulsewidth the same.
vd 0:16be67f4d9ac 58 */
vd 0:16be67f4d9ac 59 void period_us(double us);
vd 0:16be67f4d9ac 60
vd 0:16be67f4d9ac 61 /**
vd 0:16be67f4d9ac 62 * Set the PWM period, specified in clock ticks, keeping _pulse width_ the same.
vd 0:16be67f4d9ac 63 *
vd 0:16be67f4d9ac 64 * This function can be used if low overhead is required. Do take into account the result is
vd 0:16be67f4d9ac 65 * board (clock frequency) dependent, and this does not keep an equal duty cycle!
vd 0:16be67f4d9ac 66 */
vd 0:16be67f4d9ac 67 void period_ticks(uint32_t ticks);
vd 0:16be67f4d9ac 68
vd 0:16be67f4d9ac 69 /**
vd 0:16be67f4d9ac 70 * Set the PWM pulsewidth, specified in seconds (double), keeping the period the same.
vd 0:16be67f4d9ac 71 */
vd 0:16be67f4d9ac 72 void pulsewidth(double seconds);
vd 0:16be67f4d9ac 73
vd 0:16be67f4d9ac 74 /**
vd 0:16be67f4d9ac 75 * Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
vd 0:16be67f4d9ac 76 */
vd 0:16be67f4d9ac 77 void pulsewidth_ms(int ms);
vd 0:16be67f4d9ac 78
vd 0:16be67f4d9ac 79 /**
vd 0:16be67f4d9ac 80 * Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
vd 0:16be67f4d9ac 81 */
vd 0:16be67f4d9ac 82 void pulsewidth_us(int us);
vd 0:16be67f4d9ac 83
vd 0:16be67f4d9ac 84 /**
vd 0:16be67f4d9ac 85 * Set the PWM pulsewidth, specified in micro-seconds (double), keeping the period the same.
vd 0:16be67f4d9ac 86 */
vd 0:16be67f4d9ac 87 void pulsewidth_us(double us);
vd 0:16be67f4d9ac 88
vd 0:16be67f4d9ac 89 /**
vd 0:16be67f4d9ac 90 * Set the PWM period, specified in clock ticks, keeping the period the same.
vd 0:16be67f4d9ac 91 *
vd 0:16be67f4d9ac 92 * This function can be used if low overhead is required. Do take into account the result is
vd 0:16be67f4d9ac 93 * board (clock frequency) dependent!
vd 0:16be67f4d9ac 94 */
vd 0:16be67f4d9ac 95 void pulsewidth_ticks(uint32_t ticks);
vd 0:16be67f4d9ac 96
vd 0:16be67f4d9ac 97 /**
vd 0:16be67f4d9ac 98 * Set the ouput duty-cycle, specified as a percentage (double)
vd 0:16be67f4d9ac 99 *
vd 0:16be67f4d9ac 100 * @param duty - A double value representing the output duty-cycle, specified as a percentage. The value should lie between 0.0 (representing on 0%) and 1.0 (representing on 100%).
vd 0:16be67f4d9ac 101 */
vd 0:16be67f4d9ac 102 void write(double duty);
vd 0:16be67f4d9ac 103
vd 0:16be67f4d9ac 104 /**
vd 0:16be67f4d9ac 105 * Return the ouput duty-cycle, specified as a percentage (double)
vd 0:16be67f4d9ac 106 *
vd 0:16be67f4d9ac 107 * @param return - A double value representing the output duty-cycle, specified as a percentage.
vd 0:16be67f4d9ac 108 */
vd 0:16be67f4d9ac 109 double read( void );
vd 0:16be67f4d9ac 110
vd 0:16be67f4d9ac 111 /**
vd 0:16be67f4d9ac 112 * An operator shorthand for write()
vd 0:16be67f4d9ac 113 */
vd 0:16be67f4d9ac 114 FastPWM& operator= (double value);
vd 0:16be67f4d9ac 115
vd 0:16be67f4d9ac 116 /**
vd 0:16be67f4d9ac 117 * An operator shorthand for read()
vd 0:16be67f4d9ac 118 */
vd 0:16be67f4d9ac 119 operator double();
vd 0:16be67f4d9ac 120
vd 0:16be67f4d9ac 121 /**
vd 0:16be67f4d9ac 122 * Set the PWM prescaler
vd 0:16be67f4d9ac 123 *
vd 0:16be67f4d9ac 124 * The period of all PWM pins on the same PWM unit have to be reset after using this!
vd 0:16be67f4d9ac 125 *
vd 0:16be67f4d9ac 126 * @param value - The required prescaler. Special values: 0 = lock current prescaler, -1 = use dynamic prescaler
vd 0:16be67f4d9ac 127 * @param return - The prescaler which was set (can differ from requested prescaler if not possible)
vd 0:16be67f4d9ac 128 */
vd 0:16be67f4d9ac 129 int prescaler(int value);
vd 0:16be67f4d9ac 130
vd 0:16be67f4d9ac 131 private:
vd 0:16be67f4d9ac 132 void initFastPWM(void);
vd 0:16be67f4d9ac 133
vd 0:16be67f4d9ac 134 uint32_t setPrescaler( uint32_t reqScale );
vd 0:16be67f4d9ac 135 int calcPrescaler(uint64_t clocks);
vd 0:16be67f4d9ac 136 uint32_t getPeriod( void );
vd 0:16be67f4d9ac 137
vd 0:16be67f4d9ac 138 void updateTicks( uint32_t prescaler );
vd 0:16be67f4d9ac 139 uint32_t bits;
vd 0:16be67f4d9ac 140
vd 0:16be67f4d9ac 141 double _duty;
vd 0:16be67f4d9ac 142
vd 0:16be67f4d9ac 143 double dticks, dticks_us;
vd 0:16be67f4d9ac 144 int iticks_ms, iticks_us;
vd 0:16be67f4d9ac 145
vd 0:16be67f4d9ac 146 bool dynamicPrescaler;
vd 0:16be67f4d9ac 147
vd 0:16be67f4d9ac 148 void *fast_obj;
vd 0:16be67f4d9ac 149 };
vd 0:16be67f4d9ac 150 #endif