Gurhan ANIK / FastPWM

changed for STM32F4

Fork of FastPWM by Erik -

FastPWM.h@3:3094d3806cfc, 2012-07-25 (annotated)

Committer:
Sissors
Date:
Wed Jul 25 07:14:39 2012 +0000
Revision:
3:3094d3806cfc
Parent:
1:1aed61747ed6
Child:
4:a7b9f778c4b4
Fixed clk_sel, latch registers and constant duty when changing period

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 1:1aed61747ed6 1 /*
Sissors 1:1aed61747ed6 2 .---. _....._
Sissors 1:1aed61747ed6 3 / p `\ .-""`: :`"-.
Sissors 1:1aed61747ed6 4 |__ - | ,' . ' ',
Sissors 1:1aed61747ed6 5 ._> \ /: : ; :,
Sissors 1:1aed61747ed6 6 '-. '\`. . : ' \
Sissors 1:1aed61747ed6 7 `. | .'._.' '._.' '._.'. |
Sissors 1:1aed61747ed6 8 `;-\. : : ' '/,__,
Sissors 1:1aed61747ed6 9 .-'`'._ ' . : _.'.__.'
Sissors 1:1aed61747ed6 10 ((((-'/ `";--..:..--;"` \
Sissors 1:1aed61747ed6 11 .' / \ \
Sissors 1:1aed61747ed6 12 jgs ((((-' ((((-'
Sissors 1:1aed61747ed6 13
Sissors 1:1aed61747ed6 14 Yeah ASCII art turtle more fun than copyright stuff
Sissors 1:1aed61747ed6 15 */
Sissors 1:1aed61747ed6 16
Sissors 1:1aed61747ed6 17
Sissors 0:f8c1b0ad5371 18 #include "mbed.h"
Sissors 0:f8c1b0ad5371 19
Sissors 0:f8c1b0ad5371 20
Sissors 0:f8c1b0ad5371 21 #ifndef FASTPWM_H
Sissors 0:f8c1b0ad5371 22 #define FASTPWM_H
Sissors 0:f8c1b0ad5371 23
Sissors 0:f8c1b0ad5371 24 #ifndef F_CLK
Sissors 0:f8c1b0ad5371 25 #define F_CLK 96000000
Sissors 0:f8c1b0ad5371 26 #endif
Sissors 0:f8c1b0ad5371 27
Sissors 0:f8c1b0ad5371 28 /** Library that allows faster and/or higher resolution PWM output
Sissors 0:f8c1b0ad5371 29 *
Sissors 0:f8c1b0ad5371 30 * Library can directly replace standard mbed PWM library. Only limitation is that the maximum PWM period is four times shorter
Sissors 0:f8c1b0ad5371 31 * The maximum achievable period is roughly 40 seconds, I dont think that should be a problem.
Sissors 0:f8c1b0ad5371 32 * Do take into account all PWM objects will run four times faster than default.
Sissors 0:f8c1b0ad5371 33 *
Sissors 0:f8c1b0ad5371 34 * Contrary to the default mbed library, this library takes doubles instead of floats. The compiler will autocast if needed,
Sissors 0:f8c1b0ad5371 35 * but do take into account it is done for a reason, your accuracy will otherwise be limitted by the floating point precision.
Sissors 0:f8c1b0ad5371 36 *
Sissors 0:f8c1b0ad5371 37 * In your program you can define F_CLK if you use a different clock frequency than the default one.
Sissors 0:f8c1b0ad5371 38 *
Sissors 0:f8c1b0ad5371 39 * Only works on LPC1768 for now. If you want support for the other one, send a PM and I will have a look, but I cannot even compile for it.
Sissors 0:f8c1b0ad5371 40 */
Sissors 0:f8c1b0ad5371 41 class FastPWM {
Sissors 0:f8c1b0ad5371 42 public:
Sissors 0:f8c1b0ad5371 43 /**
Sissors 0:f8c1b0ad5371 44 * Create a FastPWM object connected to the specified pin
Sissors 0:f8c1b0ad5371 45 *
Sissors 0:f8c1b0ad5371 46 * @param pin - PWM pin to connect to
Sissors 0:f8c1b0ad5371 47 */
Sissors 0:f8c1b0ad5371 48 FastPWM(PinName pin);
Sissors 0:f8c1b0ad5371 49
Sissors 0:f8c1b0ad5371 50 /**
Sissors 0:f8c1b0ad5371 51 * Set the PWM period, specified in seconds (double), keeping the duty cycle the same.
Sissors 0:f8c1b0ad5371 52 */
Sissors 0:f8c1b0ad5371 53 void period(double seconds);
Sissors 0:f8c1b0ad5371 54
Sissors 0:f8c1b0ad5371 55 /**
Sissors 0:f8c1b0ad5371 56 * Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
Sissors 0:f8c1b0ad5371 57 */
Sissors 0:f8c1b0ad5371 58 void period_ms(int ms);
Sissors 0:f8c1b0ad5371 59
Sissors 0:f8c1b0ad5371 60 /**
Sissors 0:f8c1b0ad5371 61 * Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
Sissors 0:f8c1b0ad5371 62 */
Sissors 0:f8c1b0ad5371 63 void period_us(int us);
Sissors 0:f8c1b0ad5371 64
Sissors 0:f8c1b0ad5371 65 /**
Sissors 0:f8c1b0ad5371 66 * Set the PWM period, specified in micro-seconds (double), keeping the duty cycle the same.
Sissors 0:f8c1b0ad5371 67 */
Sissors 0:f8c1b0ad5371 68 void period_us(double us);
Sissors 0:f8c1b0ad5371 69
Sissors 0:f8c1b0ad5371 70 /**
Sissors 0:f8c1b0ad5371 71 * Set the PWM pulsewidth, specified in seconds (double), keeping the period the same.
Sissors 0:f8c1b0ad5371 72 */
Sissors 0:f8c1b0ad5371 73 void pulsewidth(double seconds);
Sissors 0:f8c1b0ad5371 74
Sissors 0:f8c1b0ad5371 75 /**
Sissors 0:f8c1b0ad5371 76 * Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
Sissors 0:f8c1b0ad5371 77 */
Sissors 0:f8c1b0ad5371 78 void pulsewidth_ms(int ms);
Sissors 0:f8c1b0ad5371 79
Sissors 0:f8c1b0ad5371 80 /**
Sissors 0:f8c1b0ad5371 81 * Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
Sissors 0:f8c1b0ad5371 82 */
Sissors 0:f8c1b0ad5371 83 void pulsewidth_us(int us);
Sissors 0:f8c1b0ad5371 84
Sissors 0:f8c1b0ad5371 85 /**
Sissors 0:f8c1b0ad5371 86 * Set the PWM pulsewidth, specified in micro-seconds (double), keeping the period the same.
Sissors 0:f8c1b0ad5371 87 */
Sissors 0:f8c1b0ad5371 88 void pulsewidth_us(double us);
Sissors 0:f8c1b0ad5371 89
Sissors 0:f8c1b0ad5371 90 /**
Sissors 0:f8c1b0ad5371 91 * Set the ouput duty-cycle, specified as a percentage (double)
Sissors 0:f8c1b0ad5371 92 *
Sissors 0:f8c1b0ad5371 93 * @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%).
Sissors 0:f8c1b0ad5371 94 */
Sissors 0:f8c1b0ad5371 95 void write(double duty);
Sissors 0:f8c1b0ad5371 96
Sissors 0:f8c1b0ad5371 97 /**
Sissors 0:f8c1b0ad5371 98 * Return the ouput duty-cycle, specified as a percentage (double)
Sissors 0:f8c1b0ad5371 99 *
Sissors 0:f8c1b0ad5371 100 * @param return - A double value representing the output duty-cycle, specified as a percentage.
Sissors 0:f8c1b0ad5371 101 */
Sissors 0:f8c1b0ad5371 102 double read( void );
Sissors 0:f8c1b0ad5371 103
Sissors 0:f8c1b0ad5371 104 /**
Sissors 0:f8c1b0ad5371 105 * An operator shorthand for write()
Sissors 0:f8c1b0ad5371 106 */
Sissors 0:f8c1b0ad5371 107 FastPWM& operator= (double value);
Sissors 0:f8c1b0ad5371 108
Sissors 0:f8c1b0ad5371 109 /**
Sissors 0:f8c1b0ad5371 110 * An operator shorthand for read()
Sissors 0:f8c1b0ad5371 111 */
Sissors 0:f8c1b0ad5371 112 operator double();
Sissors 0:f8c1b0ad5371 113
Sissors 0:f8c1b0ad5371 114 private:
Sissors 0:f8c1b0ad5371 115 PwmOut PWMObject;
Sissors 0:f8c1b0ad5371 116 double _duty;
Sissors 0:f8c1b0ad5371 117 double _period;
Sissors 3:3094d3806cfc 118 unsigned int PWMUnit;
Sissors 0:f8c1b0ad5371 119
Sissors 0:f8c1b0ad5371 120 __IO uint32_t *MR;
Sissors 0:f8c1b0ad5371 121
Sissors 0:f8c1b0ad5371 122 };
Sissors 0:f8c1b0ad5371 123 #endif