Revision 4:923b54e7c2c1, committed 2013-05-23

Comitter:

jocis

Date:

Thu May 23 10:39:29 2013 +0000

Parent:

3:3094d3806cfc

Commit message:

based on FastPWM, changed double calculation to int calculation for most functions

Changed in this revision

diff -r 3094d3806cfc -r 923b54e7c2c1 FastPWM.cpp
--- a/FastPWM.cpp	Wed Jul 25 07:14:39 2012 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,93 +0,0 @@
-#include "FastPWM.h"
-
-FastPWM::FastPWM(PinName pin) : PWMObject(pin){
-    //Set clock source
-    LPC_SC->PCLKSEL0|=1<<12;
-    
-    _duty=0;
-    _period=0.02;
-    if (pin==p26||pin==LED1) {
-        PWMUnit=1;
-        MR=&LPC_PWM1->MR1;
-        }
-    else if (pin==p25||pin==LED2){
-        PWMUnit=2;
-        MR=&LPC_PWM1->MR2;
-        }
-    else if (pin==p24||pin==LED3){
-        PWMUnit=3;
-        MR=&LPC_PWM1->MR3;
-        }
-    else if (pin==p23||pin==LED4){
-        PWMUnit=4;
-        MR=&LPC_PWM1->MR4;
-        }
-    else if (pin==p22){
-        PWMUnit=5;
-        MR=&LPC_PWM1->MR5;
-        }
-    else if (pin==p21){
-        PWMUnit=6;
-        MR=&LPC_PWM1->MR6;
-        }
-    else
-        error("No hardware PWM pin\n\r");
-    
-    period(_period);
-}
-
-void FastPWM::period(double seconds) {
-    LPC_PWM1->MR0 = (unsigned int) (seconds * (double)F_CLK);
-    LPC_PWM1->LER |= 1;
-    _period = seconds;
-    pulsewidth(_duty*_period);
-}
-
-void FastPWM::period_ms(int ms) {
-    period((double)ms/1000.0);
-}
-
-void FastPWM::period_us(int us) {
-    period((double)us/1000000.0);
-}
-
-void FastPWM::period_us(double us) {
-    period(us/1000000.0);
-}
-
-void FastPWM::pulsewidth(double seconds) {
-    *MR=(unsigned int) (seconds * (double)F_CLK);
-    LPC_PWM1->LER |= 1<<PWMUnit;
-    _duty=seconds/_period;
-}
-
-void FastPWM::pulsewidth_ms(int ms) {
-    pulsewidth((double)ms/1000.0);
-}
-
-void FastPWM::pulsewidth_us(int us) {
-    pulsewidth((double)us/1000000.0);
-}
-
-void FastPWM::pulsewidth_us(double us) {
-    pulsewidth(us/1000000.0);
-}
-
-void FastPWM::write(double duty) {
-    _duty=duty;
-    pulsewidth(duty*_period);
-}
-
-double FastPWM::read( void ) {
-    return _duty;
-    }
-    
-FastPWM & FastPWM::operator= (double value) {
-    write(value);
-    return(*this);
-    }
-    
-FastPWM::operator double() {
-    return _duty;
-}
-    
\ No newline at end of file

diff -r 3094d3806cfc -r 923b54e7c2c1 FastPWM.h
--- a/FastPWM.h	Wed Jul 25 07:14:39 2012 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,123 +0,0 @@
-/*
-    .---.           _....._
-   /  p  `\     .-""`:     :`"-.
-   |__   - |  ,'     .     '    ',
-    ._>    \ /:      :     ;      :,
-     '-.    '\`.     .     :     '  \
-        `.   | .'._.' '._.' '._.'.  |
-          `;-\.   :     :     '   '/,__,
-          .-'`'._ '     .     : _.'.__.'
-         ((((-'/ `";--..:..--;"` \
-             .'   /           \   \
-       jgs  ((((-'           ((((-'
-       
-Yeah ASCII art turtle more fun than copyright stuff
-*/
-
-
-#include "mbed.h"
-
-
-#ifndef FASTPWM_H
-#define FASTPWM_H
-
-#ifndef F_CLK
-#define F_CLK   96000000
-#endif
-
-/** Library that allows faster and/or higher resolution PWM output
-  *
-  * Library can directly replace standard mbed PWM library. Only limitation is that the maximum PWM period is four times shorter
-  * The maximum achievable period is roughly 40 seconds, I dont think that should be a problem.
-  * Do take into account all PWM objects will run four times faster than default.
-  *
-  * Contrary to the default mbed library, this library takes doubles instead of floats. The compiler will autocast if needed,
-  * but do take into account it is done for a reason, your accuracy will otherwise be limitted by the floating point precision.
-  *
-  * In your program you can define F_CLK if you use a different clock frequency than the default one. 
-  *
-  * 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.
-  */
-class FastPWM {
-public:
-    /**
-    * Create a FastPWM object connected to the specified pin
-    *
-    * @param pin - PWM pin to connect to
-    */
-    FastPWM(PinName pin);
-    
-    /**
-    * Set the PWM period, specified in seconds (double), keeping the duty cycle the same.
-    */
-    void period(double seconds);
-    
-    /**
-    * Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
-    */
-    void period_ms(int ms);
-    
-    /**
-    * Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
-    */
-    void period_us(int us);
-    
-    /**
-    * Set the PWM period, specified in micro-seconds (double), keeping the duty cycle the same.
-    */
-    void period_us(double us);
-    
-    /**
-    * Set the PWM pulsewidth, specified in seconds (double), keeping the period the same.
-    */
-    void pulsewidth(double seconds);
-    
-    /**
-    * Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
-    */
-    void pulsewidth_ms(int ms);
-    
-    /**
-    * Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
-    */
-    void pulsewidth_us(int us);
-    
-    /**
-    * Set the PWM pulsewidth, specified in micro-seconds (double), keeping the period the same.
-    */
-    void pulsewidth_us(double us);
-    
-    /**
-    * Set the ouput duty-cycle, specified as a percentage (double)
-    *
-    * @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%).
-    */
-    void write(double duty);
-    
-    /**
-    * Return the ouput duty-cycle, specified as a percentage (double)
-    *
-    * @param return - A double value representing the output duty-cycle, specified as a percentage.
-    */
-    double read( void );
-    
-    /**
-    * An operator shorthand for write()
-    */
-    FastPWM& operator= (double value);
-    
-    /**
-    * An operator shorthand for read()
-    */
-    operator double();
-    
-private:
-    PwmOut PWMObject;
-    double _duty;
-    double _period;
-    unsigned int PWMUnit;
-    
-    __IO uint32_t *MR;
-
-};
-#endif
\ No newline at end of file

diff -r 3094d3806cfc -r 923b54e7c2c1 HighPWM.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HighPWM.cpp	Thu May 23 10:39:29 2013 +0000
@@ -0,0 +1,123 @@
+#include "HighPWM.h"
+
+HighPWM::HighPWM(PinName pin) : PWMObject(pin){
+    //Set clock source to CPU clock (without devider)
+    LPC_SC->PCLKSEL0 |= 1<<12;
+    
+    _pulsewidth = 0;
+    _period = 0;
+    
+    if (pin==p26||pin==LED1) {
+        PWMUnit=1;
+        MR=&LPC_PWM1->MR1;
+        }
+    else if (pin==p25||pin==LED2){
+        PWMUnit=2;
+        MR=&LPC_PWM1->MR2;
+        }
+    else if (pin==p24||pin==LED3){
+        PWMUnit=3;
+        MR=&LPC_PWM1->MR3;
+        }
+    else if (pin==p23||pin==LED4){
+        PWMUnit=4;
+        MR=&LPC_PWM1->MR4;
+        }
+    else if (pin==p22){
+        PWMUnit=5;
+        MR=&LPC_PWM1->MR5;
+        }
+    else if (pin==p21){
+        PWMUnit=6;
+        MR=&LPC_PWM1->MR6;
+        }
+    else
+        error("Invalid hardware PWM pin\n\r");
+    
+    frequency(10000);   // 10kHz
+}
+
+void HighPWM::frequency(double frq) 
+{
+    if ( frq>0.0 )
+        period(1.0/frq);
+}
+
+void HighPWM::period(double seconds) 
+{
+    period_ticks((unsigned int)(seconds*s_2_F_CLK+0.5));
+}
+
+void HighPWM::period_us(double us) 
+{
+    period_ticks((unsigned int)(us*us_2_F_CLK+0.5));
+}
+
+void HighPWM::period_ms(unsigned int ms) 
+{
+    period_ticks(ms*ms_2_F_CLK);
+}
+
+void HighPWM::period_us(unsigned int us) 
+{
+    period_ticks(us*us_2_F_CLK);
+}
+
+void HighPWM::period_ticks(unsigned int ticks) 
+{
+    double duty = (double)_pulsewidth/(double)_period;
+    
+    LPC_PWM1->MR0 = ticks;
+    LPC_PWM1->LER |= 1;
+    _period = ticks;
+    pulsewidth_ticks((int)(duty*(double)_period+0.5));
+}
+
+void HighPWM::pulsewidth(double seconds) 
+{
+    pulsewidth_ticks((unsigned int)(seconds*s_2_F_CLK+0.5));
+}
+
+void HighPWM::pulsewidth_us(double us) 
+{
+    pulsewidth_ticks((unsigned int)(us*us_2_F_CLK+0.5));
+}
+
+void HighPWM::pulsewidth_ms(unsigned int ms) 
+{
+    pulsewidth_ticks(ms*ms_2_F_CLK);
+}
+
+void HighPWM::pulsewidth_us(unsigned int us) 
+{
+    pulsewidth_ticks(us*us_2_F_CLK);
+}
+
+void HighPWM::pulsewidth_ticks(unsigned int ticks) 
+{
+    *MR = ticks;
+    LPC_PWM1->LER |= 1<<PWMUnit;
+    _pulsewidth = ticks;
+}
+
+void HighPWM::write(double duty) 
+{
+    pulsewidth_ticks((int)(duty*(double)_period+0.5));
+}
+
+double HighPWM::read( void ) 
+{
+    return (double)_pulsewidth/(double)_period;
+}
+    
+HighPWM & HighPWM::operator= (double value) 
+{
+    write(value);
+    return(*this);
+}
+    
+HighPWM::operator double() 
+{
+    return read();
+}
+    
\ No newline at end of file

diff -r 3094d3806cfc -r 923b54e7c2c1 HighPWM.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HighPWM.h	Thu May 23 10:39:29 2013 +0000
@@ -0,0 +1,132 @@
+#ifndef HighPWM_H
+#define HighPWM_H
+
+#include "mbed.h"
+
+#ifndef F_CLK
+#define F_CLK   96000000
+#endif
+
+#define us_2_F_CLK (F_CLK/1000000)
+#define ms_2_F_CLK (F_CLK/1000)
+#define s_2_F_CLK (F_CLK)
+
+/** Library that allows faster and/or higher resolution PWM output
+  *
+  * This library is based original on FastPWM by Erik Olieman but without floating point (double) calculation in each call of pulsewidth_xx.
+  * This change was nessecary to get a performant motion controller.
+  *
+  * Library can directly replace standard mbed PWM library. Only limitation is that the maximum PWM period is four times shorter
+  * The maximum achievable period is roughly 40 seconds, I dont think that should be a problem.
+  * Do take into account all PWM objects (based on defailt PWM lib) will run four times faster than default.
+  *
+  * Contrary to the default mbed library, this library takes doubles instead of floats. The compiler will autocast if needed,
+  * but do take into account it is done for a reason, your accuracy will otherwise be limitted by the floating point precision.
+  *
+  * Using this library for a RC servo the resolution of steps (min to max) is increased from 1000 to 96000.
+  *
+  * This library can be also used as a analoge output (with external low-pass filter) with a frequency of e.g. 20kHz and a resolution 4800 steps (similar to a 12 bit DAC) instead of 50 steps (similar to a 5 bit DAC) on original PWM lib.
+  *
+  * In your program you can define F_CLK if you use a different clock frequency than the default one. 
+  *
+  * 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.
+  */
+class HighPWM {
+public:
+    /**
+    * Create a HighPWM object connected to the specified pin
+    *
+    * @param pin - PWM pin to connect to
+    */
+    HighPWM(PinName pin);
+    
+    /**
+    * Set the PWM frequency, specified in Hz (double), keeping the duty cycle the same.
+    */
+    void frequency(double frq);
+    
+    /**
+    * Set the PWM period, specified in seconds (double), keeping the duty cycle the same.
+    */
+    void period(double seconds);
+    
+    /**
+    * Set the PWM period, specified in micro-seconds (double), keeping the duty cycle the same.
+    */
+    void period_us(double us);
+    
+    /**
+    * Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
+    */
+    void period_ms(unsigned int ms);
+    
+    /**
+    * Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
+    */
+    void period_us(unsigned int us);
+    
+    /**
+    * Set the PWM period, specified in cpu ticks based on 96MHz (int), keeping the duty cycle the same.
+    */
+    void period_ticks(unsigned int ticks);
+    
+    /**
+    * Set the PWM pulsewidth, specified in seconds (double), keeping the period the same.
+    */
+    void pulsewidth(double seconds);
+    
+    /**
+    * Set the PWM pulsewidth, specified in micro seconds (double), keeping the period the same.
+    */
+    void pulsewidth_us(double us);
+    
+    /**
+    * Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
+    */
+    void pulsewidth_ms(unsigned int ms);
+    
+    /**
+    * Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
+    */
+    void pulsewidth_us(unsigned int us);
+    
+    /**
+    * Set the PWM pulsewidth, specified in cpu ticks based on 96MHz (int), keeping the period the same.
+    */
+    void pulsewidth_ticks(unsigned int ticks);
+    
+    /**
+    * Set the ouput duty-cycle, specified as a percentage (double)
+    *
+    * @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%).
+    */
+    void write(double duty);
+    
+    /**
+    * Return the ouput duty-cycle, specified as a percentage (double)
+    *
+    * @param return - A double value representing the output duty-cycle, specified as a percentage.
+    */
+    double read( void );
+    
+    /**
+    * An operator shorthand for write()
+    */
+    HighPWM& operator= (double value);
+    
+    /**
+    * An operator shorthand for read()
+    */
+    operator double();
+    
+private:
+    PwmOut PWMObject;
+    //double _duty;
+    int _period;
+    int _pulsewidth;
+    unsigned int PWMUnit;
+    
+    __IO uint32_t *MR;
+
+};
+#endif
\ No newline at end of file