Initial Arduino IDE based on Processing.

2025-06-17 22:23:10 +03:00 · 2005-08-25 21:06:28 +00:00
commit 9fc5aa63f6
373 changed files with 71081 additions and 0 deletions
--- a/build/shared/lib/avrlib/pwmsw.c
+++ b/build/shared/lib/avrlib/pwmsw.c
@ -0,0 +1,153 @@
+/*! \file pwmsw.c \brief Software interrupt-driven multi-output PWM function library. */
+//*****************************************************************************
+//
+// File Name	: 'pwmsw.c'
+// Title		: Software interrupt-driven multi-output PWM function library
+// Author		: Pascal Stang - Copyright (C) 2002
+// Created		: 7/20/2002
+// Revised		: 7/31/2002
+// Version		: 0.1
+// Target MCU	: Atmel AVR Series
+// Editor Tabs	: 4
+//
+// WARNING: this PWM library does not work perfectly.  It has known and
+//	understood problems when two or more PWM outputs are set to nearly the
+//	same duty cycle.  IT MAY NOT BE WORTH USING!  YOU HAVE BEEN WARNED!
+//
+// This code is distributed under the GNU Public License
+//		which can be found at http://www.gnu.org/licenses/gpl.txt
+//
+//*****************************************************************************
+
+#ifndef WIN32
+	#include <avr/io.h>
+#endif
+
+#include "global.h"
+#include "pwmsw.h"
+
+// Program ROM constants
+
+// Global variables
+// PWM channel registers
+u16 PosTics;
+u16 PeriodTics;
+u08 Channel;
+SwPwmChannelType SwPwmChannels[SWPWM_NUM_CHANNELS];
+
+// functions
+
+// initializes software PWM system
+void pwmswInit(u16 periodTics)
+{
+	u08 index;
+
+	// attach the software PWM service routine to timer1 output compare A
+	timerAttach(TIMER1OUTCOMPAREA_INT, pwmswService);
+	// set PeriodTics
+	PeriodTics = periodTics;
+	// set PosTics
+	PosTics = 0;
+	// clear channels
+	for(index=0; index<SWPWM_NUM_CHANNELS; index++)
+	{
+		SwPwmChannels[index].duty = 0;
+		SwPwmChannels[index].setduty = 0;
+	}
+	// set initial interrupt time
+	u16 OCValue;
+	// read in current value of output compare register OCR1A
+	OCValue =  inb(OCR1AL);		// read low byte of OCR1A
+	OCValue += inb(OCR1AH)<<8;	// read high byte of OCR1A
+	// increment OCR1A value by nextTics
+	OCValue += PeriodTics; 
+	// set future output compare time to this new value
+	outb(OCR1AH, (OCValue>>8));			// write high byte
+	outb(OCR1AL, (OCValue & 0x00FF));	// write low byte
+
+	// enable the timer1 output compare A interrupt
+	sbi(TIMSK, OCIE1A);
+}
+
+// turns off software PWM system
+void pwmswOff(void)
+{
+	// disable the timer1 output compare A interrupt
+	cbi(TIMSK, OCIE1A);
+	// detach the service routine
+	timerDetach(TIMER1OUTCOMPAREA_INT);
+}
+
+// set duty on channel
+void pwmswPWMSet(u08 channel, u16 duty)
+{
+	// compare with max value of PeriodTics
+	duty = MIN(duty, PeriodTics);
+	SwPwmChannels[channel].setduty = duty;
+}
+
+void pwmswService(void)
+{
+	u16 nextTics=PeriodTics;
+	u08 index;
+
+	// check for beginning of period
+	if(PosTics == 0)
+	{
+		// examine all channels
+		for(index=0; index<SWPWM_NUM_CHANNELS; index++)
+		{
+			// transfer set-duty to active-duty
+			SwPwmChannels[index].duty = SwPwmChannels[index].setduty;
+			// find next channel event to schedule
+			//		if no channel has a duty setting greater than 0 (PosTics);
+			//		nextTics will remain at PeriodTics for the next cycle
+			if(SwPwmChannels[index].duty)
+			{
+				nextTics = MIN(nextTics, SwPwmChannels[index].duty);
+				// set all non-zero channels to on
+				outb(SWPWMPORT, inb(SWPWMPORT) | (1<<index));
+			}
+		}
+	}
+	else
+	{
+		// examine all channels
+		for(index=0; index<SWPWM_NUM_CHANNELS; index++)
+		{
+			// check if we have a duty cycle match
+			if(PosTics == SwPwmChannels[index].duty)
+			{
+				// clear output channel
+				outb(SWPWMPORT, inb(SWPWMPORT) & ~(1<<index));
+			}
+			// find next channel event to schedule
+			//		if no channel has a duty setting greater than PosTics;
+			//		nextTics will remain at PeriodTics and is handled below
+			if(SwPwmChannels[index].duty > PosTics)
+				nextTics = MIN(nextTics, SwPwmChannels[index].duty-PosTics);
+		}
+		if(nextTics == PeriodTics)
+		{
+			// no more channels to schedule
+			// schedule next cycle
+			nextTics = PeriodTics - PosTics;
+		}
+	}
+
+	// schedule next interrupt
+	u16 OCValue;
+	// read in current value of output compare register OCR1A
+	OCValue =  inb(OCR1AL);		// read low byte of OCR1A
+	OCValue += inb(OCR1AH)<<8;	// read high byte of OCR1A
+	// increment OCR1A value by nextTics
+	OCValue += nextTics;
+//	OCR1A+=nextTics;
+	// set future output compare time to this new value
+	outb(OCR1AH, (OCValue>>8));			// write high byte
+	outb(OCR1AL, (OCValue & 0x00FF));	// write low byte
+	// set our new tic position
+	PosTics += nextTics;
+	if(PosTics >= PeriodTics) PosTics -= PeriodTics;
+}
+