sanguino/cores/arduino/wiring_analog.c

changeset 2
b373b0288715
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sanguino/cores/arduino/wiring_analog.c	Thu Jul 07 12:23:34 2016 +0200
@@ -0,0 +1,282 @@
+/*
+  wiring_analog.c - analog input and output
+  Part of Arduino - http://www.arduino.cc/
+
+  Copyright (c) 2005-2006 David A. Mellis
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General
+  Public License along with this library; if not, write to the
+  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+  Boston, MA  02111-1307  USA
+
+  Modified 28 September 2010 by Mark Sproul
+
+  $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $
+*/
+
+#include "wiring_private.h"
+#include "pins_arduino.h"
+
+uint8_t analog_reference = DEFAULT;
+
+void analogReference(uint8_t mode)
+{
+	// can't actually set the register here because the default setting
+	// will connect AVCC and the AREF pin, which would cause a short if
+	// there's something connected to AREF.
+	analog_reference = mode;
+}
+
+int analogRead(uint8_t pin)
+{
+	uint8_t low, high;
+
+#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
+	if (pin >= 54) pin -= 54; // allow for channel or pin numbers
+#elif defined(__AVR_ATmega32U4__)
+	if (pin >= 18) pin -= 18; // allow for channel or pin numbers
+#elif defined(__AVR_ATmega1284__) || defined(__AVR_ATmega644p__)
+	if (pin >= 24) pin -= 24; // allow for channel or pin numbers
+#else
+	if (pin >= 14) pin -= 14; // allow for channel or pin numbers
+#endif
+	
+#if defined(__AVR_ATmega32U4__)
+	pin = analogPinToChannel(pin);
+	ADCSRB = (ADCSRB & ~(1 << MUX5)) | (((pin >> 3) & 0x01) << MUX5);
+#elif defined(ADCSRB) && defined(MUX5)
+	// the MUX5 bit of ADCSRB selects whether we're reading from channels
+	// 0 to 7 (MUX5 low) or 8 to 15 (MUX5 high).
+	ADCSRB = (ADCSRB & ~(1 << MUX5)) | (((pin >> 3) & 0x01) << MUX5);
+#endif
+  
+	// set the analog reference (high two bits of ADMUX) and select the
+	// channel (low 4 bits).  this also sets ADLAR (left-adjust result)
+	// to 0 (the default).
+#if defined(ADMUX)
+	ADMUX = (analog_reference << 6) | (pin & 0x07);
+#endif
+
+	// without a delay, we seem to read from the wrong channel
+	//delay(1);
+
+#if defined(ADCSRA) && defined(ADCL)
+	// start the conversion
+	sbi(ADCSRA, ADSC);
+
+	// ADSC is cleared when the conversion finishes
+	while (bit_is_set(ADCSRA, ADSC));
+
+	// we have to read ADCL first; doing so locks both ADCL
+	// and ADCH until ADCH is read.  reading ADCL second would
+	// cause the results of each conversion to be discarded,
+	// as ADCL and ADCH would be locked when it completed.
+	low  = ADCL;
+	high = ADCH;
+#else
+	// we dont have an ADC, return 0
+	low  = 0;
+	high = 0;
+#endif
+
+	// combine the two bytes
+	return (high << 8) | low;
+}
+
+// Right now, PWM output only works on the pins with
+// hardware support.  These are defined in the appropriate
+// pins_*.c file.  For the rest of the pins, we default
+// to digital output.
+void analogWrite(uint8_t pin, int val)
+{
+	// We need to make sure the PWM output is enabled for those pins
+	// that support it, as we turn it off when digitally reading or
+	// writing with them.  Also, make sure the pin is in output mode
+	// for consistenty with Wiring, which doesn't require a pinMode
+	// call for the analog output pins.
+	pinMode(pin, OUTPUT);
+	if (val == 0)
+	{
+		digitalWrite(pin, LOW);
+	}
+	else if (val == 255)
+	{
+		digitalWrite(pin, HIGH);
+	}
+	else
+	{
+		switch(digitalPinToTimer(pin))
+		{
+			// XXX fix needed for atmega8
+			#if defined(TCCR0) && defined(COM00) && !defined(__AVR_ATmega8__)
+			case TIMER0A:
+				// connect pwm to pin on timer 0
+				sbi(TCCR0, COM00);
+				OCR0 = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR0A) && defined(COM0A1)
+			case TIMER0A:
+				// connect pwm to pin on timer 0, channel A
+				sbi(TCCR0A, COM0A1);
+				OCR0A = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR0A) && defined(COM0B1)
+			case TIMER0B:
+				// connect pwm to pin on timer 0, channel B
+				sbi(TCCR0A, COM0B1);
+				OCR0B = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR1A) && defined(COM1A1)
+			case TIMER1A:
+				// connect pwm to pin on timer 1, channel A
+				sbi(TCCR1A, COM1A1);
+				OCR1A = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR1A) && defined(COM1B1)
+			case TIMER1B:
+				// connect pwm to pin on timer 1, channel B
+				sbi(TCCR1A, COM1B1);
+				OCR1B = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR2) && defined(COM21)
+			case TIMER2:
+				// connect pwm to pin on timer 2
+				sbi(TCCR2, COM21);
+				OCR2 = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR2A) && defined(COM2A1)
+			case TIMER2A:
+				// connect pwm to pin on timer 2, channel A
+				sbi(TCCR2A, COM2A1);
+				OCR2A = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR2A) && defined(COM2B1)
+			case TIMER2B:
+				// connect pwm to pin on timer 2, channel B
+				sbi(TCCR2A, COM2B1);
+				OCR2B = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR3A) && defined(COM3A1)
+			case TIMER3A:
+				// connect pwm to pin on timer 3, channel A
+				sbi(TCCR3A, COM3A1);
+				OCR3A = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR3A) && defined(COM3B1)
+			case TIMER3B:
+				// connect pwm to pin on timer 3, channel B
+				sbi(TCCR3A, COM3B1);
+				OCR3B = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR3A) && defined(COM3C1)
+			case TIMER3C:
+				// connect pwm to pin on timer 3, channel C
+				sbi(TCCR3A, COM3C1);
+				OCR3C = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR4A)
+			case TIMER4A:
+				//connect pwm to pin on timer 4, channel A
+				sbi(TCCR4A, COM4A1);
+				#if defined(COM4A0)		// only used on 32U4
+				cbi(TCCR4A, COM4A0);
+				#endif
+				OCR4A = val;	// set pwm duty
+				break;
+			#endif
+			
+			#if defined(TCCR4A) && defined(COM4B1)
+			case TIMER4B:
+				// connect pwm to pin on timer 4, channel B
+				sbi(TCCR4A, COM4B1);
+				OCR4B = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR4A) && defined(COM4C1)
+			case TIMER4C:
+				// connect pwm to pin on timer 4, channel C
+				sbi(TCCR4A, COM4C1);
+				OCR4C = val; // set pwm duty
+				break;
+			#endif
+				
+			#if defined(TCCR4C) && defined(COM4D1)
+			case TIMER4D:				
+				// connect pwm to pin on timer 4, channel D
+				sbi(TCCR4C, COM4D1);
+				#if defined(COM4D0)		// only used on 32U4
+				cbi(TCCR4C, COM4D0);
+				#endif
+				OCR4D = val;	// set pwm duty
+				break;
+			#endif
+
+							
+			#if defined(TCCR5A) && defined(COM5A1)
+			case TIMER5A:
+				// connect pwm to pin on timer 5, channel A
+				sbi(TCCR5A, COM5A1);
+				OCR5A = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR5A) && defined(COM5B1)
+			case TIMER5B:
+				// connect pwm to pin on timer 5, channel B
+				sbi(TCCR5A, COM5B1);
+				OCR5B = val; // set pwm duty
+				break;
+			#endif
+
+			#if defined(TCCR5A) && defined(COM5C1)
+			case TIMER5C:
+				// connect pwm to pin on timer 5, channel C
+				sbi(TCCR5A, COM5C1);
+				OCR5C = val; // set pwm duty
+				break;
+			#endif
+
+			case NOT_ON_TIMER:
+			default:
+				if (val < 128) {
+					digitalWrite(pin, LOW);
+				} else {
+					digitalWrite(pin, HIGH);
+				}
+		}
+	}
+}
+

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