259 lines
6.5 KiB
C
259 lines
6.5 KiB
C
/*
|
|
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
|
|
#else
|
|
if (pin >= 14) pin -= 14; // allow for channel or pin numbers
|
|
#endif
|
|
|
|
#if 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) && defined(COM4A1)
|
|
case TIMER4A:
|
|
// connect pwm to pin on timer 4, channel A
|
|
sbi(TCCR4A, COM4A1);
|
|
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(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);
|
|
}
|
|
}
|
|
}
|
|
}
|