2015-06-23 12:42:35 -07:00

262 lines
6.2 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
$Id: wiring.c 248 2007-02-03 15:36:30Z mellis $
Modified 28-08-2009 for attiny84 R.Wiersma
Modified 14-10-2009 for attiny45 Saposoft
Corrected 17-05-2010 for ATtiny84 B.Cook
*/
#include "wiring_private.h"
#include "pins_arduino.h"
#ifndef DEFAULT
//For those with no ADC, need to define default.
#define DEFAULT (0)
#endif
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.
// fix? Validate the mode?
analog_reference = mode;
}
int analogRead(uint8_t pin)
{
#if defined( NUM_DIGITAL_PINS )
if ( pin >= NUM_DIGITAL_PINS ) pin -= NUM_DIGITAL_PINS; // allow for channel or pin numbers
#endif
// fix? Validate pin?
if(pin >= NUM_ANALOG_INPUTS) return 0; //Not a valid pin.
//if(pin < 4) return 9; //Not a valid pin.
#ifndef ADCSRA
return digitalRead(analogInputToDigitalPin(pin)) ? 1023 : 0; //No ADC, so read as a digital pin instead.
#endif
#if defined(ADMUX)
#if defined(MUX4)
ADMUX = ((analog_reference & 0x03) << REFS0) | ((pin & 0x1F) << MUX0); //select the channel and reference
#elif defined(MUX3)
ADMUX = ((analog_reference & 0x03) << REFS0) | ((pin & 0x0F) << MUX0); //select the channel and reference
#else
ADMUX = ((analog_reference & 0x03) << REFS0) | ((pin & 0x07) << MUX0); //select the channel and reference
#endif
#endif
#if defined(REFS2)
ADMUX |= (((analog_reference & 0x04) >> 2) << REFS2); //some have an extra reference bit in a weird position.
#endif
#if defined(HAVE_ADC) && HAVE_ADC
sbi(ADCSRA, ADSC); //Start conversion
while(ADCSRA & (1<<ADSC)); //Wait for conversion to complete.
uint8_t low = ADCL;
uint8_t high = ADCH;
return (high << 8) | low;
#else
return LOW;
#endif
}
void pwmReset()
{
cbi(TCCR1D, OC1AV);
cbi(TCCR1D, OC1AU);
cbi(TCCR1D, OC1AW);
cbi(TCCR1D, OC1AX);
cbi(TCCR1D, OC1BV);
cbi(TCCR1D, OC1BU);
cbi(TCCR1D, OC1BW);
cbi(TCCR1D, OC1BX);
}
void pwmWrite(uint8_t channel, int val)
{
if( channel == TIMER1A){
// connect pwm to pin on timer 1, channel A
sbi(TCCR1A, COM1A1);
sbi(TCCR1A, WGM10);
cbi(TCCR1A, COM1A0);
sbi(TCCR1B, WGM10);
sbi(TCCR1B, CS11);
//sbi(TCCR1B, CS10);
OCR1A = val; // set pwm duty
} else if( channel == TIMER1B){
// connect pwm to pin on timer 1, channel B
sbi(TCCR1A, COM1B1);
sbi(TCCR1A, WGM10);
cbi(TCCR1A, COM1B0);
sbi(TCCR1B, WGM10);
sbi(TCCR1B, CS11);
//sbi(TCCR1B, CS10);
OCR1B = val; // set pwm duty
}
}
void pwmConnect(uint8_t pin)
{
pinMode(pin,OUTPUT);
if(pin == 2)
sbi(TCCR1D, OC1AV);
else if(pin == 0)
sbi(TCCR1D, OC1AU);
// cbi(TCCR1D, OC1AW);//used by crystal
else if(pin == 3)
sbi(TCCR1D, OC1AX);
else if(pin == 4)
sbi(TCCR1D, OC1BV);
else if(pin == 1)
sbi(TCCR1D, OC1BU);
// cbi(TCCR1D, OC1BW);//used by crystal
// sbi(TCCR1D, OC1BX);//reset pin
}
void pwmDisconnect(uint8_t pin)
{
pinMode(pin,OUTPUT);
if(pin == 2)
cbi(TCCR1D, OC1AV);
else if(pin == 0)
cbi(TCCR1D, OC1AU);
// cbi(TCCR1D, OC1AW);//used by crystal
else if(pin == 3)
cbi(TCCR1D, OC1AX);
else if(pin == 4)
cbi(TCCR1D, OC1BV);
else if(pin == 1)
cbi(TCCR1D, OC1BU);
// cbi(TCCR1D, OC1BW);//used by crystal
// cbi(TCCR1D, OC1BX);//reset pin
}
// 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
{
uint8_t timer = digitalPinToTimer(pin);
if( timer == TIMER0A){
// connect pwm to pin 8 on timer 0, channel A
sbi(TCCR0A, COM0A1);
cbi(TCCR0A, COM0A0);
sbi(TCCR0A, WGM01);
sbi(TCCR0A, WGM00);
OCR0A = val; // set pwm duty
} else
if( timer == TIMER1A){
// connect pwm to pin on timer 1, channel A
sbi(TCCR1A, COM1A1);
sbi(TCCR1A, WGM10);
cbi(TCCR1A, COM1A0);
sbi(TCCR1B, WGM10);
sbi(TCCR1B, CS11);
//sbi(TCCR1B, CS10);
cbi(TCCR1D, OC1AV);
cbi(TCCR1D, OC1AU);
cbi(TCCR1D, OC1AW);
cbi(TCCR1D, OC1AX);
if(pin == 2)
sbi(TCCR1D, OC1AV);
else if(pin == 0)
sbi(TCCR1D, OC1AU);
else if(pin == 3)
sbi(TCCR1D, OC1AX);
OCR1A = val; // set pwm duty
} else
if( timer == TIMER1B){
// connect pwm to pin on timer 1, channel B
sbi(TCCR1A, COM1B1);
sbi(TCCR1A, WGM10);
cbi(TCCR1A, COM1B0);
sbi(TCCR1B, WGM10);
sbi(TCCR1B, CS11);
//sbi(TCCR1B, CS10);
cbi(TCCR1D, OC1BV);
cbi(TCCR1D, OC1BU);
cbi(TCCR1D, OC1BW);
cbi(TCCR1D, OC1BX);
if(pin == 4)
sbi(TCCR1D, OC1BV);
else if(pin == 1)
sbi(TCCR1D, OC1BU);
OCR1B = val; // set pwm duty
} else
{
if (val < 128)
{
digitalWrite(pin, LOW);
}
else
{
digitalWrite(pin, HIGH);
}
}
}
}