bugfix read analog

This commit is contained in:
harald 2014-06-02 13:46:54 +02:00
parent b398ab9288
commit 45dee77092

View file

@ -26,6 +26,7 @@
#include "wiring_private.h"
#include "pins_arduino.h"
#include "adc.h"
uint8_t analog_reference = DEFAULT;
@ -39,59 +40,7 @@ void analogReference(uint8_t 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_ATmega1284P__) || defined(__AVR_ATmega644P__)
if (pin >= 24) pin -= 24; // allow for channel or pin numbers
#elif defined(__AVR_ATmega128RFA1__)
if (pin >= 26) pin -= 26; // 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;
return readADC(pin);
}
// Right now, PWM output only works on the pins with