From http://www.arduino.cc/en/Reference/PortManipulation it was said PORTD can be used to control pin 0-7. However, sadly it does not work for me. digitalWrite and pinMode works well. But DDRD and PORTD has no response at all.
I start suspecting the document and trying other ports, and happily find PORTE works for pin 2-3. But not for the others. I think now it is time to test other ports and make a new mapping.
By testing, here's the ports corresponding to pin of Mega2560. It seems a little weird and I don't know why. If you have the same problem, I would suggest you to also try different PORT names on your board.
Hope this would help others that encounter the same problem.
| PIN number | PORT |
|---|---|
| 2 | PORTE (0x10) |
| 3 | PORTE (0x20) |
| 4 | PORTG (0x20) |
| 5 | PORTE (0x08) |
| 6 | PORTH (0x08) |
| 7 | PORTH (0x10) |
| 8 | PORTH (0x20) |
| 9 | PORTH (0x40) |
| 10 | PORTB (0x10) |
| 11 | PORTB (0x20) |
| 12 | PORTB (0x40) |
| 13 | PORTB (0x80) |
| 22-29 | PORTA (0x01-0x80) |
| 30-37 | PORTC (0x80-0x01) |
| 38-45 | PORTD (0x80-0x01) |
| 46-53 | <NOT_FOUND> |
Hi,
ReplyDeletethis post helped me a lot!!! I searched in the internet a whole day, but this is the only post which helped me out. I think that, this should be included on the arduino reference page.
Btw, Regarding to the missing Pins 46-53M:
Maybe the table at the bottom is a help http://arduino.cc/en/Hacking/PinMapping2560
Regarding to the table and if i checked the coherence right,
PIN 50-53 should be in PORTB,
PIN 42-49 should be in PORTL, and so on
but i hadnt the time right now to check it.
Thanks a lot!
BTW PORTF is used for pins A0 to A7
ReplyDeleteOH Yes its very helpful to know about the PORT register of ATMEGA2560
ReplyDeleteby using these port i will write a code to print minute counts on seven segment display
i have used TWO SEVENSEGMENTS prints 0-59,after that reset,compatible with TIMER1 on ARDUINO board
CODE IS HERE
// Arduino timer CTC interrupt example
//With seven segment display
// avr-libc library includes
#include
#include
#define LEDPIN 13
//variable for switch state2
int y=11;
//variable for switch state1
int x=2;
void setup()
{
//PORT A FOR SEGMENT 1
DDRA = B11111111; //initialize port pins as output 22-29
//PORT C FOR SEGMENT 2
DDRC = B11111111; //initialize port pins as output 37-30
//sets both segment as zero
PORTA = B0111111;
PORTC = B0111111;
pinMode(LEDPIN, OUTPUT);
// initialize Timer1
//for timer configuration visit "https://arduinodiy.wordpress.com/2012/02/28/timer-interrupts/"
cli(); // disable global interrupts
TCCR1A = 0; // set entire TCCR1A register to 0
TCCR1B = 0; // same for TCCR1B
// set compare match register to desired timer count:
OCR1A = 15624;
// turn on CTC mode:
TCCR1B |= (1 << WGM12);
// Set CS10 and CS12 bits for 1024 prescaler:
TCCR1B |= (1 << CS10);
TCCR1B |= (1 << CS12);
// enable timer compare interrupt:
TIMSK1 |= (1 << OCIE1A);
// enable global interrupts:
sei();
}
void loop()
{
// main program
}
//create a function for counts 0-59,after that reset
void counts(int chk)
{
if(chk<=10)
{
switch (chk) //Ist switch state is to print 1-9 on segment2
{
case 2:
{
//print seg2=1
PORTC = B0000110;
x++;
}break;
case 3:
{
//print seg2=2
PORTC = B1011011;
x++;
}break;
case 4:
{
//print seg2=3
PORTC = B1001111;
x++;
}break;
case 5:
{
//print seg2=4
PORTC = B1100110;
x++;
}break;
case 6:
{
//print seg2=5
PORTC = B1101101;
x++;
}break;
case 7:
{
//print seg2=6
PORTC = B1111101;
x++;
}break;
case 8:
{
//print seg2=7
PORTC = B0000111;
x++;
}break;
case 9:
{
//print seg2=8
PORTC = B1111111;
x++;
}break;
case 10:
{
//print seg2=9
PORTC = B1101111;
x++;
//y=11;
}break;
}
}
else
{
switch(y) //second state is to print1-5 on segment1
{
case 11:
{
//seg1=1,seg2=0
PORTA = B0000110;
PORTC = B0111111;
x=2;
y++;
}break;
case 12:
{
//seg1=2,seg2=0
PORTA = B1011011;
PORTC = B0111111;
x=2;
y++;
}break;
case 13:
{
//seg1=3,seg2=0
PORTA = B1001111;
PORTC = B0111111;
x=2;
y++;
}break;
case 14:
{
//seg1=4,seg2=0
PORTA = B1100110;
PORTC = B0111111;
x=2;
y++;
}break;
case 15:
{
//seg1=5,seg2=0
PORTA = B1101101;
PORTC = B0111111;
x=2;
y++;
}break;
case 16:
{
//seg1=0,seg2=0
PORTA = B0111111;
PORTC = B0111111;
x=2;
y=11;
}break;
}
}
}
ISR(TIMER1_COMPA_vect)
{
digitalWrite(LEDPIN, !digitalRead(LEDPIN));
counts(x);//call counts function
}
So I tried implementing Port Manipulation like this for a Mega 2560 but get this error with this code
ReplyDeletevoid setup(){
PORTA = B0000000;
PORTC = B0000000;
}
void loop(){
PORTA = B1000110;
PortC = B0111000;
delay(1000);
PortA = B0100000;
delay(500);
PORTA = B1110000;
PortC = B0001110;
delay(1000);
PortA = B0001000;
delay(500);
PORTA = B0011100;
PortC = B1100010;
delay(1000);
PortA = B0000100;
delay(500);
PORTA = B000111;
PortC = B111000;
delay(1000);
PortA = B1000000;
delay(500);
}
error exit status 1
'PortC' was not declared in this scope
Hi. try 'PORTC' instead of 'PortC' the compiler is case sensitive...
Delete