Uno as Duemilanove replacement - Port manipulation problem

Using Arduino Installation & Troubleshooting
#1

Hello,

I’ve bought Uno (as the Duemilanove’s are discontinued) for my project.

I use port manipulation commands (DDRB and PINB) in my project and they are not working anymore on the Uno. As far as I now, there is nothing changed to the digital IO’s.

When I exchanged the Atmel 328 chips, I was able to read the inputs with the Duemilanove board and Uno Atmel chip! So, the Uno Atmel chip seems to be OK. But I was not able to read inputs with the Uno board and the Duemilanove Atmel chip.

Have anybody else experienced this or knows a solution?

This is the code that I’m using:

#include "pins_arduino.h"

int lastDigital = 0x0000;

void setup() {
  DDRD &= B00000011; // 1-2 serial port (don't set) | 3-8 digital IN
  DDRB &= B11000000; // 1-2 digital IN  | 3-5 board ID | 6 sync | 7-8 nothing (don't set)

  Serial.begin(19200);
}
 
void loop() {
  byte temp1 = PIND & B11111100;
  byte temp2 = PINB & B00111111;
  
    int result = 0xf800 | (unsigned(temp1) >> 2) | (temp2 << 6);
  
    if (result != lastDigital) {
      if ((result & 0x00ff) != 0x0000) {
        Serial.write(result >> 8);
        Serial.write(result);   
        Serial.write((byte)0x00);
        Serial.write((byte)0xff);
      }
      
      lastDigital = result;
  }  
}
#2

What do you mean “doesn’t work”?

In terms of providing a connection between the ATmega328 chip and the header pins, there is no difference between an Uno board and Duemilanove board.

#3

James,

"doesn't work": if I set a 5v signal on pin 2, nothing is written over the serial line. This still works on the Duemilanove with the same piece of software.

If I use the arduinolib function digitalRead, everything works fine. But it's to slow for my application.

The schematics of both board are equal regarding the header pins. So, I don't know why it's not working on the Uno. Is there something changed in the bootloader?

#4

The bootloader has nothing to do with your code.

Are you leaving the input pin floating or are you using a pull-down?

#5

For testing, I've put shortly 5v on pin 2 and connected pin 2 to ground. It's working on the Duemilanove board.

I was thinking that my Uno board has a manufacturing issue but I've tested another Uno board and it had the same result.

#6