millis() not working on DUE

Official Hardware Mega Due
1

Hello everyone,

I have two boards: 1. Arduino UNO R3 and 2. Arduino DUE R3-E.
I am using Arduino 1.5.7 on Windows 8.1 64 bit
My problem is with a piece of code that works fine on UNO but not on DUE.

/*Program execution time*/

unsigned long time;
unsigned long number = 1234567UL;

void setup() 
{ 
  Serial.begin(9600);  
  for(unsigned long counter = 1UL; counter != number + 1; counter++)
  {
    if(number % counter == 0)
    {
      Serial.println(counter); //Print the factors
    }
  }
  time = millis();
  Serial.print("Time: ");
  Serial.println(time / 1000); //Print time in seconds
}

void loop() 
{
 ;  
}

On the UNO the output on the serial monitor:

1
127
9721
1234567
Time: 47

But on DUE the same code generates a compile time error:

Arduino: 1.5.7 (Windows 8), Board: "Arduino Due (Programming Port)"

Build options changed, rebuilding all

Progexecutiontiming.ino:3:15: error: 'long unsigned int time' redeclared as different kind of symbol
In file included from c:\program files (x86)\arduino\hardware\tools\gcc-arm-none-eabi-4.8.3-2014q1\arm-none-eabi\include\stdlib.h:11:0,
from C:\Program Files (x86)\Arduino\hardware\arduino\sam\cores\arduino/Arduino.h:24,
from Progexecutiontiming.ino:3:
c:\program files (x86)\arduino\hardware\tools\gcc-arm-none-eabi-4.8.3-2014q1\arm-none-eabi\include\time.h:47:11: error: previous declaration of 'time_t time(time_t*)'
time_t _EXFUN(time, (time_t _timer));
^
Progexecutiontiming.ino: In function 'void setup()':
Progexecutiontiming.ino:16:8: error: assignment of function 'time_t time(time_t)'
Progexecutiontiming.ino:16:8: error: cannot convert 'uint32_t {aka long unsigned int}' to 'time_t(time_t*) {aka long int(long int*)}' in assignment
Progexecutiontiming.ino:18:25: error: invalid operands of types 'time_t(time_t*) {aka long int(long int*)}' and 'int' to binary 'operator/'

Any help would be much appreciated. Thanks.

2

This is nothing to do with millis() as an examination of the error
message would show. The symbol "time" is predeclared on the Due,
you need to give it a different name such as "my_time".

3

Thank you MarkT. Changing the name of the variable worked. Just one more confusion! In your post you wrote that "time" is predeclared in DUE ( I am guessing like a keyword ). Can you please give me some detailed information on it. And what other keywords are there for DUE. A link to any reference would be nice. Thanks :slight_smile:

4

I just grepped the sources - there's a " time_t time ; " declared somewhere

5

time() is a C Standard library function, declared in c:\program files (x86)\arduino\hardware\tools\gcc-arm-none-eabi-4.8.3-2014q1\arm-none-eabi\include\time.h (like the error message says).

I don't know of a definitive list of reserved words, but a guide to C standard functions should give clues on some things to avoid http://www.acm.uiuc.edu/webmonkeys/book/c_guide/

6

Thank you MarkT and bobcousins. Trying out the c reserved words and checking the header files in the arduino directory. I will try to create a list.

7

You'll need to grep libsam too! And then there's CMSIS

8

Hello polysysdelta,

can you tell us where you got the DUE R3-E? There is a problem with the DUE R3, and the DUE R3-E seems to solve this problem: Due won't start after power off-on, have to reset - Arduino Due - Arduino Forum.

Vile

9

MarkT:
This is nothing to do with millis() as an examination of the error
message would show. The symbol "time" is predeclared on the Due,
you need to give it a different name such as "my_time".

THANKS!!