http://arduino.cc/en/Main/ReleaseNotes
But I can't find within any library file where it is referenced.
I wanted to peek and see what it actually does, but I was unable to find it.

Hi,

With the new F() function, I can see how easy it would be to print from Flash without using PROGMEM.
How can I use this function to print a progmem array too?

Thank you,
RI

Ah-ha!!!
I think you nailed!!!
I don't have any board to test, but I'm pretty sure this is the issue.
Thanks a lot!!

Nor can I upload it to my Mega2560:

Code:

Binary sketch size: 27010 bytes (of a 258048 byte maximum)
avrdude: verification error, first mismatch at byte 0x0483
         0x9e != 0xff
avrdude: verification error; content mismatch

Thanks for the explanation, but even with very little program size, it still has issues.
The total size of the sketch is 27010, which is below the 64K you mentioned.
Does what you stated still apply even though the size is less than 64K?

So, do you think something in the array is causing a hiccup on avrdude?

Ok, so here is what else I found out.
This issue only happens on the ATMEGA2560.
I loaded the code on a Duemilanove w/ optiboot and the code works just fine...
Weird...
I can't paste the code, but I attached this time.

the array in 24095 in size does not work

True, but that's not the point of the problem...
I just put DEC because I copied and pasted from the entire code I'm working on and although the array is in hex, for my application it is easier to know the value in DEC.
The array is actually a picture and the values I'm trying to read are the height and width of that picture.

Well, 24095 + whatever I have on the code doesn't go above the flash memory size.
Besides, I'm using Mega2560.
It runs just fine when I reduce the size of the PROGMEM array, but it doesn't run after a certain size, which I didn't try to find out yet.
So, yes... The code you posted works for me too.
Try increasing the size of the array.

Hi,

I'm having issues with PROGMEM.
Does a PROGMEM array have a limit in size?

Here is my code, which fails to execute and keeps rebooting my unit.
I had to shorten the array because it exceed the max length allowed per post.
The array is 24095 in size

Code:

#include <avr/pgmspace.h>


const prog_uchar logo[] PROGMEM = {
0xDA, 0x36, 0x05, 0x02, 0x0,
.
.
.
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

void setup()
{
  Serial.begin(57600);
  MemPrint(logo);
}

void loop()
{
}

void MemPrint(const prog_uchar *iPtr)
{
Serial.println(pgm_read_byte_near(iPtr),DEC);
}

Hi,

Once I change the board to Arduino Mega 2560 and connect a Duemilenove or Uno board to the computer, the upload process hangs and keeps timing out and never quits.
How can I stop the upload process without having to unplug the board or quit the avrdude process?

Thanks

Hi,

I get this error message that keeps going indefinitely everytime I choose Mega2560 board and a com port that is used by my FTDI cable.
I have to unplug the cable to get avrdude to stop trying to communicate.
Is there any way to have avrdude just give up trying to communicate after x amount of tries, just like it does with the 328 board?
I think it is related to the way STK500v1 and STRK500v2 is structured.
Anyone have any comments or ideas on how to get this resolved?

Thanks,
RI

Can I read/write to EEPROM with avrdude -U option?

Thanks. I was afraid that was the answer
I guess I'll have to come up with another solution for my problem then.

I know that would work for normal areas of flash.
But I think my problem is that I have lock bit 0x0f, which doesn't allow me to read from bootloader section.
Is that correct?