The Mega 2560 has SPI on pins 50, 51, and 52. The Ethershield only physically covers pins 0-13, A0 - A5, AREF, 3 GNDs, 5V, 3.3V, and RESET. Pins 14-53, 2 GNDs, 2 5V, and A6-A15 are exposed. I combined the Ethershield and Mega 2560 images to show this.


The 4th paragraph (line 1) of the Ethershield page indicates that it uses the SPI bus through the ICSP header. This would also explain why the Ethershield does not pass the ICSP header through. It is using it.

As for jumpering the pins that does not appear to be necessary. I have not seen any reference to that yet and the Ethershield is working fine at this time.

Sorry about that. I think everyone does it (and misses that point) because there is no physical connection to those pins (apparently, since it uses the ICSP header). When the Ethershield is covering the other pins it makes sense that some would be used. On a related note, all the tutorials mention ports 11-13 but nothing about the differences for the Mega. Ignorance is not an excuse though... and the tutorials have to be written with SOME basis of understanding.

Thanks again for the information. That of course solved it.

Running into an apparent conflict between the LiquidCrystal library and the Ethernet and UDP libraries. I get invalid characters and such on the LCD. Unfortunately this is entirely expected and completely my fault. So if anyone else hits this, follow the reply below. DO NOT USE pins 50, 51, or 52 except for SPI and do not use pin 53 if you are using the Ethershield.

I have this working fine on one computer, Windows 7 64bit where the associations have remained. On a separate computer, also Windows 7 but 32bit, the association was "lost" and has been unable to reset since. I can tell it to select the IDE but it will never actually open the file and never remains associated. On that computer I just open the IDE and open the file itself.

Not that this could be it, but it almost sounds like a power issue. I know you said the battery is good, but how many volts is the battery? The Mega 2560 has a little claim that if the power supply is less than 7 volts then the 5 volt pin may not provide 5 volts (which might be why the MIDI has no apparent power) and the board can become unstable.

I tried with a variety of strings including many that are longer (since I have many debug strings built in as I learn) but I have not tried other specialty characters. Something to check... I will come back with some results.

Edit - Tried with sets of the following characters and all succeeded:
` ~ @ # $ % ^ & * ( ) - _ = + [ { ] } | ; : ' , < . > / ?

Obviously using the following will not work (and yes I tried to prove it):
\ "
And the infamous !

Excellent, thanks for the input about the Uno. So as much as can reasonably be tested this is a Mega 2560 specific problem.

I created this thread in the Bugs & Suggestions category:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1294536128/0#0

I will edit it to add the point about you trying with Ubuntu and using 0021. I do not know if anything would result from it but it does not hurt to include all the details.

Does anyone reading this have an Uno they could try this out on? I am curious about whether it is a Mega 2560 problem or both of the new Arduinos being affected.

That was it?! I just tried it and sure enough it works just fine. I would say this is a definite bug for the 2560. Might be something in the bootloader. Fairly minor problem overall but who would think of it? I will check the problem lists to see if there is anything about this yet. If not I will submit it. Thanks very much for the help.

Ok. So no difference in OS (I am using Windows 7, 64bit also). I renamed all the variables and did a search on the site for any matches to those names (no hits for exact matches). Still failing.

I think if someone has a Mega 2560 to check this on it might be useful. I would not think it is a flaw with the bootloader... BUT I was in software QA and I still have that wonderful computer aura of what can go wrong around me at times.

Here is the latest "failing" code. Note: Problem is not commented at this time. If someone DOES have a Mega and has the problem, comment out the if statement for the IncrementingInteger == AlarmTriggerInteger and see if it still fails.

Code:

int IncrementingInteger = 1345;
int AlarmTriggerInteger = 1355;
boolean BooleanAlarmTriggered = false;

void setup() {
  Serial.begin( 9600 );
}

void loop() {
  delay( 5000 );
  IncrementingInteger = IncrementingInteger + 1;
  Serial.print( "Incrementing integer: " );
  Serial.println( IncrementingInteger );
  Serial.print( "Alarm trigger integer:" );
  Serial.println( AlarmTriggerInteger );
  if ( BooleanAlarmTriggered == false ) {
    if ( IncrementingInteger == AlarmTriggerInteger ) {
      BooleanAlarmTriggered = true;
      Serial.println( "Alarm has gone off!!!" );
    }
  }
}

I am using Arduino IDE 0022, so I already have the latest. I have my board selected correctly (Arduino Mega 2560) from the Tools - Board selection.

It is very odd. If I comment them everything uploads fine but with them uncommented it does not work. I tried adding the identifiers but that did not affect it at all. I wonder why it works differently on an Duemilanove (ie: it works). Are you using Windows or a different OS?

What is most frustrating is that without those lines it works fine. I have a whole webserver input/output sketch I have made that works fine and can be uploaded without trouble but I really want to have an alarm timer built in and this if statement is making that look doubtful.

I am currently running into a condition where my sketch will not complete uploading to my Arduino. The upload never seems to complete (even after 30min or so).

There are 4 commented lines in the attached code that appear to cause the problem. Removing the comments will cause the trouble readily. With those lines commented (and it appears to be the if specifically) the sketch uploads just fine.

Code:

int CurrentMin = 1345;
int Alarm1 = 1355;
boolean Alarm1Triggered = false;

void setup() {
  Serial.begin( 9600 );
}

void loop() {
  delay( 5000 );
  CurrentMin = CurrentMin + 1;
  Serial.println( CurrentMin );
  Serial.println( Alarm1 );
  if ( Alarm1Triggered == false ) {
//    if ( CurrentMin == Alarm1 ) {
//      Alarm1Triggered = true;
//      Serial.println( "Alarm has gone off!!!" );
//    }
  }
}

Please note that this sketch is just a sample to demonstrate the problem and is actually a very simplified subset of a bigger sketch. I am basically a beginner with the Arduino so maybe I missed something simple.

So can someone tell me what I am doing wrong?

Would you look at that! Apparently the search function on the issues site does not like "!!!" (which is how I checked if a bug already existed). It just lists all. But I did a search just now for Mega and found that existing one and mine. I will add a comment to mine indicating the prior bug. Now I REALLY feel redundant.

Having spaces between the exclamation marks works just fine. I just removed the extra exclamation marks since it was just a happy debug note that I got the alarm working.

It has to be my original background in Software QA coming to haunt me like normal...

Case in point, I often use POV-Ray for some other work and have found 2 bugs there that were unknown because nobody used it in ways I did (debug file data getting overwritten instead of appended and failure rendering images 41000x41000 pixels). Go figure.

I saw the mention about the Google Code issues section (oops) and have now posted this there with all the information everyone has helped me get (and links to the posts). It is issue 459.
http://code.google.com/p/arduino/issues/detail?id=459