I just downloaded the latest version of the Arduino software (1.6.5). However, when I look into the Application Support folder under Library (I have a mac), I find that I have a folder named 1.6.3:

Library ▸ Arduino15 ▸ packages ▸ arduino ▸ hardware ▸ sam ▸ 1.6.3

Does this mean there is a hidden 1.6.5 folder that I am not seeing?

BTW, this issue surfaced, because I am trying to fiddle around with the ADC clock speed, but it seems that nothing is happening:

void setup() {
  #define ADC_FREQ_MAX = 1;

void loop() {

gives me:

opamp.ino: In function 'void setup()':
opamp:2: error: expected primary-expression before '=' token
opamp.ino:4:18: note: in expansion of macro 'ADC_FREQ_MAX'
opamp:4: error: expected primary-expression before ')' token
opamp:4: error: expected ';' before ')' token
expected primary-expression before '=' token

closed as unclear what you're asking by sa_leinad, Enric Blanco, Chris Stratton, Greenonline, Code Gorilla Jul 7 '17 at 9:01

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • It could simply be that the versions of code within that folder are at a level called 1.6.3. Big applications are usually componentized which means that the release level of the app as a whole may be different from the release levels of its parts. I could easily imagine that inside the 1.6.5 IDE there are parts that haven't changed since 1.6.3 and hence retain that version identity. – Kolban Jun 19 '15 at 0:42
  • Ok, but I am changing the ADC frequency to like 1Hz, and I can't see any noticeable change, i.e. the analogRead() function still samples way faster than that - an apparent contradiction (I've even restarted the IDE) – David Roberts Jun 19 '15 at 0:43
  • 1
    Your define is incorrect, it should be #define ADC_FREQ_MAX 1 only, no =, no ;. – jfpoilpret Jun 19 '15 at 4:38
  • It's likely the different versions have been installed in different places - system wide vs. user-specific, etc. – Chris Stratton Jul 6 '17 at 19:03
  • I'm voting to close this question because there isn't a single, specific clearly answerable question here, and the question has been abandoned in this state long enough that it is unlikely to ever be improved. – Chris Stratton Jul 6 '17 at 19:04

1.6.5 is the version of the Arduino IDE.

1.6.3 is the version of the Arduino SAM Boards package that you have installed.

Does this mean there is a hidden 1.6.5 folder that I am not seeing?

Library/Arduino15 is where your preferences.txt file and Boards Manager index files are stored. Library/Arduino15/packages is where hardware packages installed via Tools > Board > Boards Manager are stored. The Arduino IDE will be located elsewhere on your hard drive. If you need to find it here is an easy way:

  1. Tools > Examples > 01.Basics > BareMinimum
  2. Sketch > Show Sketch Folder - this will open the Examples/01.Basics/BareMinimum subfolder of the Arduino IDE installation folder.

BTW, this issue surfaced...

That's off the topic of your question and already answered in a comment on your question so I will refrain from answering it.


The error you see is because of the equal sign in your #define. That equal should not be there. So the line that uses it ends up being.

Serial.println(= 1);

Which is obviously wrong.

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