The Constants reference page lists a few of the constants, but definitely not all of them. For examples, the constants DEFAULT, INTERNAL, and related others listed in analogReference's reference page.
There's also A0, A1, etc. which define analog pins - those aren't listed either, and aren't even mentioned in analogRead.
list the actual integer value of each constant. All constants of each group can be put in a table with one column for the name (e.g. LOW), one for the decimal value (e.g. 0)
Missing syntax reference - the ?: operator is not mentioned in the Reference.
I'm used to a wiki for reference
Those constants are very specific to that function and rarely used. The Arduino documentation focuses on being accessible to beginners which means not providing an overwhelming amount of information so I think it makes more sense to only mention the frequently used constants on that page. Maybe a note that it's not a complete list would make sense.
Now those are frequently used constants and it's surprising they aren't mentioned on either page.
The whole point of constants is that you don't need to know the value. I can't think of how that would be useful other than for people to use the information to write bad code that relies on those constants having specific values. This is a bad idea because there are many different platforms and some might use those constants in different ways.
The Arduino reference page is not intended to be a comprehensive C++ language reference. There are many of those already that do an excellent job of it. The Arduino reference page is mostly focused on documenting the API of the Arduino core libraries with a small amount of the most basic programming concepts thrown in. I do think it would make sense to add a note that many other C++ functions exist with a link to a full C++ reference. In fact it already does this for avr-libc but I don't think it's well explained and I don't think that's the best reference.
I'm somewhat in agreement but I also see that there are many people like you who don't fully understand the intention behind the reference page and would make it less beginner friendly.
A couple years ago they actually set up a system to make it very easy for anyone to submit proposals for changes to the pages but never made the final effort to actually use the thing, really sad.
However, You can submit corrections or suggestions for improvements here:https://github.com/arduino/Arduino/issuesI've found that if you take the time to clearly explain the issue and provided complete text for the suggested edit (rather than just a vague recommendation) they usually will take action very quickly. The person in charge of these edits, agdl, is very easy to work with. I have successfully gotten many problems fixed with the reference pages via that approach.
Corrections, suggestions, and new documentation should be posted to the Forum.
I should note that we do have a publicly editable wiki:http://playground.arduino.cc/and you are welcome to add any content you like there or make corrections or improvements to the existing content.
All reference pages say this at the bottom:If there's a better way, it should replace the forum link.
If you have found an error in the online documentation, please check if it's already known by looking at the github documentation issues, and if it's not known, please add it to the list.
I have an Uno and the constant A0 has the value 14. The example AnalogReadSerial uses this constant to read the value: int sensorValue = analogRead(A0);However, the analogRead reference page says: pin: the number of the analog input pin to read from (0 to 5 on most boards, 0 to 7 on the Mini and Nano, 0 to 15 on the Mega)So which is it? Is the reference page plain wrong, or are A0 and 0 equivalent for analogRead?
if (pin >= 14) pin -= 14; // allow for channel or pin numbers