hey guys ..so im new to arduino so i have lods of doubts so one of them is that ..
can i use analogue pin to read as digitalread
say for example;
digitalRead(A0)
does this statement make any difference in the program??
Yes, you can.
can i use analogue pin to read as digitalread
say for example;
digitalRead(A0)
Yes.
does this statement make any difference in the program??
I don't understand your question. I feel like saying "yes, it will make the program one line longer".
When in doubt, RTFM
AWOL:
When in doubt, RTFM
The Reference Manual insists to put pin number in the argument of the instruction digitalRead(pin). So, which one of the following two is an appropriate one although both are accepted by the compiler.
digitalRead(A0);
digitalRead(14);
So, which one of the following two is an appropriate one although both are accepted by the compiler.
Either is acceptable, but it is sensible to use the pin numbers/names as printed on the board because doing so avoids problems in running code on different boards where A0 is not pin 14, for example.
Delta_G:
Those two lines are identical.
As already pointed out by UKHeliBob this is true (for example) for the UNO but not for other boards like the Leonardo (where A0 = 18).
So it is always recommended to use pin numbers / names as printed on the board.
UKHeliBob:
Either is acceptable, but it is sensible to use the pin numbers/names as printed on the board because doing so avoids problems in running code on different boards where A0 is not pin 14, for example.
There can be issues with some 3rd party boards & shields as some have Dn printed on their digital pins.
Like the Iteaduino boards.
The issues is that the pins are labeled as "D0, D1, D2 etc..."
So while the variant files for the official boards, which come with the IDE (which these clones use) define the An symbols (A0, A1, A2 etc...) the official boards do not define Dn symbols.
So on some 3rd party clones you can't actually use what is printed on the board for the digital pins.
i.e. it has D2 printed on the board but you must use 2 instead.
All that said, the reverse can also be true for some boards.
For example, there can be issues with pins on the esp8266 Wemos boards.
Those boards label their pins as Dn and also include Dn symbols in their variant file.
In fact on those boards you must use the Dn symbol names if you want to access the correct pin since
Dn is not the same as pin n.
i.e. D9 is not the same pin as 9
This is because naked constants in the esp8266 core are esp8266 GPIO bit numbers while the Dn symbols are mapped to GPIO bit numbers and Dn symbols are not directly mapped to GPIO bit n.
On the esp8266, only the wemos boards do this and have the Dn symbols so it isn't a esp8266 core thing.
It is specific to the wemos boards.
So:
An works everywhere and should be used to access the "analog pins".
Most boards label their digital pins as n and n is used to reference it.
Some boards label their digital pins as Dn but must be referenced as n
Some boards label their digital pins as Dn and must be referenced as Dn
--- bill