AVR-Chat

You really DON'T need to think of "constants".

There are only two issues. 

1. Where is the value stored? It can be stored as part of a
table in program code and that is a real constant, for most
practical purposes unchangeable. It can be stored in SRAM.
In this case, it is highy changeable and goes away every
time power is turned off. It can be stored in EEPROM. It is
still changeable, but you don't want to do it really often.
And, it stays when the power goes off. The operations used
to read each is similar but slightly different.

2. What determines the value? A constant is determined at
the time that code is written. While it can be changed
later, it makes little sense in this kind of application.
All of the other kinds of data have to be determined some
other way; it might be by receiving data over the serial
port. It might by by reading a constant at startup and copy
to the memory location (ie, a "default" value). 

My point is that thinking about "constants" is not really
very useful or productive in this kind of application. A
number is a number.

Jim


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