https://www.baldengineer.com/tag/avr-gccRecent content in avr-gcc on Bald EngineerHugoen-USTue, 24 Mar 2015 22:13:55 +0000https://www.baldengineer.com/const-vs-define-when-do-you-them-and-why.htmlThu, 14 Nov 2013 11:13:40 +0000https://www.baldengineer.com/?p=1944<p>Arduino boards have microcontrollers with notoriously small amounts of RAM.  The Uno only has 2,048 bytes of static RAM available for your program to store variables.  So when you need to keep non-changing variables out of RAM which is best to use const or #define?</p> <h2 id="what-is-define">What is #define</h2> <p>#define is often misunderstood because it isn&rsquo;t a programming statement.  Instead, it sets up a macro which causes a text replace to occur before code is compiled.  For example in this code:</p>