In the Arduino library, the Serial object has a method called “flush().” Often users go throwing it into programs without fully understanding what it does. It doesn’t help that it’s functionality changed when version 1.0 of the Arduino IDE was released.
Does Serial.flush() affect the Transmit Buffer or the Receive Buffer and when do you need to use it?
The Arduino is fast, humans are slow. When you push down a button, what seems like a single change to slow humans is really multiple presses to an Arduino. This is known as “bouncing.” Figure 1 is an oscilloscope screenshot showing what could happen when a button is pressed.
You’ve recently learned about millis() and can’t way to delete all of your references to delay(). The problem is that you don’t know quite how to convert your code into millis()-compatible code. Here is a (running) list of millis() examples I’ve put together to help.
You might also want to check out my “Blink Without Delay – Line by Line Tutorial.” It is a much more in-depth explanation than the comments provided with the Arduino IDE example.
It’s 3am but you are not going to bed until you squash this last bug. You sprinkle Serial.print() statements everywhere you can think of, and then that’s when all hell breaks loose: Your code randomly locks up, the LEDs go crazy, and you’ve had it. What’s going on? You’ve run out of RAM!
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?
