Basics series: Button debouncing using interrupts

• Teensy 3.2
• What I thought was an average button

With the lockout time dropped down to 2ms I still couldn't get it to bounce so I'm happy with the testing. The code has to accept interrupts on both rising and falling edges so that it can sensibly distinguish between intentional state changes vs. bounces. The serial output below shows that a huge number of bounces occur for each succesfully interpreted button press.

Serial output:

1/1: Button pressed
2/11: Button pressed
3/17: Button pressed
4/89: Button pressed
5/91: Button pressed
6/94: Button pressed
7/100: Button pressed
8/102: Button pressed
9/121: Button pressed
10/131: Button pressed
11/139: Button pressed
12/141: Button pressed
13/157: Button pressed
14/201: Button pressed
15/213: Button pressed
16/216: Button pressed
17/227: Button pressed
18/237: Button pressed
19/245: Button pressed