lecture:lecture_12
Lecture 12: Design of Support Structure for the Desktop Fan; Button Input
Checklist: What you need to bring for this lecture
- Laptop
- Sparkfun Tinker Kit or Sparkfun Inventor's kit
- Digital multimeter
- Miniature test clip adapters
Learning Objectives
After this lecture you should be able to
- use a while loop in Arduino code
- explain the behavior of pull-down and pull-up circuits for buttons
- explain how normally open (NO) and normally closed (NC) switches (or buttons) function in a DC circuit
- create a circuit for using a momentary button as a digital input
- use a momentary button as a “wait-to-start” input
Reading
- Notes on while loops (PDF, 6 pages)
- Notes on using momentary buttons (PDF, 11 pages)
Videos and Lecture Slides
Button input for Arduino
Arduino Codes
Each of the following codes are designed to handle the input from a momentary button configured with a pull-down resistor.
- button_status.ino is a simple sketch to indicate whether the button is currently pressed. Apart from displaying the button status, this program has little practical use.
- button_wait_for_input.ino is a sketch that blocks execution until a button is pressed. This could code could be used as a wait-to-start button.
- button_interrupt.ino demonstrates how to use an interrupt to detect when a button is pressed. This is the recommended strategy for using button input.
- button_interrupt_count.ino is the same as button_interrupt.ino except that the total number of button presses since start-up is printed to the Serial Monitor.
lecture/lecture_12.txt · Last modified: 2020/01/08 14:55 by johnj