Review and Practice

Self-check

• In this activity, you:
  • Measured continuity between various combinations of the pushbutton’s pins while it was pressed and not pressed.
  • Looked inside the pushbutton to see how pressing it made the electrical connections change.
  • Examined the functions of the resistors in the pushbutton circuit.
• Do you understand the continuity inside the pushbutton?
• Do you understand how the pull-down and pull-up resistors work inside the pushbutton circuits?
• Were you able to successfully use methods specific to the pushbuttons scripts to manipulate the pushbuttons and LEDs

Questions

1. Which pushbutton pins are always connected to each other?
2. When the pushbutton is pressed, what is the voltage through the circuit and why?
3. What function does a pull down resistor have in a circuit?
4. Describe “active-high.”
5. When a pushbutton doesn’t work as expected, what is one of the first things that professionals check?

Exercises

1. In simple terms how would you describe a schematic of a pull-down resistor circuit versus a pull-up resistor circuit?
2. How does display.off() impact pin 6?
3. How does pin6.set_pull(pin6.NO_PULL) work within a pushbutton circuit connected to P6?
    

Project

Imagine that you want a light to blink red when nothing is sensed but to stop when an object is present, much like an automatic door opens when you step on a mat, but is closed the rest of the time. Write a script so that your new pushbutton pull-up circuit flashes the red LED without a pushbutton press and turns off when you press the pushbutton.