Review and Practice

Self-check

In this activity, you used a voltmeter to measure the voltage supplied by the I/O pins to turn the LED on and off in the P13 LED light circuit.

  • Were you able to slow down the blink to take the measurements with the voltmeter?
  • Do you understand why there is a change in the voltage when using different size resistors?

 

Questions

  1. How many volts is the supply voltage for your micro:bit circuit?
  2. Why is the measured voltage across the circuit closer to 2.65 V than 3.3 V?
  3. What is it called when you disconnect the circuit load from the supply?
  4. What happens to the voltage through the circuit when you put in a bigger resistor?
     

Exercises

  1. What line allows the script to access voltage measuring functions and display with the CYBERscope?
  2. The voltmeter() function is used to measure what?
  3. What allows the voltmeter to measure both the high and low signals?


 

Project

Use the voltmeter to check the voltage across the yellow LED circuit. Confirm that it is similar to that of the green LED circuit.