Script and Tests

Voltmeter Script

  • Right-click measure_volts_with_cyberscope.hex (below) and select Save link as...

measure_volts_with_cyberscope.hex

  • If it's not already connected, connect your micro:bit module to your computer with its USB cable.
  • If you do not already have the micro:bit Python Editor open, browse to python.microbit.org in a Google Chrome or Microsoft Edge browser.
  • Click Open, select, and open measure_volts_with_cyberscope.hex.
    (See Save & Edit Scripts.)  
  • Click Send to micro:bit.
    (See Flash Scripts with Python Editor.)
  • Click the three vertical dots  ⋮  by the Send to micro:bit button, and select Disconnect.
    (See CYBERscope Voltmeter.)
  • Open a new browser tab and go to cyberscope.parallax.com.  
  • In the CYBERscope tab, click the Connect buttton.  
  • In the serial port dialog that appears, click the row with mbed in its name to select it, and then click Connect.

Voltmeter Tests

  • Use your probes to take the measurements shown in the animation.  The measurements are also listed step-by-step below the animation.

In these tests, you will measure voltages across the LED circuit’s components and compare them to the voltage across the +/- supply rails.

  • Use the animation and the instructions below it to measure voltage across the supply rails, then the resistor, then the LED.
  • Optionally, view the full-size kvl-measurements.mp4 clip to play and pause it between steps.

  • Check the voltage when the two probes are connected to the same row.  It should be very close to 0.00 V.
  • Measure the voltage across the (+) and (-) supply rails.
  • Measure the voltage across the resistor.
  • Measure the voltage across the LED.
  • Add the resistor and LED voltage measurements.
  • Compare it to the voltage across the (+) and (-) supply rails.