Script and Tests

Voltmeter Script

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

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.

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.