A new category of click boards™ is emerging, defined by the word “meter” in their name. The latest entry is Voltmeter click, from the same designer who brought you C Meter, R Meter and Ammeter in the last few months.
The first Voltmeter was invented by Andre-Marie Ampere, while the last Voltmeter (at time this post was published) was invented by an engineer named Mirko Grba, who also made Ammeter click that measures Andre’s Amperes.
Voltmeter click has a self-explanatory name. We should only add that it’s strictly for measuring Direct Current, within a 0-24V range (both positive and negative charges).
As with previous something something meter clicks (excluding RF Meter), this one also has several components that do the work (instead of a single chip that carries the whole functionality). A voltage – proportional to the input charge – is generated across the last two resistors. From there it is sent to the differential amplifier that further intensifies the difference between the two inputs (+/-).
The resulting values are passed through a 12-bit ADC and are exactly 33 times lower then the exact voltage, but your target MCU can do the simple math to get you the exact voltage.
And as a reminder, here are the previous meter clicks: