Voltmeter

The 2 line LCD display controlled by a HD44780 LCD controller can be used for a number of small projects. Here we use it to display the voltage drop over a potentiometer. This voltage is converted to digital by a PCF8591 8 bit Analogue to Digital Converter (ADC) which gives us an 8 bit value. The max. 8 bit number corresponds to the supply voltage to the ADC, the lowest is zero. Taking this into account we can convert this digital value into Volts and display the result on the 2-line display.

We have just built a simple Voltmeter whose working can be seen when changing the resistive value of the potentiometer by turning it left or right.

-- Uli Raich - 2017-10-06

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