Measuring 20V alerts on an Arduino Uno with a quantizer – Open Electronics

By Marco Ventimiglia on July 26, 2022

As we all know, Arduino Uno features a 10-bit ADC (analog-to-digital converter) inside its ATmega328p, which takes a sign between 0 and 5V and produces a digital worth that varies from 0 to 1023. Nonetheless, making an attempt to measure any voltage above 5V will trigger some lower than fascinating outcomes, akin to creating magic smoke and destroying the microcontroller. To get round this, some makers add a voltage divider that divides the enter voltage by a predetermined issue. This answer reduces the decision of the ADC, as a single step of the digital worth corresponds to a higher voltage variation. To unravel this downside, the YouTuber referred to as Techoyaki has give you a brand new answer that may measure your entire vary of values ​​with out decreasing the decision.



The circuit divides the 0V-20V vary into 4 ranges (0V-5V, 5v-10V, 10V-15V and 15V-20V) translating all of them into the 0-5V vary. After that, these 4 obtained alerts arrive on the Arduino’s 4 analog inputs, which add up the values ​​to provide the equal of an ADC of practically 12 bits, thus resulting in values ​​that fall between 0 and 4092 (1023 x 4 ).

The circuit consists of 4 rail-to-rail operational amplifiers, and varied resistors, which permit to restrict the voltage obtained within the 0v-5v vary and subtract a DC voltage worth to impact the interpretation within the desired vary.

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