Comments on: Voltage Meter with Arduino Uno: Measure up to 30V https://peppe8o.com/voltage-meter-arduino-uno/ Raspberry PI, Arduino and Electronics made simple Mon, 03 Nov 2025 11:58:02 +0000 hourly 1 https://wordpress.org/?v=6.9.4 By: peppe8o https://peppe8o.com/voltage-meter-arduino-uno/#comment-71623 Mon, 03 Nov 2025 11:58:02 +0000 https://peppe8o.com/?p=7188#comment-71623 In reply to vik.

Hi Vik. In the best case, Arduino will read a 0V input (when the load has been inverted). There’s the possibility that the inverse polarity could stress the internal resistors of your microcontroller. The R1 resistor in the picture should offer you a basic protection from this, but adding a protection diode before the PINs should give you a safer design

]]> By: vik https://peppe8o.com/voltage-meter-arduino-uno/#comment-71557 Sun, 02 Nov 2025 15:13:43 +0000 https://peppe8o.com/?p=7188#comment-71557 What happens if you reverse the polarity?

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