48Vdc input

Hello, I want to measure 42 to 52vdc as an input and output it as a display bar type graph 0 to 100% using red, yellow to green LEDs.

Quite sure an Arduino can do this.

You have a question?

Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html

Can you tell us your electronics, programming, Arduino, hardware experience?

Thanks.. Tom.. :slight_smile:

The maximum voltage into the Arduino is 5V so use a [u]Voldage Divider[/u] (2 resistors) of, let's say, 11:1. And, if the voltage isn't somehow controlled/limited add a [u]protection diode[/u].

Start with the [u]Read Analog Voltage Example[/u] and adjust the scale factor to account for the voltage divider.

Add some LEDs and use [u]if-statements[/u] to turn-on the appropriate LED(s) depending on the voltage.

P.S.
Check the voltage out of the voltage divider with your multimeter before connecting the Arduino.

And, you may want to calibrate the Arduino's readings to match the multimeter (by adjusting the formula/scale factor). The ADC reference is the 5V power supply which isn't always "perfect"... Of course nothing is perfect.