Arduino Voltmeter

Arduino Voltmeter - techprolet_ wiki

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Arduino Voltmeter Voltmeter From techprolet_ wiki Arduino boards boards are equipped equipped with analog inputs. Using the input voltage as 5V reference, one can read the analog input of any given 0-5V voltage with an accuracy of 5V/1024 = 4.88 mV (hint: don't expect accuracy to be anywhere near that number). Arduino in in fact can take take differents differents input as its its voltage reference reference [1]. In our example, we use USB as our power source and make the assumption that reference input voltage is a constant 5V.

Example implementation What follows is a simple voltmeter used to monitor a 7.4V LiPo 2S battery pack. The charge balancer connector of a 2S (2 cell) LiPo has 3 terminals (black - GRND, blue - end of first cell, red - end of second cell). We measure the voltage difference between GRND and the second cell, which has a nominal voltage 7.4V. Breadboard schematic of the simple voltmeter example

Since the analog input maxes out at 5V, we use 2 2.2kΩ resistors in series as a voltage divider. This means that when the battery pack is connected to the voltmeter, at least 7.4V/4.4kΩ = 1.7mA or (7.4^2)/4400=12.5mW are consumed. The battery's GRND is connected to Arduino's GRND and the point between the two resistors (where the voltage is halved) is connected to Arduinos Analog Input Input 0.

Simple voltmeter breadboard



Arduino Code:

/* Simple Voltmeter Copyright 2013 Pavlos Iliopoulos, te This program is free software: you c it under the terms of the GNU Genera the Free Software Foundation, either (at your option) any later version. This program is distributed in the h but WITHOUT ANY WARRANTY; without ev MERCHANTABILITY or FITNESS FOR A PAR GNU General Public License for more

Serial output of the simple voltmeter arduino sketch

You should have received a copy of t along with this program. If not, se */ //set reference voltage; float refVcc = 5.0;

// the setup routine runs once when you void setup() { // initialize serial communication at Serial.begin(9600); } // the loop routine runs over and over a void loop() { // read the input on analog pin 0: int sensorValue = analogRead(A0); // print out the value you read: Serial.print("Analog read: "); Serial.println(sensorValue); // print out the converted (voltage) v Serial.print ("Voltage: "); Serial.print (sensorValue*refVcc/1024) Serial.println ("V"); Serial.println("--------------------") delay(1000); // delay a whole s }

The Quadcopter Battery Monitor builds on the logic described here.



References 1. ↑ arduino analogReference [1] (http://arduino.cc/en/Reference/AnalogReference) Retrieved from "http://wiki.techprolet.com/index.php?title=Arduino_Voltmeter& oldid=43" Categories: Arduino Batteries DC Power Quadcopter This page was last modified on 24 February 2013, at 16:29. This page has been accessed 38 times.

Arduino Voltmeter

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