How to Measure Ampere using ACS712 current Sensor with Arduino

 How to Measure Ampere using  ACS712 current Sensor with Arduino

Have you ever stopped and wonder the amount of current each of your electrical appliances require? Well, it’s a tedious process to know it all but that’s where the functionality of a current sensor comes to play. With different devices having different current requirements, if a wrong amount of current is fed to them, it may result in severe circumstances (overloading, etc.). Hence, it’s necessary for one to monitor the required current for applications, and that’s when people turn to a current sensor to do the job, notably the ACS712 AC/DC Current sensor.

What is the ACS712 AC/DC Current Sensor?

The ACS712 is a fully integrated, hall effect-based linear current sensor with 2.1kVRMS voltage isolation and a integrated low-resistance current conductor. Technical terms aside, it’s simply put forth as a current sensor that uses its conductor to calculate and measure the amount of current applied.

The features of ACS712 include:

• 80kHz bandwith
• 66 to 185 mV/A output sensitivity
• Low-noise analog signal path
• Device bandwith is set via the new FILTER pin
• 1.2 mΩ internal conductor resistance
• Total output error of 1.5% at TA = 25°C
• Stable output offset voltage.
• Near zero magnetic hysteresis

For more information on ACS712 pinout, schematics, and circuit diagram, you can download ACS712 datasheet here!

How does the ACS712 Current Sensor work?

Now that we’ve had an idea of what the ACS712 is capable of, we’ll take a look at its working principle. Well, when it comes to how a current sensor works, it can either be done through direct or indirect sensing. For the ACS712, it uses indirect sensing.

• For current sensors that work by direct sensing, ohm’s law is being applied to measure the drop in voltage when flowing current is detected.

Here’s how the ACS712 work (Simplified):

• Current flows through the onboard hall sensor circuit in its IC
• The hall effect sensor detects the incoming current through its magnetic field generation
• Once detected, the hall effect sensor generates a voltage proportional to its magnetic field that’s then used to measure the amount of current

ACS712 Current Sensor Applications

We’ve established a general idea of what current sensors are applicable for earlier. Well, with the ACS712 IC being able to detect both AC/DC current, it can be used in a wider range of applications apart from electrical appliances. Be it Arduino/other microcontroller usages, or industrial, commercial, and communication applications, it can be found applicable.

Here are the common list of applications:

• Motor speed control in motor control circuits
• Electrical load detection and management
• Switched-mode power supplies (SMPS)
• Protection for over-current

ACS712 Current Sensor Arduino Guide

The ACS712 current sensor can be connected to your Arduino board through a series of jumper wires connections based on its pinout. However, here at Seeed, we understand the complications and complexity of doing so. Hence, we’ve decided to provide a tutorial for our Grove – ±5A DC/AC Current Sensor (ACS70331) to display how easy our Grove plug-and-play system is!

Here’s what you need for today’s tutorial:

 

Download Library

Code Below

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#include "ACS712.h"

/*

  This example shows how to measure DC current

*/

// We have 30 amps version sensor connected to A1 pin of arduino

// Replace with your version if necessary

ACS712 sensor(ACS712_30A, A1);

void setup() {

  Serial.begin(9600);

  // This method calibrates zero point of sensor,

  // It is not necessary, but may positively affect the accuracy

  // Ensure that no current flows through the sensor at this moment

  sensor.calibrate();

}

void loop() {

  // Get current from sensor

  float  I = sensor.getCurrentDC();

  Serial.println(String("I = ") + I+ " A");

  

  // Wait one second before the new cycle

  delay(100);

}

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