# Arduino Wattmeter – Voltage, Current and Power Measurement

In this tutorial, I will tell you the best way to make an Arduino Wattmeter, a device that can be used to measure the power consumed by a load. With this project, this circuit can likewise go about as a Voltmeter and Ammeter to measure voltage and current.

Measuring voltage, current, and power is a fundamental assignment of any hardware engineer. For estimating voltage and current, we can use basic handheld multimeters as they give both the range and exactness for typical utilization. Yet, so as to measure the power, you have several choices from basic wattmeters to complex power analyzers and power meters.

Imagine a scenario in which I revealed to you that you can make your own Wattmeter with simple parts as a DIY project. Rather than purchasing a promptly accessible and costly Wattmeter, you can easily make your own Arduino Wattmeter. I will clarify all the essential advances required for the project.

There are various ways that you can actualize the Arduino Wattmeter Project. One of the simple ways is to interface a voltage sensor and a current sensor with Arduino, measure the voltage and current qualities, and lastly, with some arithmetic, you can compute the power in watts. In spite of the fact that utilizing sensors can give exact outcomes, where is the fun in utilizing sensors on the off chance that you can design the whole system yourself?

This is advantageous in the event that you are an understudy and attempting to get the hidden ideas. The strategy which I will actualize includes the total structure of the circuit.

For simplicity of comprehension, I will isolate the circuit into equal parts: Sensor Part and Control Part. The Sensor part of the circuit is answerable for estimating the voltage over the load and current through the load. Both these qualities, which are simple in nature, are given to the Arduino to its ADC. Arduino changes over these qualities to digital values and makes a couple of counts as presentations of the outcomes on the LCD.

## Components Required

• Arduino
• 16×2 LCD Display
• LM358 Op-Amp
• 7805 Voltage Regulator
• Resistors (1 Ω/3W, 1 KΩ, 2.2 KΩ, 10 KΩ, 20 KΩ)
• 10 KΩ Potentiometer
• Capacitors (100nF, 0.1µF)
• Push ON-OFF Button
• Connecting Wires
• 12V Power Supply

## PCB Design

For removing messy wiring and giving a clean look, I designed a PCB prototype for this project. It is also helpful for troubleshooting that runs great without any errors. To design this PCB board, I used EasyEDA as it is too easy to use. For ordering PCB for this, I personally prefer PCBWay.

Gerber file for Arduino Wattmeter Gerber File.

## Order PCB From PCBWay

This project is sponsored by PCBWay.com. PCBs are required everywhere in the electronics industry. So it needs to be good enough and have to serve the purpose for which they are needed without costing exorbitant amounts. PCBway offers all your needs come true. PCBWay is one of the largest PCB (Printed Circuit Board) manufacturing companies in china. It offers PCB prototype, PCB Assembly, SMD Stencil, and Flexible PCB.

They ship to more than 170 countries worldwide and process more than 2100 PCB orders a day. It feels like PCBWay gives an excellent price and customer service factor in one single serving. I personally ordered PCBs from PCBWay for my projects for just 5 dollars. I’ve used other PCB manufacturers too, but PCBWay has been offering the most reliable and consistent that I have tried. What is also spectacular about PCBWay to me, as a maker and customer, is their service. From their friendly support staff to their intuitive, user-friendly website features, it all counts towards what makes PCBWay an ideal company and brand for any electronics hobbyist.

Standard quality for any product needs to be maintained using some parameters. PCBWay gives that opportunity through quality control in designing and manufacturing. At first, they ensure the accuracy, clarity, and validity of the PCB files that we sent to them.

Then all the boards will go through the most stringent tests other than the basic visual check. They adopt most of the testing and inspecting equipment used in the industry, such as Flying Probe Testers, X-Ray Inspection Machines, and Automated Optical Inspection (AOI) machines. They are having 50+ new engineers on the daily basis around the world using PCBs for their work, who trust their reliable quality. They produce high-quality pink, orange, grey, and even transparent solder mask. Moreover, according to people’s needs, they can also provide Black core PCB. Check it out for a High-Quality PCB solder mask.

Then all the boards will go through the most stringent tests other than the basic visual check. They adopt most of the testing and inspecting equipment used in the industry, such as Flying Probe Testers, X-Ray Inspection Machines, and Automated Optical Inspection (AOI) machines. They are having 50+ new engineers on the daily basis around the world using PCBs for their work, who trust their reliable quality. They produce high-quality pink, orange, grey, and even transparent solder mask. Moreover, according to people’s needs, they can also provide Black core PCB. Check it out for a High-Quality PCB solder mask. There are some pictures below of the new colours of solder musks.

#### Features of PCBWay

PCB Prototyping & Manufacturing: PCBWay produces FR-4 and Aluminum boards and advanced PCBs like Rogers, HDI, and Flexible and Rigid-Flex boards, at a very reasonable price. Just check this Instant Quote to order premium PCBs for your hobby projects.

PCB Assembly: It not only offers PCB Prototyping but also offers PCB Assembly service. You can order a full PCB board with attached components by uploading your file. SMT & THT assembly starts from only 30\$ including free stencil and worldwide shipping. The components can be sourced and provided by PCBWay, or by the clients themselves.

Open Source Community: It not only offers PCB Prototype & Assembly services but also gives opportunities to students for sponsorships. I think this is so great. They feature their projects on the website also.

3D Printing & CNC: It also produces Rapid Prototyping like 3D printing, CNC Machining, Sheet Metal Fabrication, and Injection Molding. The quality of the product is too premium and reliable. And also the best part is that you will receive your order within a minimum of 3 days.

Services: PCBWay offers great servicing of its products. It takes only 3 to 15 days according to the courier service to deliver your products. Also, it has a live support facility. Whenever you have any problems, you can always reach a live customer service person to respond to your emails or messages. They have the “Return and Refund” principle, for every unusable board caused by PCBWay, they will rebuild and refund the order soon.

## Working Principle of Arduino Wattmeter

In the sensor part of the circuit, there are two sections that are responsible for measuring the voltage and current. For measuring the voltage, a voltage divider circuit is introduced to utilize a 10 KΩ and a 2.2 KΩ resistor.

Utilizing these resistors, you can measure voltages up to 24V. These resistors help us bring the voltage range from 0V to 5V, which is the range Arduino can work.

Presently, going to the current measurement, Arduino or any Microcontroller so far as that is concerned can just accept Analog voltage as input i.e. it can only read voltages. In the event, that Arduino can just understand voltages, at that point how can we measure current?

So as to measure current, you need to change over the current to a suitable voltage. Here comes ohm’s law to the salvage. According to Ohm’s Law, the voltage drop over a load is corresponding to the current. Thus, a little shunt resistor is put in for the load. By measuring the voltage over this resistor, we can measure the current.

The shunt resistor utilized here is 1Ω/3W. In any event, when the load draws a current of 1A, the voltage over the shunt resistor is just 0.2V.

This value is low for Arduino’s ADC circuit. Thus, I have utilized LM358 Op-Amp in a non-inverting amplifier mode to enhance the values given to the Arduino. The voltage divider network for the feedback control consists of a 20KΩ and 1 KΩ resistor. These resistors add to the addition of roughly 21.

The output of the amplifier is filtered and given to the Analog input pin of the Arduino. Arduino takes both the voltage and current values at Analog input pins A1 and A0 individually. Subsequent to performing a simple calculation, it shows the estimated value of the voltage, current, and power of the wattmeter on the LCD Display.

## Arduino Code

### 4 thoughts on “Arduino Wattmeter – Voltage, Current and Power Measurement”

1. Excellent Project

2. Nice

3. Good idea

4. Amazing power meter