5th Information Technology for Education and Development (ITED) 978-1-6654-9370-3/22/$31.00 ©2022 IEEE Design and Implementation of a GSM and Wi-Fi Based Low Cost Smart Prepaid Energy Meter Henry E. Amhenrior Department of Electrical/Electronic Engineering Edo State University Uzairue Uzairue, Nigeria. henrino2003@yahoo.com I. Oloma Hardweb Solutions Pedro Somolu Nigeria. adroicselectronics@gmail.com Braimoh A. Ikharo Department of Electrical/Electronic Engineering Edo State University Uzairue Uzairue, Nigeria. braimikharo@gmail.com Abstract - This paper presents a GSM and Wi-Fi based Low Cost Single phase Smart Prepaid Energy Meter with some functionalities such as keypad and screen implemented in embedded software. The design was borne out of the desire to ensure that smart prepaid meters are made available at a reduced cost. The methodology involves hardware and software. The hardware made use of integrated circuits (ICs) and discrete components. At the heart of the design is Atmega644P microcontroller which was interfaced to ADE7755 energy meter IC, GSM800L modem, Wi-Fi module, tamper switch, buzzer and other components. The microcontroller is used for monitoring and controlling the activities of the meter especially the ADE7755 used in producing pulses from consumption which are then measured and recorded by the microcontroller as Energy measurement. SIM800L was used to achieve communication between the meter and the web server. The Wi-Fi is used to access the meter for recharging. The software aspect involved the programming of the microcontroller using C++ and the use of a webpage with an associated web server for meter administration and control as well as meter token recharge validation. The prototype performed satisfactorily under different loads. Other functionalities such as tampering detection, token recharge, meter registration and meter information viewing on the webpage were successfully executed. Again, the cost of the meter is less than the cost of commercially available meters in Nigeria by ₦18,313.39. The GSM and Wi-Fi low cost smart energy meter designed and implemented worked satisfactorily and it is effective. Indexed Terms- Embedded Software, Energy measurement, GSM, Integrated Circuit, Web servers, Wi-Fi. I. INTRODUCTION The craving for smart electric energy meter is on the rise in most parts of the world and particularly in Nigeria. This is because of its several benefits to both the electricity consumers and the Electricity Supply Authority (ESA). One of such benefits is the comfort in the use of energy meters which is an important factor in the choice of electric energy meter by consumers. For example, in Nigeria, consumers with smart prepaid energy meter are not harassed by ESA personnel during bill collection as they pay their electricity bill before consumption. They recharge their meters at will and they are able to control their consumption of energy to suit their budget. This development is also advantageous to the ESA as they do not deploy personnel and financial resources for bill collection on monthly basis in the use of smart energy meters. As the demand of smart meters are rising, the cost of obtaining these meters are equally rising. For example, in Nigeria the average cost of single-phase and three-phase meters are ₦49,063.39 and ₦89,157.81 respectively. This cost is high compare to the per capita income and the national minimum wage of ₦18,000 of the citizens. Hence, there is a need to design and develop a smart prepaid electric energy meter that should reflect the financial status of the citizens. II. LITERATURE The use of electricity spread rapidly in the 19 th century and this saw the patenting of the first lamp-hour meter in 1872 by Samual Gardiner. It was a DC meter that was also a clock. It used an electromagnet to start and stop its operation [15]. Since that time, energy meter has seen evolution through many changes and improvements. Several researches have been carried out on various areas of metering technology to improve it. One of the earliest attempts at bringing efficiency and smartness into the analog and electronic meters was the introduction of Automatic Meter Reading (AMR). In line with this, [14] proposed what they called the Voltage Ampere Power Smart Meter (VAPSM) which main controlling unit is the microcontroller. The meter was an AMR system as it is aimed at aiding billing information collection from the users to the ESA. Many researchers have over the years design and developed various smart meters using different technologies. Reference [12] used Arduino MKR1000 microcontroller board at two levels of functionalities. Firstly, it was used to control the workings of the meter and secondly, it was interface with the Wi-Fi network through which the internet is accessed. It also used an Infrared Sensor to monitor tampering by opening of the meter, and a Solid State Relay to interface the loads to the electricity distribution network. The work is based on the use of Thingspeak.com Internet of Things (IoT) platform for analyzing and visualization of the meter status by the ESA. This system is primarily a theft detention system using IoT technology. Also, [2] designed an IoT smart energy meter using Arduino UNO as the Microcontroller. The controller was interfaced with an LCD, a Triac for theft detection, and sensors for gas, temperature, fire etc. and also, a Wi-Fi module for communication in the transmission of meter readings to the internet where consumption could be monitored. This design seems to be an additional device interfaced to an already existing meter used in taking readings from the existing meter and sending the data to a web page for the purpose of monitoring consumption and as such, it is not a true design of a meter rather an aid to meter reading. References [16] and [18] proposed a system similar to that of reference [2] except with the inclusion of recharging functionality on the web page and the use of GSM modem as the communication link that is used for meter reading and data transfer to the ESA. Reference [8] proposed the design of a single phase prepaid meter that is based on PIC16F84A microcontroller with a Visual Basic 6.0 software graphical interface to enable the system to be managed in a computer. Reference [9] designed an