The  IoT  allows  objects  to  be  sensed  or  controlled  remotely  across existing  network  infrastructure,  creating  opportunities  for  more  direct  integration  of  the  physical  world  into  computer based systems and resulting in improved efficiency, accuracy and economic benefit in addition to reduced human intervention. This project controls the DC motor speed and direction using internet of things. Internet is the most widely used high speed andeasily accessible communication medium in the modern day world. The proposed system is simple and highly effective in terms of cost and efficiency. In this system, the direction and the speed of the DC motor can be controlled by internet over a remote location. It uses Wi Fi controller ESP 8266 to connect the project with internet. At the same time speed of D.C. motor is measured by infrared sensors placed near shaft of motor. The speed measured by infrared sensor and PIC microcontroller will be displayed on LCD display. The PROTEUS simulation confirmed the theoretical estimates of the performance of the proposed system.

The underground cable system is a common practice followed in many urban areas. While a fault occurs for some reason, at that time the repairing process related to that particular cable is difficult due to not knowing the exact location of the cable fault.

The objective of this project is to determine the distance of underground cable fault from base station in kilometers. When a low DC voltage is applied at the feeder end through a series resistor (Cable lines), then current would vary depending upon the location of fault in the cable. In case there is a short circuit (Line to Ground), the voltage across series resistors changes accordingly, which is then fed to an ADC to develop precise digital data which the programmed micro controller of AVR family would display in kilometers.

The project is assembled with a set of resistors representing cable length in KM’s and fault creation is made by a set of switches at every known KM to cross check the accuracy of the same. The fault occurring at a particular distance and the respective phase is displayed on a LCD interfaced to the micro controller.

Keywords: - AVR controller, fault detection, fault location, underground cable

Tachometer is device used to count the revolutions per minute of a rotating shaft. Generally tachometer makes direct contact with the rotating shaft. It will reduce the velocity of the shaft, giving faulty readings. Hence it is needed to measure the speed of rotating shaft without direct contact.

This project describes a contact -less tachometer using AVR microcontroller ATmega328P and a hall affect sensor. This device can very accurately measure the rotational speed of a shaft without even touching it.

This device is built on an ATmega328P microcontroller, an alpha-numeric LCD module and a Hall Effect sensor to detect the rotation of the shaft whose speed is being measured.

In this project Hall Effect sensor acts as a digital counting device. It will detect any magnetic element passing in front of it and thus, will give an output pulse for each and every rotation of the shaft. These pulses are fed to microcontroller. Microcontroller counts the pulses coming from Hall Effect sensor.

The speed of BLDC motor will be displayed on LCD module as well as on android application through Wi-Fi. The android application can perform the switching and speed varying operation of BLDC motor through remote location through Wi-Fi.

Keywords- AVR microcontroller, alpha-numeric LCD module, Hall Effect sensor, Wi-Fi Controller

Auto supply switching is basically selection of supply from multiple available power sources automatically by using microcontroller concept that is to check the availability of the source and switching to that available source to ensure uninterrupted power supply to load. In case of the electrical appliance control using automation causes more safety.

Auto supply switching is a prototype for the same which is auto change to other source when main supply fails without human interaction in this system we are designing an embedded circuit to control and ensure auto supply switching. In case all 4 phases are available, then the switching will be in the default phase. Four relays are there to control the switching. As it is not feasible to provide all 4 different sources of supply, one source with alternate switches are provided to get the same function.

In this project 4 switches acts as 4 different source of supply. When any switch is pressed it shows the absence of that particular source which is connected to microcontroller as input signals. Here we are using ATmega328P microcontroller.

The output of ATmega328P Microcontroller is given to the 4 relays JQC3FC, which switches appropriate relay to maintain an uninterrupted supply to the load. The output can be observed by Bulb/Lamp. The switches can be switch ON and OFF by Wi Fi controller ESP8266. Due to this load can be operated at remote location through internet. On failure of the supply from first switch the load gets supply from the next available switch. If the supply from second switch also fails it switches over to the next available source and so on.

Keywords: - Atmel AVR family, auto switching, Wi Fi module