Wireless communication can be defined as transfer of information between two or more points without using wires or cables. There are different wireless technologies such as RFID, IR, GPS, Bluetooth, and WI-FI, etc. In olden days location announcement was done with the help of speakers, but now it is developed by using IVRS in railways stations. Nowadays bus location can be found with the help of Geo Positioning satellites.
This bus location announcement system is very helpful for people who are illiterates and new to cities. This system can be applied in different areas like transport companies, public trains, private travels, government travel agencies, service organizations, etc.
GPS Involvement in Finding Bus Location
Global positioning system is a satellite-based navigation system used to locate positions anywhere on earth. This kind of technology can be used in various areas like military, commercial usage and civil services all over the world. GPS can be used for these purposes: trilateration, perfect timing, positioning of satellites and error connection. Here is the general example describing the use of GPS:
To locate the distance between two places and to know the far away distance from another location, GPS is used for exact location such as (latitude, longitude and height) on the earth within the range of 20m to 1mm.
Most of the citizens prefer buses for a long-distance journey to avoid accidents. When a bus reaches a station, it’s a big problem for many passengers to know the destination. To overcome this problem, a bus location announcement system is the best option as it informs us about the bus location by using GPS technology. Such a system which uses GPS technology is being practically explained in the subsequent paragraphs.
GPS receiver concept is based on the position and timing signals send by the satellites, and the information can be transmitted in such a way that a message is transmitted at certain time and position of the satellite during message transmission.
The GPS system consists of three segments: space segment, control segment and user segment. Space and control segments are operated, developed and maintained by U.S air force; user segment includes both military and civilian users and their GPS equipment.
Space Segment: It comprises 24 satellites from which 21 are navigational space vehicles and 3 are active spares orbiting at an altitude of 11000 nautical miles. These satellites are stable and predictable due to their high altitude. This system consists of six orbital planes that are equally placed at 60 degrees and inclined at about 55 degrees on equatorial plane.
Control Segment: This segment comprises a master control station, an alternate motor-control station, four ground antennas and six monitor stations. These monitor stations are placed all over the world, to measure the signal from space vehicles which are incorporated into an orbital model of each satellite. Dedicated antennas are used for broadcasting the signals to satellites.
User Segment: This system consists of receivers which can be handheld or installed on aircraft, ship, submarines, cars and trucks. Receivers can decode, detect and process the signals to satellites. These signals can be changed into velocity, position and time. This segment can be used in different applications such as military, shipping, surveying, satellite positioning and tracking.
GPS can be used in different applications such as military and civilian applications. Civilian field utilizes one or more GPS basic components that are used for absolute location, relative movement and transfer of time.
- Automated Vehicle: This application is used for locating cars and trucks that function without requiring help from human beings.
- Geo fencing: Vehicle tracking system, person tracking system and pet tracking system – all these systems make use of GPS to track vehicles, person or pets. This application provides continuous updates of locations through mobile and internet.
- GPS can be used for the measurement of faults during earth quakes.
- GPS can be used in the field of robotics mainly for military robots in real-time applications.
This is all about the GPS technology in detail, and to make this concept more pragmatic, the following practical example as a project to locate a bus is very practical.
GPS based Bus Arrival Announcement System for Buses and Trains
The project is designed to locate a bus and announce the location with the help of GPS technology, by using which the signals sent by the satellites to a GPS receiver are interfaced with a PC for locating the exact location of the bus.
GPS receivers are used to provide three-dimensional locations such as latitude, longitude, and altitude with precise time. These receivers provide reliable positioning, navigational and timing services to worldwide users in any climatic conditions whether day or night anywhere in the world and around the earth.
Block Diagram Description
The block diagram consists of the following seven sections:
This Microcontroller is the most important segment of this project as it controls all the operations of the circuit such as reading data from the GPS modem which is connected serially with a Personal Computer interfacing.
Most of the projects make use of displays for displaying information. There are various displays used in those projects such as seven-segment displays and 5*7 displays. Selection of display depends on the following factors like power consumption, ambient lighting conditions and cost of displays.
This project utilizes MAX 232 for interfacing the system with a GPS module and computer. The locations generated by the GPS module are sent to the computer serially with the help of MAX 232. The MAX 232 converts RS 232 signals to TTL voltage levels and thus makes use of +5v power source, which is same as the source voltage from the 8051 microcontroller.
This block contains step-down transformer, a bridge rectifier, a filter capacitor and a voltage regulator. Single-phase AC power supply from the mains is step down to a lower voltage which is again rectified to DC using bridge rectifier. This rectified DC is filtered and regulated to a circuit operating range with a capacitor and regulator IC, respectively.
The GPS module operates at 9600 or 4800 baud rates. It continuously receives coordinates from three orbiting satellites. This GPS modem is used to get the current location of a vehicle.
This speaker is a single chip voice recording speaker that plays back solution interfaced with microcontroller and announces the data with the help of a speaker.
Circuit Operation of Bus Arrival Announcement System
This project consists of an 8051 microcontroller, a GPS Modem and a LCD Display. This entire circuit is placed inside a bus or train. The power supply provides the voltage to entire circuit. The GPS modem consists of a receiver that receives the signals from the satellites based on latitude, longitude and altitude. These coordinate values are stored in the microcontroller. These coordinates represent the bus or train locations. These coordinates’ values are compared with the values from the GPS receiver.
These coordinated values are equal to the latest coordinates coming from the GPS modem and are converted into TTL level with the help of MAX 232. If the latest values match with the stored coordinates values in the microcontroller, it displays the location name on the LCD display, and then announces the stop name by using the Speaker IC. This project is helpful for the people who are new to a city.
This is all about the GPS technology and microcontroller-based project for bus location announcement system that uses GPS technology. We Hope that you have got a better understanding of this overall topic. Furthermore, for any help, you can contact us by commenting in the comments section given below.
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