GPS based speedometer using pic microcontroller
GPS based speedometer using pic microcontroller: This project is about how to design speedometer using pic microcontroller without using any speed measurement sensor. In this GPS based speedometer project, I have used GPS module to measure the speed of any person, car, a vehicle with the help of GPS module. GPS module receives data from satellites and this received data can also provide us our speed relative to our position on earth. It used out latitude and longitude relative position to calculate our speed.
In this pic microcontroller based project, I have used Holux GPS module and PIC16F877A microcontroller and an LCD to display speed in kilometer per hour. It can also provide us speed in knots. If you want to make this project you should know how to interface LCD with pic microcontroller and how to interface Holux GPS module with pic microcontroller. Before starting on GPS based speedometer, let me give you some brief introduction on how to interface GPS module with pic microcontroller.
In my last tutorial on GPS module interfacing, I have described how to receive data from GPS module. I will provide a little bit more information about it here. If you want to read more about it, I recommend you to go that article a read it first. So let’s start with little bit introduction, when we powered up GPS module by providing it the power of 5 volts, it will automatically connect with satellites and starts receiving data from them. GPS module will automatically send its data on transmit pin of GPS module. We can receive this data from transmitting pin with the help of serial communication using UART communication of pic microcontroller. So you should know how to use serial communication with pic microcontroller to send and receive data serially. I recommend you to check this post on
We can receive this data from transmitting pin with the help of serial communication using UART communication of pic microcontroller. So you should know how to use serial communication with pic microcontroller to send and receive data serially. I recommend you to check this post on serial communication using pic microcontroller before going further in this article. Some GPS modules work on I2C communication but I recommend you to use those modules which work on serial communication because it is easier to use.
working of GPS based speedometer using a pic microcontroller
So now I am going to explain a working of GPS based speedometer using pic microcontroller. Here I will explain how pic microcontroller receives data from GPS module and how we extract only speed from that data. I have also posted a project on a GPS-based clock and GPS-based coordinates on LCD. In those two projects, I have extracted time and coordinates data from the data received from GPS receiver. But in this GPS based speedometer project, we will extract speed from the $GPVTG string as shown below:
Above commands on GPS NMEA commands which we receive from GPS receiver. We can use any string or any command according to our requirement. But in this project we are using $GPVTG, becuase it is used to track ground speed. Every command provides a unique information. you can check this link for more information on NMEA commands. As shown in above picture, we will use $GPVTG string to extract speed in kilometer per hour. Details of this string are given below:
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