DIY Project:- Digital Meter

Abstract

Measuring length using a measuring tape was never an easy one. Accuracy will be a question mark. Without the help of a second person the job will be tiresome. Here in this DIY project we are trying to develop a digitalized measuring meter which you can use to measure anything up to 10m alone. Be it circle, or any type of geometrical figure you can calculate its length at a stretch without the help of anybody. Really, I am not joking let’s start the process of making this DIY project. 

Block Diagram

Circuit and PCB layout 

Working 

Now let’s understand the working of this amazing DIY project.

Initially you have to set two on/off keys before making the measurement. The first key is the reset button to clear display. Then the next key is hold key which has to be release throughout the measurement. 

In the above block diagram of the DIY project, circle represents a wheel. In this wheel, it has holes each kept at a distance of 1cm. The number of holes in the wheel varies depending upon the size of the wheel. An IR sensor module is attached to the wheel. The transmitter is placed above the wheel and the receiver below the wheel.

The IR transmitter will be continuously sending signals. Being placed below the wheel the detector will detect the pulse only when a hole comes. The detected pulse is given as input to the counter-0. The pulse is detected exactly at a distance of 1cm. While measuring at exact 1cm a pulse will be send to the counter. The counter will keep a count of the distance. Each time a pulse detected counter adds a value 1 to it. Initially they are set as 0.  

When the counter value of counter-0 reaches 10, the value 1 is forwarded to the counter-1. During the transition from 9 to 10 cm the LED-1 will glow. When the value reaches 100, the counter-1 will forward the value to counter-2. During the length 90 to 100, the 10cm distance the LED-2 will glow. The maximum limit set for this digital meter is 1000cm i.e. 10M. When it reaches 900 cm the buzzer will go on.

The three seven segment displays will give the corresponding value of the counters it is connected.

Conclusion

Try this awesome meter to measure any length all alone.