8051 Microcontroller Based Ultrasonic Object Detection Circuit

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8051 Microcontroller Based Ultrasonic Object Detection Circuit - The ultrasonic sensors are used to detect the article, to measure the space of the article and has many purposes. This text discusses the circuit of the Ultrasonic Object Detection sensor using 8051 microcontroller. The Ultrasonic sensor supplies the simplest methodology of object detection and provides the proper measurement between stationary or shifting objects. The sensor measures the time required for the sound echo to return and ship the identical to the microcontroller as variable width pulse.

Ultrasonic Object Detection Circuit

This circuit is designed to exhibit the detection of an object forward of the ultrasonic transducer. An ultrasonic transducer consists of a transmitter and a receiver. The transmitter produces 40KHz sound wave whereas the receiver detects the 40KHz sound wave and converts it to electrical indicators that are fed to microcontroller.

Block Diagram of Object Detection Circuit

Block Diagram of Ultrsonic Object Detection Circuit
Block Diagram of Ultrasonic Object Detection Circuit


  • Ultrasonic sensor module
  • 8051 microcontroller
  • LCD
  • LED
  • Crystal
  • Transistors, Diodes, Capacitors, and Resistors
  • Transformer
  • Voltage Regulator
  • Magnetic Gun

Software program Requirements

Circuit for Ultrasonic Object Detection

Circuit for Ultrasonic Object Detection
Circuit for Ultrasonic Object Detection

Working Process

This circuit is designed with an 8051 micro-controller and an ultrasonic sensor. The sensor transmits the ultrasonic sound waves of kHz. When an object or impediment comes forward of the sensor, the sound waves are mirrored. Then the receiver detects the kHz sound wave.

The circuitry converts the sound indicators to electrical indicators that are fed to the microcontroller interfaced. The microcontroller receives the indicators and actuates the output to take applicable action. The LCD interfaced to the microcontroller is used to display the standing of the module.

This challenge could be enhanced to calculate the space of the article and discover the placement of the article.

Ultrasonic Sensor

The ultrasonic sensor sends a high-frequency sound pulse and calculates how lengthy it takes for the echo of sound to revert again.

Ultrasonic Sensor
Ultrasonic Sensor

The velocity of sound is roughly 341 meters per second in air. The sensor makes use of the velocity of sound in air and time taken by the sensor to transmit and obtain the sound to calculate the space. Thus detects the article and finds the placement of the article.

Distance = time X (velocity of sound)/2

The sound has to journey from the sensor to object and revert it again so, divide the velocity by 2.


  • Vcc: Enter voltage +5 V
  • GND: Exterior floor
  • Trig: Digital Pin 2
  • Echo: Digital Pin 2

The Trig pin is used to ship the indicators and the Echo pin is used to take heed to the returning indicators.

Be aware: when putting in, join the GND terminal first, in any other case, the module could get broken.


  • Enter voltage: 5 V DC
  • Static present: <2 mA
  • Output voltage: 5 V high and 0 V low
  • Detection vary: 2 cm to 500 cm
  • Dimensions: 3.4 x 2 x 1.5 cm
  • Enter set off sign: 10 us TTL impulse
  • Echo sign: output TTL PWM sign


  • Supplies exact and noncontact distance measurement inside 2cm to 3m vary.
  • Ultrasonic measurement works in any lighting situation, therefore a complement for infrared object detector.
  • Burst indicator LED reveals measurements in progress.
  • 3 pin header makes it straightforward to hook up with growth board instantly or with an extension cable with none soldering.

Purposes of the Ultrasonic sensor

Used to develop safety techniques, interactive animated displays, parking assistance systems and robotic navigation.

8051 Microcontroller

A microcontroller is a extremely built-in chip or a microprocessor with all peripherals like RAM, ROM, I/O ports, Timers ADC and so on. on a single chip. It's a devoted chip known as as single chip laptop.

The 8051 microcontroller is a well-liked 8-bit microcontroller. It's primarily based on 8 bit CISC core of Harvard structure. It's obtainable as a 40 pin DIP pin chip and works with 5volts DC enter.


READ : What is The Difference Between RISC and CISC Architecture


Block diagram of 8051 microcontroller

Block Diagram of 8051 Microcontroller
Block Diagram of 8051 Microcontroller

Salient Options of 8051 Microcontroller

  • 4KB on-chip program memory (ROM and EPROM).
  • 128 bytes on-chip information memory (RAM).
  • 8-bit information bus, 16-bit handle bit and two 16 bit timers T0 and T1
  • 32 normal objective registers every of 8 bits and 5 interrupts.
  • 4 parallel ports every of 8 bits with a complete 32 I/O strains.
  • One 16 bit program counter, one stack pointer and one 16 bit information pointer.
  • One microsecond instruction cycle with 12 MHz crystal.
  • One uninteresting duplex serial communication port.

Pin Description

The 8051 microcontroller is offered in 40 pin DIP configuration. Amongst 40 pins, 32 pins are allotted for 4 parallel ports P0, P1, P2 and P3, every port occupying 8 pins. The remaining pins are VCC, GND, XTAL1, XTAL2, RST, EA and PSEN.

A quartz crystal oscillator is related throughout the pins XTAL1 and XTAL2 with a capacitor worth 30pF. If a source aside from crystal oscillator is used then the pins XTAL1 and XTAL2 are left open.

Serial Communication in 8051 Microcontroller

The 8051 microcontroller has two pins for transferring and receiving the info by means of serial communication. These two pins are a part of a port P3 (P3.0 and P3.1).

These pins are TTL suitable and therefore they require a line driver to make them RS232 suitable. MAX232 is used as a line driver. Serial communication is managed by an 8-bit register known as SCON register.

Purposes of Ultrasonic Object Detection Circuit

  • This challenge can be utilized for purposes like wildlife pictures (Movement Sensing Digicam Set off), safety space monitoring and so on.
  • We will exactly measure distances with Ultrasonic Object Detection Circuit.
  • This circuit can be utilized as a burglar alarm.
  • Used to develop safety techniques, interactive animated displays, parking help techniques and robotic navigation.

Thus, that is all about making of Ultrasonic Object Detection Circuit Utilizing 8051 Microcontroller. We hope that you've got a greater understanding of this idea. Moreover, any queries relating to this subject or wireless technology based projects, please give your helpful strategies by commenting on the remark part beneath.

Source hyperlink : https://www.elprocus.com/ultrasonic-object-detection-circuit-8051-microcontroller/

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