Microcontroller Based Automatic Weighing and Packing Machine

Why Microcontroller based Automatic Weighing system required?

Many Small Scale and Medium Scale industries make their company product Weighing and Packing System manually by utilizing the Labor on daily Wages. All Small Scale and Medium Scale industries utilize this manual system of weighing including a Balance scale or Compact Electronic Weighing Platform of the required range. And packing of weighed Packets is sealed with the help of a candle arrangement or an Electronic Packet Sealing machine and has a lot of drawbacks because it consumes more time and needs sufficient labor effort. And it seems to be hard. To overcome this drawback, The Automation Technology has designed a Microcontroller Based Automatic Weighing and Packing Machine.

Every Small Scale and Medium Scale industries can utilize this system which is of low cost and is easily affordable. This system will eliminate the traditional weighing and sealing system.

Purpose of Microcontroller-based Automatic Weighing system.

Most of the many Small Scale and Medium Scale industries make their weighing and packing operations manually but this is a time-consuming process,

The main purpose of this System is to Increase the Efficiency, Accuracy rate, and weighing speed of the Process in the Industry. But in the market, various types of Weighing Scales are available which are not suitable for industrial applications,

To meet the market needs every Small Scale and Medium Scale Industry must adopt this Automatic weighing and Packing Machine.

What are the components required to build a Microcontroller-based Automatic Weighing system?

Overhead Container:

  • It is a large container made of a High-Grade GI Sheet and is mounted vertically above the ground level tapering downwards. 
  • The storage capacity of the container is very high.  
  • The discharge of the product is based on gravity,

Load cells:

  • A load cell is a transducer that converts a load or weight or force into measurable electrical quantity.
  • The Electronic Signal can be Current, Voltage, or Frequency Signal.
  • It works on the principle of the Piezo-Resistive effect.
  • A change in Resistance causes a proportional change in output Voltage.
  • Every load cell has its calibration certificate that represents its sensitivity.
  • This sensitivity value can be used to convert the load cell’s output signal in terms of weight in kg.
  • These load cells are inflexible andhave very good echo values,
  • These load cells extend forlonger life

To calculate

The raw output voltage of the load cell relative to its rated full capacity can be calculated

Vout = S * VExt

Vout       =                     Output voltage of the load cell in Volts

S           =                     Sensitivity in mV/V

VExt          =                     Load cell excitation voltage. In Volts

Piezo-Resistive effect:  It is a change in electric resistivity of a semiconductor or a metal when mechanical strain is applied to it.

Arduino Uno Board:

Arduino Parts
  • The Microcontroller is a small computer on a single IC that includes Processor, memory, and Input and Output Peripherals.
  • The Arduino Uno is a Microcontroller board based on the ATmega328.
  • It has 14 digital input/output pins (of which 6 can be used as PWM outputs), and 6 analog inputs.
  • It is a 16 MHz crystal oscillator with a USB interface connection and a power jack, an ICSP header, and a reset button.
  • It can easily be connected to the computer via USB Port.
  • It can be easily powered through a power Jack using a 5V AC-to-DC adapter or battery.
  • Arduino Uno has its Integral Development Environment (IDE) that uses C-programming language.
Some of the Technical Specifications of Arduino Uno are listed below
  • Input Voltage (recommended) 7-12V
  • DC Current per I/O Pin 40 mA
  • DC Current for 3.3V Pin 50 mA
  • Flash Memory 32 KB of which 0.5 KB used by boot loader
  • SRAM 2 KB
  • Clock Speed 16 MHz

Stepper motor: 

Stepper Motor
Stepper Motor
  • A Stepper Motor is a DC motor that moves in discrete steps dividing the full rotation into several equal Steps.
  • The precise positioning or Speed of the Stepper motor can be easily controlled by a computer.
  • These are the choice of many Precision Motion Control Applications.
  • The driver is an electronic circuit that drives the stepper motor through the instructions received by the controller


  • A keypad is an Input device,
  • It is a mini board with a  set of keys having digits, symbols, and alphabets
  • It is used for Input to a machine,
  • This keypad offers both upper and Lower case alphabets for typing.
  • It has a female 8 Pin Berg Connector for interfacing with the Microcontroller
  • This allows a processor to scan the 8 output Pins to check which of the 16 buttons is being keyed.

Liquid Crystal Display

The LCD Pinout Details of interface pin functions

The LCD has 16 pins:

  • PIN 1 is the VSS or Ground pin.
  • PIN 2 is the VDD that provides a 5 volt DC supply to the Arduino Board.
  • PIN 3 is V0 which controls the brightness of the display through a variable potentiometer.
  • PIN 4 is the RS pin that selects Command / Data to the LCD.  If RS is low, the command is sent, if RS is High Data is sent to LCD.
  • PIN 5 isthe R / W pin which selects the mode to LCD
  • PIN 6 is the E pin that enables the writing to the registers, or the next 8 data pins
  • Pin 7 – Pin 14 D0 to D7 These Pins sends 8-bit data to the Registers.
  • Pin 15  is Anode (A) and
  • Pin 16 (A) and Cathode(K) are for the LED backlight.
LCD Pin Details

  1VSS or GND (0 V)
  2VDD (5V)
  6E ( ENABLE)
  7D0        Data Bus
14 D7
  15A   Anode 5V
  16K  Cathode (GND)
Pin details of LCD

How Microcontroller based Automatic Weighing system works?

  • The product to be weighed and packed is received from the process station via conveyor and is stored in a large Over Head tank or Silo.
  • This Microcontroller Based Automatic Weighing and Packing Machine consists of an overhead container or Silo in which the material to be weighed and packed is stored. 
  • The Material from the Overhead container or Silo is discharged through gravitation to the weighing machine Platform.
  • The weighing machine platform consists of a U-shaped basket along with the load cells and a stepper motor fixed to it.
  • The Flap is fixed at the bottom of the basket that acts as a door mechanism
  • The Stepper Motor rotation makes the flap open and close the basket.
  • The Stepper motor is used to provide the stable speed of the Flap Opening or closing
  • The Plastic / Paper bags are held manually at the bottom of the basket.
  • The Microcontroller sends the ready signal to the load cell.
  • Now the product is placed on the platform that creates Pressure on the load cell which is directly proportional to the weight added.
  • The load cell converts the force or load into a proportional electric current, voltage, or Frequency Signal. Using the Principle of Piezo-resistivity.
  • The Weight is done depending upon the instructions received by the microcontroller.
  • The input is given with the help of a 4X4 keypad connected to the system that allows the operator to weigh the material at the desired quantity and the weighted value is indicated on LCD Display.
  • The Arduino Uno (Microcontroller) is the main component and has a customized program written depending upon the required weighing to be done.
  • The Program is a set of instructions written in C Programming language and is stored in its memory.
  • After the weighing is done the flap is opened through the Stepper motor and the product is dropped in the bag.
  • The weighing process is a Batch Type of Process.
  • After the completion of the Current Weighing process, the cycle is again repeated
  • Finally the bag is packed with the Sealing the Stitching Machine.

The main objectives are:

  • To increase Efficiency.
  • Eliminates Human efforts.
  • The weighing is accurate.
  • Bag Packing is neat and hygienic.


  • System is Cheaper
  • Requires Less Installation Space


Can’t be used for large scale Industrial Applications


  • Small Scale or Medium Scale Food Production Industries
  • Pharmaceutical Industries
  • This system makes it Helpful for Farmers to weigh and pack their Agro-based Products.

Related Articles

Back to top button