Introduction

A solar-based Solar Powered seed sowing machine  is an electronic machine that implants seeds into the soil, relying on energy from the sun. The purpose of this robot is to place precise and even spaced seeds to enhance productivity and reduce time consumption.

This project will provide a better agriculture solution with a minimized cost. The main component of this project is the solar panel that will convert the solar energy into electrical energy which will be accumulated in the battery to provide the necessary power to DC motors to move the wheels. The sensors will help the robot in maneuvering and positioning. To pick and place seeds, we have used seeding disc that picks seeds from seed container and drop seeds with equidistance from the successive point. The device can be easily maintained because it consists of a modular structure. Overall, the proposed system is cost-effective, power-efficient, and user friendly that makes it suitable for all farmers.

seed sowing robot
solar powered  Seed Sowing Machine

Block Diagram

 Implementation is done stepwise by following the block diagram. Block diagram of Automatic seed sowing machine is given below.
seed sowing robot
Block diagram

Hardware Components

Components that we required to complete our hardware system are listed below.

DC Geared Motors 

AMETEK PITTMAN GM9232C113-R4 12/24VDC motors are used for robot movement purposes (Source).
GM stands for gearhead motors. The engine can operate on 12V as well as on 24V in case of a high load. Motor’s Revolution is 50 rpm at 12V and 100 rpm at 24V. As this motor is low rpm and high torque motor, that’s why it is more reliable for our application. These motors provide low and smooth speeds and are designed for long life. The geared ratio for GM9232C113-R4 is 65:5:1. There are three possibilities of the gear that are used in this motor.
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Possibilities of torque
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Dc gear Motors

Foldable Solar Panel 

A photovoltaic solar panel is a device that absorbs solar energy and then converts it into electrical energy. This type of power is the cleanest source of energy.
seed sowing robot

Specifications of Solar panel

 

seed sowing robot
foldable Solar Panel seed sowing machine

Bluetooth Module HC-05 

HC-05 is a Bluetooth-Module that is used for wireless communication between microcontrollers (Arduino) or communication between devices that have Bluetooth functionality. It is a wireless module that has a range of 30 feet approximately. A few technical specifications are given below. (1) Serial Bluetooth-module for Arduino mega 2560 microcontrollers. (2) Operating-Voltage 4V to 6V (3) Operating-Current 30mA (4) It can easily be interfaced with the laptop and all other devices that have the functionality of Bluetooth. (5) Baud Rate 9600 (baud/s)

Monster Motor Shield VNH2SP30 

VNH2SP30 is a full motor driver module that is used to control the movement of motors. It is much better than the L298N Motor driver circuit because its power rating is much higher than L298N. The motor drivers have maximum current ratings of 30A continuous.
seed sowing robot
Monster Motor Shield
Ultrasonic Sensor HC-SR04 
The ultrasonic sensor is a sensor that is used to measure the distance based on transmitting and receiving ultrasonic signals.HC-SR04 is used in microcontrollers and microprocessors like Arduino, PLC, and Raspberry pie. It has 4 pins VCC, Trigger, Echo and Ground. Specification table of HC-SR04 is given below.
seed sowing robot
Ultra Sonic Sensor

Lead Acid Battery

The battery is used for storage purposes from Solar panels. 12V, 7.2Ah Battery is used to power up our project. The battery is long life and rechargeable and maintenance-free. Internal resistance is 22mOhm at 1000 Hz.

LCD Display 16*2 16*2

 LCD is used to display the status of  solar powered seed sowing machine movement. It has 16 columns and 2 rows. Interface LCD with Arduino microcontroller and view the status of solar powered seed sowing machine status (left, right, forward, backward).
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LCD Display

Relay Module

The relay module is a device that can be used for switching purposes, which is a valuable part of the solar powered seed sowing machine. It turns into electromagnet when current flows through the coil. Relay is an electrically operated switch that can turn on or off, and can be controlled with low voltage (5V) that are provided by Arduino microcontroller. We use a relay module that has 2 channels, and it is a type of SPDT(single pole double throw) relay…

seed sowing robot

2 channel Relay Module solar powered seed sowing machine

LM2596 DC-DC Buck Converter Module

LM2596 series of the regulator are monolithic integrated circuits that use to step-down voltages (Voltage-Buck). It can drive a 3A load with line and load regulation. DC- Buck converter that we are using has an adjustable output, but module with fixed output voltage like 3.3V, 5V, 12V also available. It has an internal 150 kHz fixed frequency Internal Oscillator (Data sheet of LM2596).
seed sowing robot
LM 2596

Tires 

The tires of the solar powered seed sowing machine is Rubber tires with 6-inch diameter are used for robotic designing. Rubber tires that we selected have large friction so that tires don’t slip when they move. As the diameter of the tire is about 6 inches, which is 15.24 in centimeters. Hence radius is given as
 r=d/2= 15.24cm/2=7.62cm
 r=0.0762m
circumference=0.478m
 In one complete Revolution of the tire, it covers the distance of half a meter.
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  Tire

 Implementation of Sepic Converter

As the demand for clean and sustainable energy sources has been increased. Solar energy is the most honest, valuable, low maintenance, and abundant in nature.
PV systems require a DC-DC converter to regulate the the varying voltage from the solar panel due to different intensity of light at day time.
A technique is SEPIC (Single-Ended Primary Source Inductance. Converter) works as a buck-boost converter. If voltage is high from PV module nearly 18V, it Buck the energy to fixed 12-13V, to charge DC battery. If tensions are below 12V in evening time due to low intensity of light, it boosts the voltage to fixed 12-13V. As the Buck converter can reduce input voltage, the Boost converter can increase the input voltage, but a SEPIC or Cuk converter can increase or decrease the input voltage. In buck-boost converter polarity is reversed, but in the SEPIC converter, polarity at output remains the same.
SEPIC converter gets input voltage from the solar panel and charges DC battery. The necessary PWM is provided by the Arduino microcontroller.
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Block Diagram of Sepic Converter

Circuit Diagram of SEPIC Converter

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   Circuit Diagram of Sepic Converter

Continuous Conduction Mode

During continuous conduction mode, the current through inductor L1 not falls to zero. During steady-state operation, so VC1 is equal to Vin because  C1 blocks the DC current. Now, L2 does not depend on input voltage; hence average flow through L2 is the same as the average load current.
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fig 1.1 On State
Since the voltages are of the same magnitude, the ripple currents from the two inductors are also of the same size. The average flow is now assumed to be.

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figure 1.2 Off State
Figure 1.1 shows the ON-State.
 When the switch is on Vc1=Vin, VL2=- Vin, the current through inductor IL1, increases at the same time current through inductor L2 (IL2) proportionally decreased. When the first inductor L1 is charged with Vcc, Inductor L2 is charged with capacitor C1 energy.
Figure 1.2 shows the OFF state when the switch is OFF, the branch is open circuit. Current through C1 is the same as through L1. In L2 current flows in the reverse direction. This present added with L1 current and increased the current at load.

Discontinuous Mode of Conduction

Current through first inductor L1 is approximately zero in during discontinuous conduction mode.

Mathematical Design

Simulation of SEPIC Converter

seed sowing robot
Simulation of Sepic Converter
seed sowing robot
Circuit Diagram

Results

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PWM Signal
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Output Voltage
solar powered seed sowing machine

System Evaluation and Testing

Structure Testing

 As the first part of our solar powered seed sowing machine is foundry work. The Structure is made from an iron pipe that can bear a load of components. When hardware is made, it is tested either it is aligned or not. The Testing of Structure is given in the figure.
Solar Powered Seed Sowing Machine
Structure
As the Structure is not aligned and it is not moving in a straight line, that’s why we made some changes in it and make it aligned. After all, the alignment issues have removed.

Solar Panel Working 

Open circuit voltage (VOC) is a voltage at no load. Open circuit voltage (VOC) can be measured by connecting multimeter in parallel with Solar panel. So open-circuit voltage (VOC) is 22V approximately. When a load is connected than at pressure, the mean maximum power voltage is 18V almost. To check short circuit current (ISC) of the solar panel quick the solar panel and compare it with a multimeter, hence short circuit current (ISC) is approximately 7.06A. But when the load is connected, then the maximum power current of this panel is 6.67A almost.
Solar Powered Seed Sowing Machine
solar panel testing and working

Battery Working

We use the lead-acid battery that has a capacity of 12V, 7.2Ah capacity.
At first, battery, charging should be checked. Connect DMM to it and check the voltages. Check battery. Either it is charged. To charge the battery, we connect it with a Solar panel through a charge controller and charge DC battery.
Solar Powered Seed Sowing Machine
battery charging through the solar panel

solar powered seed sowing machine

 

SEPIC Converter Testing

SEPIC converter is used to charge DC battery from the solar panel. SEPIC converter is a DC-DC converter that can buck-boost the voltage with no change in polarity of the voltage at the output. As the efficiency of the SEPIC converter is Solar Based Seed Sowing Robot 53 high so it can charge the battery in less time. P75nf75 planer N-Channel power MOSFET is used for off-line switch mode power supply. As the PWM signal is required, so we generated a PWM signal from the Arduino microcontroller. Hardware circuit of the SEPIC converter is given below in figure, and the PWM signal waveform on Oscilloscope is also provided in figure.
Solar Powered Seed Sowing Machine
Hardware Testing
Solar Powered Seed Sowing Machine
Oscilloscope Results

Final Look and Results

Movement of Robot Testing 

Interface monster motor shield VNH2SP30 with Arduino microcontroller. Attached motors with a monster motor driver circuit and test the movement of the tire by writing commands in Arduino (low, High). Test the movement of Robot on left right and in forwarding and in the reverse direction. Battery, Sepic converter, Arduino, and solar panel are interfaced and test the movement solar powered seed sowing machine as well as battery charging. Fig shows the Testing of the robot.
Solar Powered Seed Sowing Machine
Robot Movement Testing

Seeding Assembly Testing 

When we achieve the goal to control the movement solar powered seed sowing machine robot, we design seeding assembly. For this purpose, we made a disc, interface it with motor and then place it in seed container, then test either it is picking seeds or missing them. The drive should pick seeds so that distance between each grain can be maintained. Fig showing the Testing of seeding assembly.
Solar Powered Seed Sowing Machine
Seeding Testing

Final Testing

All parts and components are interfaced with each other and final Testing done. After that, we also do Testing in fields to check the seed rate and seed distance. The solar powered seed sowing machine is covered by the Acrylic sheet. The final system is given in the figure.

 

Solar Powered Seed Sowing Machine
final Testing

Conclusion

This Solar powered seed sowing machine is designed to eliminate the trouble of manually sowing seed, and give an optimal solution for planting different kinds of seeds with ease and precision we believe this is the right choice for the farmers and for those people who are in short of laborers and businessman who wants to generate massive revenue without disturbing the environment.