circuit explanation (L293D motor driver)

In this DICM circuit, L293D motor driver is used to control the DC gear motor movements. For example move forwards, backwards and stop. Picture below shown the L293D motor driver in DICM circuit 

Theory

Generally, L293D motor driver can control two motor at one time or called is a dual H-Bridge motor driver. By using this IC, it can interface DC motor which can be controlled in both clockwise and counter clockwise direction. The motor operations of two motors can be controlled by input logic at pins 2 & 7 and 10 & 15. Below shown the pin diagram of L293D motor driver

and the pin description of L293D motor driver

Besides that, with this L293D driver motor it will control four DC motors at one time but with fix direction of motion. L293D has output current of 600mA and peak output current of 1.2A per channel. Moreover for protection of circuit from back EMF output diode are included within the L293D. The output supply hich is external supply has a wide range from 4.5V to 36V which has made L293D a best choice for DC motor driver. A simple schematic for interfacing a DC gear motor using L293D driver motor is shown below:

and below the truth table for L293D driver motor

 For truth table above, the Enable has to be set to 1 and motor power used is 12V but it is depends on motor power that used (range 4.5V to 36V). The rotation of the DC motor can be control by combinations of A and B in programming assembling and from the truth table it is clear to explain the rotations of the motor. Picture below shown the connection of DC gear motor to L293D driver motor. 

DICM system

In DICM system,  the movement of the DC gear motor is controlled by the output from the micro controller  which is Atmega 328. The input of this micro controller are IR sensor which are detect the obstacle and to detect the crops. The output from this micro controller which is in digital signal (0 or 1) will sent to the L293D driver motor as a input which are connected to input 1 and input 2 ( pin 2 and pin 7). The connection of this L293D is shown in the PCB design below. 

With this input, it will determine the movement of the DC gear motor. The combination of the input will be summarized in the table below. 

* Pin 3 and pin 6 is the output of the L293D

By referring the picture and truth table above, the DC gear motor will be controlled by changing the input 1 and input 2 (pin 2 and pin 7). The changing movement of this DC gear motor will be programmed or setting to be high or low in the programming of this DICM system. Picture below shown the connection of DC gear motor to L293D driver motor.

Testing DICM system

The DICM system has been tested on iron. The following picture shows the result of this DICM system without use the real crops. It is just to test the function of each sensor that used and each component used on this DICM system either function or not .

~ At the beginning,

~ Forward,

~ Once this DICM system detect the crops,

 process mode means that this DICM system is fertilizer and pesticide the crops

~ Once this DICM system detect the obstacle in front of this DICM system,

This command shows that this DICM system detect the obstacle. Obstacles in this system shows it has two

obstacles which are human or animal in front of this system and another obstacles is this system is reached at the end of the iron. If this system reached at the end of the iron, another command which is "Hold red switch" will display to notify the user to hold the red switch and lastly this system will be reversed  

~ Once the red switch was pressed, 

When in "reverse mode", this system will reverse back at to beginning until the switch was pressed and this system will automatically off. 

DICM system

The following picture shows the overall view of this DICM system. 


Front view

Back view

Side view

DICM system

This is the actual shape of DICM system that was developed during this semester. The following picture shows the front view and side view of this DICM system.

~ Front view

~ Side view

~ overall view 

Make the mechanical parts

The purpose of this mechanical parts is shows how this DICM system moves on the rod of iron. This mechanical parts have been made in Sekyen 17, Shah Alam. Picture below shows the process to make the mechanical parts. 

The workshop map:

Design of mechanical parts:

Making mechanical parts process: 

~ Measuring

~ Cutting

~ Drilling 

~ Soldering 

~ Complete mechanical parts

By doing this mechanical parts, the DICM system is ready to testing on this iron. 

Assemble DICM circuit in the boxes

This procedure is important to protect the circuit from damage. Besides that, it will protect all the electronic components and wire's from heat and water and in addition, it will be used to placing the DC gear motor on the top and placing the water sprinkler tank at the side of boxes.  The assembling DICM circuit in the boxes process are shown in picture below:

DICM system (front view) 

* Tools and equipment used:

~ Screw driver

~ Test pen

~ Long nose

~ Soldering iron 

~ screw (set)

Assemble the components

Below are the some of components used for this DICM system:
~ Solenoid motor 12V
~ DC gear motor 12V
~ DC motor for water sprinkler 12V
~ Liquid Crystal Display (LCD)
~ IR sensor
~ Buzzer 
~ IC driver motor
~ Power transistor 
~ Crystal
~ Resistor
~ Capacitor
~ Diode
~ etc 

Picture below show the components that used in this DICM system: