View source for OpenPLC-with-LDmicro/C2/Implementing-OR-and-XOR-logic-gates/English


{| style="border-spacing:0;"
| style="border:1pt solid #000000;padding:0.176cm;"| <center>'''Visual Cue'''</center>
| style="border:1pt solid #000000;padding:0.176cm;"| <center>'''Narration'''</center>

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 1: 
| style="border:1pt solid #000000;padding:0.176cm;"| Welcome to the spoken tutorial on '''Implementing OR & XOR logic gates'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 2: Learning Objectives

How to implement logic gates

* OR
* XOR

| style="border:1pt solid #000000;padding:0.176cm;"| In this tutorial, we will implement '''OR & XOR logic gates''' in '''LDmicro'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 3: System Requirements

* Ubuntu 18.04''' '''OS
* LDmicro
* OpenPLC Mainboard
* 24V, 2A SMPS
* USBasp programmer
* Traffic Light module
* Switchboard module

| style="border:1pt solid #000000;padding:0.176cm;"| To record this tutorial I am using:

* '''Ubuntu Linux 18.04''' operating system
* '''LDmicro'''
* '''OpenPLC Mainboard'''
* '''24V, 2A SMPS'''
* '''USBasp''' programmer
* '''Traffic Light''' module and 
* '''Switchboard''' module

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 4: Pre-requisites

* Normal Contact and Coil
* Negated Contact and Coil

| style="border:1pt solid #000000;padding:0.176cm;"| 
* To follow this tutorial, you should know the working of 
# '''Normal Contact''' and '''Coil'''
# '''Negated Contact''' and '''Coil'''

* If not, please refer to the relevant tutorials in this series on this website.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 5: Prerequisites - Hardware setup


hardware-prerequisite.jpg
| style="border:1pt solid #000000;padding:0.176cm;"| Connect''' SMPS''' and '''USBasp''' to the '''Mainboard''' as shown in the picture.

Keep these connections throughout this tutorial.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| First we will see how to implement '''OR gate'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 6: OR gate

'''OR''' gate outputs 0 only when all of its inputs are 0
| style="border:1pt solid #000000;padding:0.176cm;"| We know that '''OR gate''' outputs 0 only when all of its inputs are 0.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Open LDmicro
| style="border:1pt solid #000000;padding:0.176cm;"| Let us open '''LDmicro'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Click Instructions -> Insert Contact

Place the cursor to the right of Xnew >> 
Click Instructions -> Insert Coil
| style="border:1pt solid #000000;padding:0.176cm;"| Insert a '''Contact''' and a '''Coil''' as shown.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xnew
>> Type ‘switch1’ in the name box 
>> Click OK button 
| style="border:1pt solid #000000;padding:0.176cm;"| Rename the '''Contact''' as '''‘switch1’.'''

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Ynew 
>> Type ‘LED’ in the name box 
>> Click OK button 
| style="border:1pt solid #000000;padding:0.176cm;"| Then, rename the '''Coil''' as '''‘LED’.'''

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Place the cursor to the below Xswitch1
>> Click Instructions -> Insert Contact
| style="border:1pt solid #000000;padding:0.176cm;"| Now place the cursor below '''Xswitch1 '''and insert a '''Contact'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xnew 
>> Type ‘switch2’ in the name box 
>> Click OK button
| style="border:1pt solid #000000;padding:0.176cm;"| Rename the new '''Contact''' as '''’switch2’'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| We will now check the working of this '''logic'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Click Simulate -> Simulation mode 
>> Click Simulate -> Real-time simulation
| style="border:1pt solid #000000;padding:0.176cm;"| Let us turn '''on''' the '''simulation mode'''.

For that, click '''Simulate''' and then on '''Simulation mode.'''

Next, start '''real-time simulation''' as shown.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Highlight the state of Xswitch and YLED
| style="border:1pt solid #000000;padding:0.176cm;"| Initially the states of both the '''Contacts''' and '''Coil''' are 0.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xswitch1 >> Highlight the state of the ‘YLED'
>> Double-click on Xswitch1 
| style="border:1pt solid #000000;padding:0.176cm;"| Change the state of '''Xswitch1''' to 1.

We can observe the state of '''YLED''' is 1.

Change the state of '''Xswitch1''' back to 0.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xswitch2 
>> Highlight the state of the ‘YLED'
| style="border:1pt solid #000000;padding:0.176cm;"| Now, change the state of '''Xswitch2''' to 1.

We can observe the state of '''YLED''' is 1.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xswitch1
>> Highlight the state of the ‘YLED'
| style="border:1pt solid #000000;padding:0.176cm;"| Now again change the state of '''Xswitch1''' to 1.

We can observe that the state of '''YLED''' is 1.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| That is, output state is 0 only when both the inputs states are 0.

Thus, resembling the '''truth table''' of an '''OR gate'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Click Simulate -> Halt Simulation
>> Click Simulate -> Simulation Mode
| style="border:1pt solid #000000;padding:0.176cm;"| Now, turn '''off''' the '''simulation mode'''.

For that, click '''Simulate''' and then on '''Halt Simulation.'''

Then click '''Simulate''' and '''Simulation Mode.'''

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| Now let us '''compile''' the '''logic'''.

The detailed steps on how to '''compile''' and save the '''logic''' are explained in the earlier tutorials. 

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Click on Settings >> Click on Microcontroller
>> Select AVR ATmega16 40-PDIP 

Click on Settings 
>> Click on MCU parameters 
>> Change Crystal frequency to 16
| style="border:1pt solid #000000;padding:0.176cm;"| Click on '''Settings''' and select the '''microcontroller AVR ATmega16 40-PDIP.''' 

Adjust its '''parameters''' as shown here.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xswitch1 in the I/O list>> Select PC0
>> Click OK button
Double-click on Xswitch2 in the I/O list 
>> Select PC1 >> Click OK button


Double-click on YLED in the I/O list>> Select PA0 >> Click OK button
| style="border:1pt solid #000000;padding:0.176cm;"| Assign '''pin PC0''' to '''Xswitch1''' and '''PC1''' to '''Xswitch2'''.

Assign '''PA0''' to '''YLED.'''

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Compile
| style="border:1pt solid #000000;padding:0.176cm;"| '''Compile''' the '''logic''' as '''‘orgate.hex’'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Save the file
| style="border:1pt solid #000000;padding:0.176cm;"| Save the file as '''‘orgate.ld’''' as shown.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| Now we will see the working of this '''logic''' on hardware.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Connect Mainboard to PC using USBasp

laptop-usbasp.jpg


| style="border:1pt solid #000000;padding:0.176cm;"| Connect the '''Mainboard''' to your laptop using '''USBasp'''.

Turn '''on''' the '''power supply'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Open terminal >> Type cd Desktop/LDmicro >> Press ENTER >> 


type ‘'''avrdude -c usbasp -p m16 -U flash:w:orgate.hex’ '''>> Press ENTER
| style="border:1pt solid #000000;padding:0.176cm;"| Open the '''Terminal''' by pressing '''CTRL+ALT+T''' keys simultaneously.

Go to the folder where you have saved the '''hex file'''.

Type the '''command''' as shown to upload the '''hex''' file to the '''Mainboard'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Remove the '''USBasp''' connection from the laptop.
| style="border:1pt solid #000000;padding:0.176cm;"| Turn '''off''' the '''power supply'''.

Remove the '''USBasp''' connection from the laptop.

This will prevent any hardware damage.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Display the image orgate.png
| style="border:1pt solid #000000;padding:0.176cm;"| Let us see the connection details now. 

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Display the image orgate.png
| style="border:1pt solid #000000;padding:0.176cm;"| Connect '''GND pin''' of the red '''LED''' of '''Traffic Light module''' to '''GND pin''' of the '''Mainboard'''.

Then connect the '''+5V pin''' of the red '''LED''' to '''PA0 pin''' of the '''Mainboard'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Display the image orgate.png
| style="border:1pt solid #000000;padding:0.176cm;"| Connect '''GND''' and '''5V''' of '''Switchboard''' to '''GND''' and '''5V''' of the '''Mainboard''' respectively.

Connect '''NO1''' to '''PC0''' of the '''Mainboard'''.

Connect '''NO2''' to '''PC1''' of the '''Mainboard'''.

Make the connections as shown in the picture.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Switch on the power
| style="border:1pt solid #000000;padding:0.176cm;"| Turn '''on''' the '''power supply'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Point to red LED
| style="border:1pt solid #000000;padding:0.176cm;"| We can see that the red '''LED''' is '''off''' initially.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Press any one switch 

Press both the switches
| style="border:1pt solid #000000;padding:0.176cm;"| It will start glowing when either one of the '''switches''' is pressed.

It will also glow when both of the '''switches''' are pressed at the same time.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| Thus, for an '''OR gate''' the inputs i.e. '''Contacts''' should be parallel to each other.

The output i.e. '''Coil''' should be in series with both the inputs.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Switch off the power
| style="border:1pt solid #000000;padding:0.176cm;"| Turn '''off''' the '''power supply'''.

Remove the connections made for this example.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| We will now learn about '''XOR gate'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 6: XOR gate

Boolean equation:

*A’B+A’B - (('''NOT''' A) '''AND''' B) '''OR''' (A '''AND''' ('''NOT''' B))

*It is a combination of NOT, AND and OR gates
| style="border:1pt solid #000000;padding:0.176cm;"| We know the '''boolean''' equation of an '''XOR gate''' with inputs '''A''' and '''B''' will be '''AB’+A’B'''.

Thus it is a combination of '''NOT''', '''AND''' and '''OR gates'''.

|-

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| We will now see how to implement it on '''LDmicro'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Switch back to LDmicro
| style="border:1pt solid #000000;padding:0.176cm;"| Switch back to '''LDmicro'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| Instead of creating a new file, we will make changes in the previous file itself.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Place cursor to the right of Xswitch1 >> Click Instructions -> Insert Contact >> Double-click on Xnew >> Check the Negated box >> Type switch2 in the name box >> Click OK button
| style="border:1pt solid #000000;padding:0.176cm;"| Insert a '''Contact''' to the right of '''Xswitch1'''.

Configure it as '''Negated''' and rename it as '''switch2''' as shown.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Place cursor to the right of Xswitch2 >> Click Instructions -> Insert Contact >> Double-click on Xnew >> Check the Negated box >> Type switch1 in the name box >> Click OK button
| style="border:1pt solid #000000;padding:0.176cm;"| Then insert a '''Contact''' to the right of '''Xswitch2 '''which is in the parallel rung.

Configure it as '''Negated''' and rename it as '''switch1''' as shown.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| We will now check the working of this '''logic'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Click Simulate -> Simulation mode >> Click Simulate -> Real-time simulation
| style="border:1pt solid #000000;padding:0.176cm;"| Start '''real-time simulation''' as shown.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Highlight the state of Xswitch and YLED
| style="border:1pt solid #000000;padding:0.176cm;"| Initially the state of both the '''Contacts''' and '''Coil''' are 0.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xswitch1 >> Highlight the state of the ‘YLED' >> Double-click on Xswitch1
| style="border:1pt solid #000000;padding:0.176cm;"| Change the state of '''Xswitch1''' to 1.

We can observe the state of '''YLED''' is 1.

Change the state of '''Xswitch1''' back to 0.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xswitch2 >> Highlight the state of the ‘YLED'
| style="border:1pt solid #000000;padding:0.176cm;"| Now, change the state of '''Xswitch2''' to 1.

We can observe the state of '''YLED''' is 1.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Double-click on Xswitch1 >> Highlight the state of the ‘YLED'
| style="border:1pt solid #000000;padding:0.176cm;"| Now again change the state of '''Xswitch1''' to 1.

We can observe that the state of '''YLED''' changes to 0.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| That is the output state is 0 when both the inputs have the same state.

Thus, resembling the '''truth table''' of an '''XOR gate'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Click Simulate -> Halt Simulation >> Click Simulate -> Simulation Mode
| style="border:1pt solid #000000;padding:0.176cm;"| Turn '''off''' the '''simulation mode''' as shown.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| Now let us '''compile''' the '''logic'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Highlight I/O list and status bar
| style="border:1pt solid #000000;padding:0.176cm;"| We can observe that the '''microcontroller''' and its '''parameters''' are already set.

'''Pin''' assignment is also already done.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Click on Compile >> Click on Compile As >> Go to Desktop/LDmicro folder >>


Rename it as ‘xorgate.hex’ >> Click on Save.

Click OK button
| style="border:1pt solid #000000;padding:0.176cm;"| '''Compile''' the '''logic''' as '''xorgate.hex '''using '''‘Compile As’''' option.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Click on File >> Click on Save As >> Go to Desktop/LDmicro folder >> 

Rename it as ‘xorgate.ld’ >> Click on Save
| style="border:1pt solid #000000;padding:0.176cm;"| Then save the '''ladder diagram''' as '''‘xorgate.ld’''' using the '''‘Save As’ '''option.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| Now we will see the working of this '''logic''' on hardware.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Connect Mainboard to PC using USBasp

laptop-usbasp.jpg


| style="border:1pt solid #000000;padding:0.176cm;"| Connect the '''Mainboard''' to your laptop using '''USBasp'''.

Turn '''on''' the '''power supply'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Open terminal >> Type cd Desktop/LDmicro >> Press ENTER >> 


type ‘'''avrdude -c usbasp -p m16 -U flash:w:xorgate.hex’ '''>> Press ENTER
| style="border:1pt solid #000000;padding:0.176cm;"| Switch back to the '''terminal'''.

Type the '''command''' as shown to upload the '''hex''' file to the '''Mainboard'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Remove the '''USBasp''' connection from the laptop.
| style="border:1pt solid #000000;padding:0.176cm;"| Turn '''off''' the '''power supply'''.

Remove the '''USBasp''' connection from the laptop.

This will prevent any hardware damage.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Display the image xorgate.png
| style="border:1pt solid #000000;padding:0.176cm;"| Let us see the connection details now. 

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Display the image xorgate.png

Switch on the power

| style="border:1pt solid #000000;padding:0.176cm;"| The connections will be same as in the '''OR gate '''example.

Turn '''on''' the '''power supply'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Point to red LED
| style="border:1pt solid #000000;padding:0.176cm;"| Initially the red '''LED''' is '''off'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Press any one switch >> Press both the switches
| style="border:1pt solid #000000;padding:0.176cm;"| It will start glowing only when either of the '''switches''' are pressed, but not both.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Switch off the power
| style="border:1pt solid #000000;padding:0.176cm;"| Turn '''off''' the '''power supply'''.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| 
| style="border:1pt solid #000000;padding:0.176cm;"| This brings us to the end of this tutorial.

Let us summarize.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 7: Summary

How to implement logic gates

* OR
* XOR 

| style="border:1pt solid #000000;padding:0.176cm;"| In this tutorial we learnt to implement '''logic gates''' 

* '''OR''' and
* '''XOR'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| Slide 8: Assignment: 

Implement 2 input XNOR logic gate
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| As an assignment, try to implement 2 input '''XNOR logic gate'''.

'''Truth table''' of '''XNOR gate''' is shown here.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 9:

About Spoken Tutorial project
| style="border:1pt solid #000000;padding:0.176cm;"| The video at the following link summarises the Spoken Tutorial project.

Please download and watch it.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 10:

Spoken Tutorial workshops
| style="border:1pt solid #000000;padding:0.176cm;"| The''' Spoken Tutorial Project''' team:

* conducts workshops using spoken tutorials and
* gives certificates on passing online tests.

For more details, please write to us.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 11:

Forum for specific questions:
| style="border:1pt solid #000000;padding:0.176cm;"| Please post your timed queries in this forum

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 12:

Forum for specific questions:
| style="border:1pt solid #000000;padding:0.176cm;"| 
*Do you have any general / technical questions on OpenPLC?

*Please visit the FOSSEE forum and post your question.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 13:

Acknowledgement
| style="border:1pt solid #000000;padding:0.176cm;"| Spoken Tutorial Project is funded by MHRD, Government of India.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide 14:

Thank you slide
| style="border:1pt solid #000000;padding:0.176cm;"| This tutorial has been contributed by FOSSEE and Spoken Tutorial Project, IIT Bombay.


And this is Harsha Priyanka from FOSSEE team, signing off.


Thanks for watching.

|}