Arduino Tutorial 49: How to Build a Simple Calculator with LCD Display

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In lesson 48 we gave the homework assignment to create a simple calculator that could add, subtract, multiply and divide using the arduino, and then creating a nicely formatted output on the LCD. In this lesson we take you through the solution to the assignment

You can get the kit I am using for this series at the following link:

As projects get more complicated in these lessons, you guys really need to get a set of breadboard jumper wires which allow you to make neater connections on the board in your projects. You can pick a pack of these wires up here:

In addition as projects get more complicated, you are going to need a bigger breadboard. This is a reasonable one here:

Follow these lessons and other great content on our Free WEB site;

#Arduino

[manavt]

I wish you have 10 million subscribers one day. Keep going ✨

[emiliomartineziii]

I did the entire homework successfully without even needing to watch the video!

[fatihakyildiz]

Paul, you are Bob Ross of electronics. Thank you.

[TheShocker]

First off, thank you for this series of tutorial videos! I have learned so much from them.
I decided to give myself my own homework on this one, and made a calculator that will solve the Pythagorean Theorem for one missing variable! Looking forward to future videos!

[fun_engineering]

This was really a good lesson, and all your other lessons. I hope you keep going. I'm a high school hobbyist of engineering who stayed for 3 years searching for someone to help me, and finally found my teacher.
I did the homework but with a little trick, instead of displaying the ans for a period of time I added a button that once clicked it clears the ans and repeats the program.
Thanks a lot Sir.

[hughpatterson]

Another fantastic lesson Paul! Students will love this because they are building and programming something they are familiar with in the real work, a calculator. I've been purposely throwing mistake into my lessons to see if my students notice them. I'm also going to start asking them to figure out individual lines of code during the lessons to get them to stretch their minds, rather than play it safe by simply copying my instructions. I am really enjoying doing your course and wish you had been one of my professors when I learned this in college. Thanks again! I am going to do your Raspberry Pi and other videos as well!

[mse]

Thank you for everything you've taught me in these lessons. I was able to make the calculator beforehand, and after some troubleshooting and a headache, I was able to get it to work and come see how you've done it.

[gunjanlakhlani]

Sir, I have a PhD in astrophysics and I recently bought an arduino to play with. Your videos are awesome and you are a great teacher! I really really hope you get many many more subscribers. My best wishes to you! Thank you so much for sharing your knowledge with the world.

[ricardocarmona]

This homework took me a while to do, I got really frustrated when making a skeleton for the code (using the serial monitor rather then the LCD display) until I realized my monitor was set to no new line ending for some reason. Even though I found that mistake 2 days later (took a day break for a birthday) and I completed the rest of the project! I came across many mistakes in my code and I just want to thank you Pual for giving me the motivation to keep on trying over and over again! Also count me in for an A+ I made sure to make my numbers float rather then integers after I realized we needed to divide. Thank you again Grandpa!

[MrJohnjamesboyd]

Hi Paul, I pulled my hair out over this one but found that to make my code work I had to set the serial monitor to “No line Ending”. Thanks again for your great tutorials.

[johnvandenberg]

I built it Paul and it worked perfectly. I feel like a young Engineering undergraduate plus 30 years. Thank you so much .

[lesliefoster]

Thank you for doing these lessons. Doing them line by line and showing mistakes is so helpful, making them the best Arduino lessons on YouTube.

[pratyushmisra]

THANK U SO MUCH SIR FOR HELPING ME LEARN

[danielsaenz]

I did the Homework!!!! Thanks, SOOO much Paul, we are very blessed to have you as our teacher

[tonygolden]

Thanks again Paul for a great lesson. As Milton wrote in sonnet 19, “They also serve who only stand and wait”. We must remember to thank those while statements.

[FF]

125 lines later.. it took about an hour but I got it!! Boy am I glad that I take notes each lesson. I got it right the first time, with the exception of forgetting to turn on the serial monitor which I quickly realized after seeing a 0 pop up for the answer! Thanks for being an incredible teacher Paul!

[TheScissorunner]

I used to be a bit intimidated by the homework... not anymore! My confidence grows with each tutorial and I can now say "bring it on!" because I can do this!

Breezed through this one and when I did hit a snag or two was able to debug and get things running in short order. Now I look forward to seeing how you will do this and compare.

Can't give you enough thanks Mr. McWhorter, you helped get me down the path of knowledge.

[pokerface]

OK This homework assignment stumped me for a while, I almost gave up and watched the video, but at the last moment I decided to start fresh. I realized pretty quickly that I was trying to sever myself from the computer too fast, and that I would need the serial monitor to get my inputs (I was previously trying to do it all through the LCD display). Once I incorporated the serial monitor, the rest flowed together pretty naturally! I am happy to report that I set up my first and second inputs as floats, and the calculator worked pretty well on the first try. My code was very similar to yours (with the exception of some variable names and formatting) but I think you would have been happy with my answer(e). Thank you for this!

[ricklawitzky]

Fabulous video and explainment! English may not be my mother tongue, but I fully understand you explaining and showing me the world of Arduino! It is a great talent of you to make people understand stuff. Btw: Thank you for making such lessons available for everyone without demanding money!

[metoliusdad]

It's always wonderful to find someone who has found and follows their calling...