Using Keypads with Arduino - Build an Electronic Lock

Today we are going to work with Matrix Keypads, easy-to-use interfaces for your Arduino designs. We’ll also build an electronic combination lock.

I’m sure you’ve seen lots of devices that use keypads, they are a common user interface for many types of electronic equipment that require user input.

Membrane matrix keypads are very inexpensive and, as it turns out, they are also very easy to use with an Arduino. This makes them an ideal input device for your next project.

Today I’ll show you how these devices work and how simple it is to use them. We’ll start with the basics and finish by constructing an electronic combination lock.

Here is what will be covered in this video:

00:00 - Introduction
02:12 - How Keypads work
06:18 - Basic Keypad test
12:37 - Keypad with LCD
18:39 - Electronic Lock

As always, you’ll find an article that has more details and all of the code used in this video on the DroneBot Workshop website.

Hope you enjoy the video!

[Webendowed]

I'm fairly new to the electronic hobby. I bought my UNO R3 kit and a 37 piece sensor kit as a Christmas present to myself, so I'm only around 5-6 months into this journey but you have taught me so much. I just wanted to drop you a comment and say thank you for making quality and informative videos. :)

[mattikaki]

I have been doing electronics from 1966 as a ham operator and from 1969 as electronic maintenance engineer. Now I am retired and have been ignoring Arduino until now when I need a matrix keyboard electronics. Thank you for very clear tutorial.

[chetanreddy]

I watch whole ads without skipping only for his effort! Its easily understandable even by beginners.

[ramakrishnatadepalli]

I am a 12 year child and I was very interested in electronics I got my first arduino it was very important for me to understand as I had no idea this channel is so helpful that I understand it so easily thanks

[peterpade]

I’m a retired mechanical engineer from Sydney, Australia. Just recently started dabbling into electronics and found your guidance extremely helpful. Thanks for your very helpful projects.

[abenwinUT]

For us noobies.... this is a very informational video. Thanks for the time taken to produce this video. Learned a lot already. Just wanted to share something that was a mystery to me until I found it on Amazon. And that is the LCD address. Default Address: 0x27 for PCF8574T chip; 0x3F for PCF8574AT chip;. Mine has the PCF8574T chip, hence 0x27. No wonder it didn't work when I had 0x3f. Thanks again for all who share their experience with us 'noobies'.

[bluegizmo]

Years ago, I had a car with a broken ignition key lock, so it could be started with any key. Rather that replace the ignition key lock I installed a hidden matrix keypad that acted as a starter bypass system so the car couldn't be started unless you entered the code on the hidden keypad first. Yes, it would've been easier to just replace the ignition key, but it was way cooler to have a hidden keypad to start the car lol

[hc]

this is the best one out there. He explains how library ref works and why he chose to wrote the code in such a way. The others just make a 3-5 min video and then spent half of it showing now to solder.

[electronic]

It was a useful and educational video. I watched every second with pleasure.

[carlgradolph]

Thanks for producing an easy-to-follow introduction to matrix keypads. The combination lock project nicely illustrates how data entered on a keypad can be used to make something happen. I can imagine a number of useful ways to expand the sketch.

[robertb]

Kudos to this channel for finally ditching the two camera setup during the show. Now the show can get it's 5 star rating it deserves.

[FoxAndHenForge]

Thank you! I was having issues with entering multiple digits in a row but you answered all my questions there!

[fury]

How people gives thumbs down? As long as people give effort you should appreciate it, especially for this kind of project. Look how he present and Explained it well ⚡ Be kind, spread love

[u-bloxi-parry]

Could you please do something for the upcycleing and reusing of salvaged keypads/lcd displays/rotary encoders, ANYTHING that you can salvage from electronics, please??

[monkeymanstones]

Adsense owes you for 2 commercials I watched before the video started.
Thanks for making this video. I can now use my large number of these 16 button pads I recieved with my many Gizmosphere Gizmo 2's.
What I'd love is a video showing how to use the pad, 4 or so air quality sensors and a (I think it's a DHT11) Temp & Humidity sensors to be able to have the display switch between the sensors based on the button I press on these keypads.
Thanks again for this video!

[Coolarj]

You are amazing - your videos are SO good!! Each and every one of them is pleasant to watch/listen to, clear, detailed, and very step-by-step with no missed steps in between! Thank you!!

[dalek]

Thank you for the instructional video. You saved me from purchasing a computer manufacturer's $25 keypad which is more or less the same thing as a $3.99 one.

[tubeDude]

As always, *GREAT* *JOB Bill* !! For those that don't know, you might have explained the 2 jumpers on the I2C module and the one on the Relay.

[MrWATCHthisWAY]

Love your channel, your work shop, each lessons and the fact that you teach everyone who knows little to absolutely nothing about electronics & electricity. Your explanations and real world applications make your lessons even more useful and enjoyable to your audience. I too use the female to male Ribbon Cables to make connections in the same fashion as you do, but I’ve found that cheap ones have minimal contact on their respective sides and have caused more problems and made bad connection when using them. I only purchase quality ribbon cables from now on because of these problems created. You mentioned that we could use any pin for signaling the Solenoid controller and you chose pin 13. I’m guessing any pin that is still non-designated unless we rewrote the software code to allow for double usage! I’m fairly new to code writing as you can read from my question. Have a long history with electronics & electricity but interfacing the coding is still a challenge for me. But with your tutorial I’m moving at a faster pace now and for this I thank you for all that you make available to us. Great job and I’m constantly going back over and rewatching all your tutorials. If only my workbench and area look like yours? To have power coming from a outlet on the back face of your workbench. Now that would be something, and maybe you could show us how you developed your workstation? It truly is something to be proud of!!! Love you work and never miss any or your video’s because there is always something new to learn even though I’ve been at this for awhile!!!

[NortelGeek]

ABCD are part of the AUTOVON military telephone network. It's still there but no longer used very much. ABC and D were usually marked as "Routine, Priority, Flash, and Flash Override", each creating a "precedence" for the call going through. Flash Override was the highest priority call and each of these classifications could "preempt" other lower priority calls on the public network during a disaster or other emergency.

For the youngsters: Flash wasn't always used for just three-way calls. It was originally used to signal or "recall" the operator after a call to arrange payment for overtime usage or to set up repeat dialing or "sequence calls" which are calls that could be made after the current one without hanging up. After that, Flash (or "Link" on Nortel phones) was used to invoke other automated features, such as conference calling, call waiting and call parking.