Welcome to my little weekend project.

In this guide, I'll show you how I built a Sign Language Recognition Glove using nothing more than an Arduino Nano, a handful of flex sensors, an LCD display and... a lot of soldering patience.

The idea behind the project is simple.

When you bend a finger, the flex sensor changes its resistance. The Arduino continuously reads these values, recognizes predefined gestures, and displays the corresponding word on an LCD.

For my prototype, I mapped a few gestures like:

👍 Thumb → Hello

☝ Index → Food

🖕 Middle → Water

💍 Ring → Help

🤏 Little Finger → Thank You

Along with combinations like:

Thumb + Index → Yes

Thumb + Middle → No

All fingers → Emergency

Although this isn't a production-ready device, it demonstrates how simple electronics can be used to build accessible assistive technology.

Most importantly...

It's a really fun build.

Let's get started.

Hardware

1. Arduino Nano
2. 5 Flex Sensors
3. 16x2 LCD Display
4. I2C LCD Backpack
5. 5 × 10kΩ Resistors
6. Jumper Wires
7. USB Cable
8. 9V Battery (optional)
9. Battery Clip
10. Black Glove
11. Hot Glue Gun
12. Soldering Iron
13. Flux
14. Solder Wire
15. Helping Hands (Trust me...buy one.)

Software

1. Arduino IDE

Libraries

Whenever I start an electronics project, I never connect every component immediately.

Instead...

I test one component at a time.

This saves hours of debugging later. So we'll do exactly that.

The order we'll follow is :

Arduino Nano

↓

LCD

↓

One Flex Sensor

↓

Five Flex Sensors

↓

Complete Glove

It may seem slower...

It actually ends up being much faster.

First connect your Nano to your computer using a USB cable.

The power LED should immediately light up.

Open Arduino IDE.

Select

Choose the correct COM Port.

Now upload the Blink example.

If the tiny LED on the Nano starts blinking...

Congratulations!

Your Arduino is alive.

Mine passed this test immediately.

Small victory :D

Most inexpensive LCD modules come separately from the I2C Backpack.

Mine did too.

Which meant...

Time to solder.

Carefully solder every header pin.

Take your time here.

Good solder joints make life easy later.

Bad solder joints make you question your existence.

Once soldered...

Connect the LCD like this

LCD (I2C Backpack) -> Arduino Nano

Upload a simple Hello World sketch.

If nothing appears...

Don't panic.

Mine didn't either.

There's a tiny blue potentiometer on the I2C Backpack.

Use a screwdriver and slowly rotate it.

Eventually...

Hello World magically appears.

This was the part I found the coolest.

A flex sensor behaves like a resistor.

When straight...

Resistance is lower.

When bent...

Resistance increases.

Unfortunately...

The Arduino can't measure resistance directly.

So we build something called a Voltage Divider.

Don't worry.

It sounds scarier than it is.

The circuit looks like this

The Arduino simply measures the voltage at the middle point.

As the flex sensor bends...

That voltage changes.

Pretty neat.

Don't connect all five sensors immediately.

Connect one.

Seriously.

You'll thank yourself later.

Here's how mine was connected.

One end of the Flex Sensor

↓

GND

The other end

↓

Junction Point

↓

Arduino Analog Pin

↓

10kΩ Resistor

↓

5V

Once everything was connected...

I uploaded a tiny Arduino sketch to print the analog values.

Straight finger

Bent finger

Perfect.

Now we know everything works.

Only then...

Repeat the exact same wiring four more times.

Now repeat the exact wiring for every finger.

Each sensor needs

One Flex Sensor

One 10kΩ resistor

One Analog Pin

One shared 5V

One shared GND

Nothing more.

This was honestly the messiest part.

Hot glue became my best friend.

I glued each flex sensor carefully along the back of every finger.

The important part is making sure the sensing strip bends naturally when your finger bends.

Try keeping the wires running towards your wrist.

It makes cable management much easier later.

Although...

Mine still became spaghetti. 😂

Before writing any gesture recognition code, let's verify that every flex sensor is actually working.

Upload a simple sketch that prints the analog values to the Serial Monitor.

Open the Serial Monitor and slowly bend one finger at a time.

You should notice values changing as each sensor bends.

For example, my glove looked something like this:

When I bent a finger, only that sensor's value changed.

This is exactly what we want.

If one finger doesn't change:

1. Check the solder joints.
2. Check the resistor.
3. Check the analog pin connection.
4. Make sure the flex sensor isn't damaged.

This testing step saved me multiple hours of debugging later.

Here's something I learned the hard way...

Not all flex sensors behave the same.

One sensor might rest at 960, while another rests at 810.

That means using one fixed threshold for every finger usually doesn't work.

Instead, write down two values for each sensor:

1. Finger Straight
2. Finger Bent

For example:

These values will be different for your glove, and that's completely normal.

Calibration is one of the most important parts of any sensor-based project.

Now comes the fun part.

Instead of trying to recognize the entire sign language alphabet, I decided to create a small gesture vocabulary for the prototype.

This made the project much easier to demonstrate while still showing how the concept works.

Here's the gesture mapping I used:

You can, of course, customize these to anything you'd like.

During development, I powered everything directly through my MacBook using the Nano's USB port.

This made uploading new code and testing much easier.

For a standalone version, you can power the Nano using:

1. A 9V battery connected to VIN and GND, or
2. A rechargeable battery pack if you plan to wear the glove for longer periods.

For this prototype, USB power worked perfectly.

Every project teaches you something, and this one definitely did.

Some of the biggest challenges I ran into were:

1. Learning how voltage dividers actually work.
2. Soldering tiny flex sensor terminals without damaging them.
3. Creating 10kΩ resistors by combining smaller resistors because I didn't have enough 10kΩ ones lying around.
4. Debugging LCD issues caused by contrast settings.
5. Managing a glove full of wires without accidentally pulling something loose.
6. Calibrating five different flex sensors, each with slightly different readings.

Looking back, these challenges ended up teaching me far more than simply following a tutorial ever could.

This project is just Version 1.

There are plenty of ways it could be improved.

Some ideas I have are:

1. Train a Machine Learning model instead of using fixed thresholds.
2. Recognize the complete sign language alphabet.
3. Add Bluetooth or Wi-Fi to send messages directly to a phone.
4. Add text-to-speech so recognized gestures can be spoken aloud.
5. Build a companion mobile app.
6. Replace the wired setup with a rechargeable battery and a compact enclosure.
7. Use an IMU to recognize wrist movement and dynamic gestures.
8. Store personalized calibration profiles for different users.

I think this project has a lot of room to grow, and I'm excited to keep experimenting with it.

Some ideas I'm excited to explore are:

Machine Learning

Instead of manually setting thresholds, collect gesture data and train a model to recognize signs automatically.

Mobile App

Display recognized words directly on a phone using Bluetooth.

Speech Output

Convert recognized gestures into spoken words using a text-to-speech engine.

Complete Sign Language Recognition

Support the full alphabet along with dynamic gestures involving wrist movement.

Cloud Integration

Store gesture history or communicate with caregivers in real time.

AI Integration

Use lightweight on-device models for more accurate gesture recognition and user-specific calibration.

Finally, here's the complete Arduino sketch used for the prototype.

The code continuously reads all five flex sensors, determines which fingers are bent, and displays the corresponding word on the LCD. This is just a demo, you can tune it to perform in accordance to your goals with respect to translations.

Note: Every flex sensor behaves slightly differently. You may need to adjust the threshold values for your own glove after calibration.

If this is your first Arduino project, don't worry if things don't work perfectly the first time. Almost every issue I encountered came down to one of the following.

LCD only shows black boxes

Possible causes:

1. LCD contrast is not adjusted.
2. SDA and SCL wires are swapped or loose.
3. Wrong I2C address (0x27 vs 0x3F).
4. Missing LiquidCrystal_I2C library.

Solution

Adjust the small blue potentiometer on the I2C backpack while the LCD is powered.

LCD lights up but displays nothing

Check:

1. VCC connected to 5V.
2. GND connected correctly.
3. lcd.init();
4. lcd.backlight();

are present inside setup().

Sensor values never change

Possible reasons:

1. Wrong resistor connection.
2. Broken solder joint.
3. Flex sensor connected incorrectly.
4. Analog pin connected to the wrong Arduino pin.

Sensor always reads 1023

Usually indicates:

1. Open circuit
2. Broken flex sensor
3. Missing resistor

Sensor always reads 0

Usually indicates:

1. Short to Ground
2. Wiring mistake

Arduino Upload Failed

Things to check:

1. Correct Board selected.
2. Correct COM Port selected.
3. USB cable supports data transfer.
4. Close Serial Monitor before uploading.

LCD flickers constantly

Avoid calling

inside every loop.

Instead, only update the display when the detected word changes.

I started this project thinking it would mostly be about writing Arduino code.

It turned out to be much more than that.

Along the way I learned:

1. How analog sensors actually work.
2. What a voltage divider is.
3. Basic soldering techniques.
4. Reading sensor values from the Serial Monitor.
5. Debugging hardware one component at a time.
6. Calibrating sensors.
7. Why building hardware requires patience.

Perhaps the biggest lesson was this:

Don't connect everything at once.

Testing one component at a time made debugging incredibly easy.

Arduino.

↓

LCD.

↓

One flex sensor.

↓

Five flex sensors.

↓

Complete glove.

That simple workflow probably saved me several hours.

Why use flex sensors?

Because they're simple, inexpensive, and perfect for measuring finger bending.

Why Arduino Nano?

It's compact, beginner-friendly, inexpensive, and has enough analog pins for all five sensors.

Why an I2C LCD?

A normal LCD requires many wires.

The I2C backpack reduces this to just four.

Why not recognize actual sign language?

Real sign language involves:

1. Finger positions
2. Wrist orientation
3. Hand movement
4. Timing

This prototype focuses only on finger bending.

Think of it as the first building block rather than a complete interpreter.

Thank You :)

This project reminded me why I love engineering.

It's rarely a straight line from idea to finished product.

There are broken wires, bad solder joints, sensors that don't behave the way you expect, and plenty of moments where nothing seems to work.

But then, eventually, everything comes together.

Seeing the LCD display a word because of a gesture I made with my hand made all those little debugging sessions worth it.

I hope this guide helps you build your own version, or inspires you to take the idea even further.

If you do build one, I'd genuinely love to see it. Feel free to share your version or tag me so I can check it out.

Happy building! 🚀

If this guide helped you, consider:

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💬 Asking questions in the comments

🔧 Sharing your own version

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See you in the next build!

– Madhumitha Kolkar