Skip to main content
Home / Sensors / MPR121 Capacitive Touch Sensor Control Keyboard Development Board

Attributes

Brand -
Category Robotics / STEM Teaching Tools / Sensors
Origin -
Chip Model MPR121
Interface Protocol I2C (Inter-Integrated Circuit)
Input Channels 12 Capacitive Touch Electrodes
Operating Voltage 3.3V to 5.5V DC
Communication Address 0x5A (Default, configurable)
PCB Dimensions 24mm x 18mm
Connector Type 2.54mm Pitch Header Pins
Compatibility Arduino, Raspberry Pi, ESP32, STM32
Touch Sensitivity Adjustable via Software Registers
Package Includes 1x MPR121 Board, 1x Pin Header Strip

6 reviews

A

Anonymous

Mar 25, 2026

Rating: 5/5

Perfect for DIY Macro Pads

This board works flawlessly with my Arduino Pro Micro project. The I2C communication is stable, and the sensitivity adjustment allows me to detect touches even through a thin acrylic layer. Highly recommended for custom keyboard builds.

A

Anonymous

Mar 15, 2026

Rating: 4/5

Great value, needs careful wiring

The sensor itself is excellent and very responsive. I deducted one star because the pinout diagram on the back is slightly faint, so make sure you check the datasheet before soldering. Once connected, it worked immediately.

A

Anonymous

Mar 15, 2026

Rating: 5/5

Reliable for student projects

We bought ten of these for our robotics club. Students found the libraries easy to use, and the boards have survived multiple re-wiring sessions without any issues. Excellent durability for the price point.

A

Anonymous

Mar 13, 2026

Rating: 4/5

Good documentation support

The hardware is solid. I had some initial trouble with address conflicts when using two sensors, but the online community examples helped me resolve it quickly by changing the ADDR pin settings.

A

Anonymous

Mar 02, 2026

Rating: 5/5

Exceeded expectations

I was worried about noise interference, but the built-in filtering on the MPR121 chip handles it well. It detects gloved touches reliably, which was a specific requirement for my industrial control panel prototype.

A

Anonymous

Mar 01, 2026

Rating: 5/5

Low latency touch detection

Impressed by how fast the response time is. There is virtually no lag between touching the electrode and the signal being sent over I2C. Perfect for creating interactive art installations or musical instruments.

5 FAQ

Q: What is the maximum thickness of material that can cover the touch pads?

A: While dependent on sensitivity settings and material dielectric properties, the sensor typically works well through up to 3-5mm of plastic, glass, or wood. Calibration is recommended for thicker materials.

Q: Does this come with pre-soldered headers?

A: No, the board is shipped with a separate strip of header pins to allow you to choose the orientation (straight or right-angle) that best fits your project enclosure.

Q: Is there a library available for ESP32?

A: Yes, several open-source libraries are available on GitHub and the Arduino Library Manager that support the ESP32 platform. Search for 'MPR121' to find compatible options.

Q: How do I change the I2C address if I need to connect multiple boards?

A: You can change the I2C address by connecting the ADDR pin to VDD, GND, or SDA through specific resistors as detailed in the NXP MPR121 datasheet. This allows up to 4 devices on the same bus.

Q: Can this board be used directly with 5V logic without a level shifter?

A: Yes, the MPR121 module operates comfortably within the 3.3V to 5.5V range, making it directly compatible with 5V microcontrollers like the standard Arduino Uno.

Explore your interests

View More
All Categories
Best Seller (30)
New List (30)
Low-Temperature Plasma Oil Fume Purifier Electrostatic Ion Module Equipment Rubber Plastic Smoke Treatment Device

Low-Temperature Plasma Oil Fume Purifier Electrostatic Ion Module Equipment Rubber Plastic Smoke Treatment Device

$1,600.00

Chunfei Grocery Store - Yun'an GR02 Gravel Bike, Thru-Axle, Disc Brake, Lightweight Touring with Multiple Rack Mounts

Chunfei Grocery Store - Yun'an GR02 Gravel Bike, Thru-Axle, Disc Brake, Lightweight Touring with Multiple Rack Mounts

$7,977.00

Cashmir Blending Knife Replacement Head Set, Sketch Neony Blending Heads, Sponge Blending Heads, Breathing Cotton for Art Students

Cashmir Blending Knife Replacement Head Set, Sketch Neony Blending Heads, Sponge Blending Heads, Breathing Cotton for Art Students

$4.34

Natural Amethyst, Rose Quartz, Clear Quartz, and Lemon Quartz Double-Pointed Tumbled Beads for DIY Bracelets, Necklaces, and Earrings

Natural Amethyst, Rose Quartz, Clear Quartz, and Lemon Quartz Double-Pointed Tumbled Beads for DIY Bracelets, Necklaces, and Earrings

$1.70

Accordion-Style Watercolor Sketchbook, 32k Foldable Blank Paper, 300g Cotton Pulp Fine Texture for Painting, A4 Stamp Collection Travel Journal, DIY Sticker Art Notebook

Accordion-Style Watercolor Sketchbook, 32k Foldable Blank Paper, 300g Cotton Pulp Fine Texture for Painting, A4 Stamp Collection Travel Journal, DIY Sticker Art Notebook

$9.70

Electric Watercolor Spray Pen Children Hand-painted Color Pa

Electric Watercolor Spray Pen Children Hand-painted Color Pa

$52.55

VFD 2.2kW 9.8A Single Phase 220V

VFD 2.2kW 9.8A Single Phase 220V

$1,919.00

Printmaking Press Machine - Large Format Etching and Woodblock Printer for School Art Classes and Clubs

Printmaking Press Machine - Large Format Etching and Woodblock Printer for School Art Classes and Clubs

$583.11

Bread Rattle Superman Maraca Baby 0-1 Year Soothing Tool Newborn Safe to Chew Grip Training Hand Rattle

Bread Rattle Superman Maraca Baby 0-1 Year Soothing Tool Newborn Safe to Chew Grip Training Hand Rattle

$8.80

Direct Supply 0.75kw Laboratory Frame Mixer - Suitable for Mixing Fluid Materials, Adhesives, and Lithium Battery Applications

Direct Supply 0.75kw Laboratory Frame Mixer - Suitable for Mixing Fluid Materials, Adhesives, and Lithium Battery Applications

$2,395.00

Yonghe Hair Transplant Follicle Detection and Scalp Health Assessment - Consultation and Photodynamic Therapy Experience

Yonghe Hair Transplant Follicle Detection and Scalp Health Assessment - Consultation and Photodynamic Therapy Experience

$0.10

Continental CSC5 Tires – Sizes 215/225/235/245/255 x 40/45/50/55 R17/18/19/20/21

Continental CSC5 Tires – Sizes 215/225/235/245/255 x 40/45/50/55 R17/18/19/20/21

$725.00

Commercial High-Speed Fruit and Vegetable Crusher and Puree Maker, Continuous Processing Equipment for Galangal, Fresh Ginger, Bell Peppers, and Tomatoes

Commercial High-Speed Fruit and Vegetable Crusher and Puree Maker, Continuous Processing Equipment for Galangal, Fresh Ginger, Bell Peppers, and Tomatoes

$17,980.00

DIY Scented Candle Molds - 24 Popular Korean Acrylic PC Styles: Cylinder, Pointed Top, Flat Top, Square, Shell

DIY Scented Candle Molds - 24 Popular Korean Acrylic PC Styles: Cylinder, Pointed Top, Flat Top, Square, Shell

$10.80

Custom Solid Wood Plaque and Couplet Carving - Wooden Shop Signage, Arched Door Headers, and Grand Opening Engravings

Custom Solid Wood Plaque and Couplet Carving - Wooden Shop Signage, Arched Door Headers, and Grand Opening Engravings

$174.00

New Direct-Sale 326 Instant Glue - High-Strength Structural Adhesive for Metal, Heat Resistant, Anti-Aging, Ideal for Car Rearview Mirrors

New Direct-Sale 326 Instant Glue - High-Strength Structural Adhesive for Metal, Heat Resistant, Anti-Aging, Ideal for Car Rearview Mirrors

$26.54

Zhong Shaojing Lingfei Jing Small Regular Script Water Writing Cloth for Calligraphy Practice - Reusable Quick-Dry Mat

Zhong Shaojing Lingfei Jing Small Regular Script Water Writing Cloth for Calligraphy Practice - Reusable Quick-Dry Mat

$22.53

New 968 Fast-Drying Super Glue - Strong Bond for Metal, Magnets, Rubber, and Aluminum Alloy

New 968 Fast-Drying Super Glue - Strong Bond for Metal, Magnets, Rubber, and Aluminum Alloy

$18.20

German Imported Stone Removal Hook Car Tire Stone Cleaning Tool Vehicle Foldable Multi-Function Stone Remover

German Imported Stone Removal Hook Car Tire Stone Cleaning Tool Vehicle Foldable Multi-Function Stone Remover

$11.34

[10% Off for 2 Items] Double-Sided Wool Felt Mat for Calligraphy and Painting, Student Practice Sheet, Brush Writing Desk Pad, Four Treasures of the Study Set

[10% Off for 2 Items] Double-Sided Wool Felt Mat for Calligraphy and Painting, Student Practice Sheet, Brush Writing Desk Pad, Four Treasures of the Study Set

$6.63

In Stock Special Offer: QS18VP6LLPQ8 Sensor - Price Negotiable

In Stock Special Offer: QS18VP6LLPQ8 Sensor - Price Negotiable

$600.00

Broccoli Vegetable Washing Machine for Pre-made Dishes, Water Bath Cleaning Equipment with Bubble System for Herbs and Export-Grade Produce

Broccoli Vegetable Washing Machine for Pre-made Dishes, Water Bath Cleaning Equipment with Bubble System for Herbs and Export-Grade Produce

$615.00

Hongkedou Oxford Fabric Bag-in-Bag Divider Insert, Stiff Makeup Organizer with Zipper, Waterproof Small Women's Pouch

Hongkedou Oxford Fabric Bag-in-Bag Divider Insert, Stiff Makeup Organizer with Zipper, Waterproof Small Women's Pouch

$22.00

Pad Printing Machine Accessories: Positioning Clamps, T-Shaped Holders, and Locking Irons

Pad Printing Machine Accessories: Positioning Clamps, T-Shaped Holders, and Locking Irons

$0.60

Japanese High-Concentration Oxalic Acid Toilet Cleaner, Powerful Urine Scale Remover and Stain Eliminator

Japanese High-Concentration Oxalic Acid Toilet Cleaner, Powerful Urine Scale Remover and Stain Eliminator

$23.82

Biliansheng No-Shave Hair Transplant - Hairline and Crown Thinning Treatment, Hair Loss Detection Service

Biliansheng No-Shave Hair Transplant - Hairline and Crown Thinning Treatment, Hair Loss Detection Service

$86.00

Laorentou Paper Blending Stump for Sketching - Professional Art Supply for Highlighting and Pastel Work

Laorentou Paper Blending Stump for Sketching - Professional Art Supply for Highlighting and Pastel Work

$6.80

Fast-Drying Glue for ABS Plastic - Transparent, High-Strength, Odorless, Non-Whitening Instant Adhesive for ABS and PC Plastics

Fast-Drying Glue for ABS Plastic - Transparent, High-Strength, Odorless, Non-Whitening Instant Adhesive for ABS and PC Plastics

$58.96

Manufacturer Supply Oxygen Absorber Oxygen Generator Stable Performance Hydrogen-Rich Machine Hydrogen Generator

Manufacturer Supply Oxygen Absorber Oxygen Generator Stable Performance Hydrogen-Rich Machine Hydrogen Generator

$5,058.00

POPMART CRYBABY Vacation Mode On - Vinyl Plush Keychain Blind Box

POPMART CRYBABY Vacation Mode On - Vinyl Plush Keychain Blind Box

$106.99