# Adafruit MPR121 Gator Capacitive Touch

> Adafruit 4830 MPR121 Gator: 12-channel capacitive touch breakout with large alligator-clip-friendly pads and STEMMA QT — clip any conductive object (fruit, foil, wire) to a pad, no soldering. NXP MPR121 reports touch / release over I2C (0x5A, 0x5B with the addr jumper — 24 pads on one bus), 3–5 V supply and logic, 51 × 25.2 × 4.5 mm.

- Manufacturer: Adafruit Industries
- Part number: 4830
- Category: Tactile & touch sensors
- Canonical page: https://www.xirkit.io/products/adafruit-mpr121-gator-capacitive-touch-52df
- Pinout: https://www.xirkit.io/products/adafruit-mpr121-gator-capacitive-touch-52df/pinout
- Structured JSON: https://www.xirkit.io/products/adafruit-mpr121-gator-capacitive-touch-52df/data.json
- Source: Xirkit structured parts catalog — every value traced to a cited document; unknowns are explicit.

## Key specifications

| Property | Value |
| --- | --- |
| Sensing | capacitive |
| Active area shape | electrodes |
| Touch channels | 12 |
| Output | touch / release status per electrode over I2C |
| Interface | i2c |
| Supply voltage | 3–5 V |
| Dimensions | 51 × 25.2 × 4.5 mm |

## Pinout (5 pins, 0 with electrical limits)

| Pin | Position | Kind | Chip pad | Functions | VIH | VIL | VOH | VOL | IOH | IOL | 5 V tolerant |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Vin | — | power in | — | power_in | — | — | — | — | — | — | — |
| GND | — | ground | — | ground | — | — | — | — | — | — | — |
| SCL | — | i2c scl | — | scl | — | — | — | — | — | — | — |
| SDA | — | i2c sda | — | sda | — | — | — | — | — | — | — |
| addr | — | address | — | addr | — | — | — | — | — | — | — |

## Where to buy

| Supplier | Price | Stock | Checked | URL |
| --- | --- | --- | --- | --- |
| www.adafruit.com | 6.95 USD | in_stock | 2026-10-01 | https://www.adafruit.com/product/4830 |

## FAQ

**What voltage powers the Adafruit MPR121 Gator Capacitive Touch?**

Supply range 3–5 V.

**How much does the Adafruit MPR121 Gator Capacitive Touch cost?**

From $6.95 at www.adafruit.com. Prices are observed unit prices before tax and shipping.

**What are the Adafruit MPR121 Gator Capacitive Touch dimensions?**

51 × 25.2 × 4.5 mm. A STEP model is available for enclosure fit checks.

**Where does this Adafruit MPR121 Gator Capacitive Touch data come from?**

Every value in this record is traced to a source — 2 documents including the board and chip datasheets — with the page and table cited per value. Unknowns are left explicit, never guessed.

## Sources

- [Adafruit MPR121 Gator Capacitive Touch datasheet](https://cdn-learn.adafruit.com/downloads/pdf/adafruit-mpr121-gator.pdf)
- [www.adafruit.com listing](https://www.adafruit.com/product/4830)

## Part graph

### Built from

- MPR121 — sensor on the Adafruit MPR121 Gator 12-Key Capacitive Touch

### Alternatives (by use case)

- [Adafruit AT42QT1012 Capacitive Touch (toggle)](https://www.xirkit.io/products/adafruit-at42qt1012-capacitive-touch-toggle-8b03) — Both serve touch and force sensing — check the trade-offs; $5.95 vs $6.95
- [Alpha MF02A Square FSR 38 mm (1–49 N)](https://www.xirkit.io/products/alpha-mf02a-square-fsr-38-mm-1-49-n-09b0) — Both serve touch and force sensing — check the trade-offs; $6.95 vs $5.95
- [Alpha MF01A Round FSR 14.7 mm (0.3–10 N)](https://www.xirkit.io/products/alpha-mf01a-round-fsr-14-7-mm-0-3-10-n-22e6) — Both serve touch and force sensing — check the trade-offs; $6.95 vs $3.95
- [Interlink FSR 402 Round FSR 12.7 mm](https://www.xirkit.io/products/interlink-fsr-402-round-fsr-12-7-mm-3272) — Both serve touch and force sensing — check the trade-offs; $6.95 vs $10.95
- [Interlink FSR 400 Small Round FSR 5 mm](https://www.xirkit.io/products/interlink-fsr-400-small-round-fsr-5-mm-9120) — Both serve touch and force sensing — check the trade-offs; $6.95 vs $10.95
- [Adafruit MPR121 12-Key Capacitive Touch](https://www.xirkit.io/products/adafruit-mpr121-12-key-capacitive-touch-b241) — Both serve touch and force sensing — check the trade-offs; $6.95 vs $7.95
- [Adafruit AT42QT1010 Capacitive Touch (momentary)](https://www.xirkit.io/products/adafruit-at42qt1010-capacitive-touch-momentary-ba53) — Both serve touch and force sensing — check the trade-offs; $6.95 vs $5.95