# M5Stack Unit Encoder (U135)

> M5Stack U135 Unit Encoder: an I2C rotary encoder unit — 30-position pulse knob (30 pulses per turn) with push button and 2× SK6812 RGB LEDs, read by an on-board STM32F030 that reports the accumulated count over I2C (0x40) on an HY2.0-4P Grove port; 5 V at 17 mA, 32 × 24 × 25.4 mm, 7.4 g.

- Manufacturer: M5Stack
- Part number: U135
- Category: Encoders
- Canonical page: https://www.xirkit.io/products/m5stack-unit-encoder-u135-e63f
- Pinout: https://www.xirkit.io/products/m5stack-unit-encoder-u135-e63f/pinout
- Structured JSON: https://www.xirkit.io/products/m5stack-unit-encoder-u135-e63f/data.json
- Source: Xirkit structured parts catalog — every value traced to a cited document; unknowns are explicit.

## Key specifications

| Property | Value |
| --- | --- |
| Sensing | mechanical |
| Type | incremental |
| Resolution (PPR) | 30 PPR |
| Channels | decoded on board (count over I2C) |
| Interface | i2c |
| Output | I2C count + button state (address 0x40) |
| Index channel | no |
| Supply voltage | 5–5 V |
| Dimensions | 32 × 24 × 25.4 mm |

## Pinout (4 pins, 0 with electrical limits)

| Pin | Position | Kind | Chip pad | Functions | VIH | VIL | VOH | VOL | IOH | IOL | 5 V tolerant |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| GND | HY2.0-4P (Grove) · PORT.A-1 | ground | — | ground | — | — | — | — | — | — | — |
| 5V | HY2.0-4P (Grove) · PORT.A-2 | power in | — | power_in | — | — | — | — | — | — | — |
| SDA | HY2.0-4P (Grove) · PORT.A-3 | data | — | sda | — | — | — | — | — | — | — |
| SCL | HY2.0-4P (Grove) · PORT.A-4 | clock | — | scl | — | — | — | — | — | — | — |

## Where to buy

| Supplier | Price | Stock | Checked | URL |
| --- | --- | --- | --- | --- |
| shop.m5stack.com | 7.95 USD | in_stock | 2026-10-01 | https://shop.m5stack.com/products/encoder-unit |

## FAQ

**What voltage powers the M5Stack Unit Encoder (U135)?**

Supply range 5–5 V.

**How much does the M5Stack Unit Encoder (U135) cost?**

From $7.95 at shop.m5stack.com. Prices are observed unit prices before tax and shipping.

**What are the M5Stack Unit Encoder (U135) dimensions?**

32 × 24 × 25.4 mm. A STEP model is available for enclosure fit checks.

**Where does this M5Stack Unit Encoder (U135) 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

- [M5Stack Unit Encoder (U135) datasheet](https://shop.m5stack.com/products/encoder-unit)
- [shop.m5stack.com listing](https://shop.m5stack.com/products/encoder-unit)