# Adafruit Metro (Uno form factor), Metro Mini and Grand Central (Mega form factor)

> Is the Adafruit Metro the same size as an Arduino Uno?

- Category: Electronics › Microcontroller boards
- Kind: Modern device
- Basis: Adafruit CAD (MIT); Metro follows the Arduino Uno outline and hole pattern, Grand Central the Mega outline
- Page: https://xemstudio.com/objects/adafruit-metro-grand-central/ · JSON: https://xemstudio.com/api/geometry?object=adafruit-metro-grand-central · Plain text: https://xemstudio.com/objects/adafruit-metro-grand-central/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

## Notes

- Metro (328, M4, ESP32-S2, RP2350): 68.6 × 53.3 mm with the Uno's four holes (14.0/15.2 and 66.0 from the USB-end edge), USB at the left end, barrel jack beside it; shields fit.
- Grand Central M4: 101.5 × 53.3 mm, the Mega 2560 outline and holes. Metro Mini: 44.5 × 17.8 mm, breadboard-friendly, no holes.
- Metro boards use a micro-B or USB-C where the Uno has USB-B; the port position is the same, the cutout smaller.

## Sizes

| product | bbox_l_mm | bbox_w_mm | bbox_h_mm |
|---|---|---|---|
| 3382 Metro M4 | 71.9 | 53.3 | 14.5 |
| 2488 Adafruit Metro 328 | 71.1 | 53.3 | 12.1 |
| 2590 Metro Mini | 43.8 | 17.8 | 4.3 |
| 4775 Metro ESP32-S2 | 71.9 | 54.6 | 16.9 |
| 6003 Metro RP2350 | 71.8 | 54.3 | 14.5 |
| 4064 Grand Central M4 | 104.9 | 53.4 | 14.5 |

## Where the files are

- Adafruit (official): [Adafruit_CAD_Parts: STEP, Fusion 360 and STL for Adafruit products](https://github.com/adafruit/Adafruit_CAD_Parts) — STEP, F3D, STL — MIT

## Free STEP/STL (6 parts, MIT License (Adafruit_CAD_Parts), Adafruit Industries)

Index: https://xemstudio.com/files/adafruit/adafruit-metro-grand-central/index.json

- 3382-metro-m4: [STEP](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/3382%20Metro%20M4/3382%20Metro%20M4.step) · [STL](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/3382%20Metro%20M4/3382%20Metro%20M4.stl) — Adafruit #3382 Metro M4; bbox 71.9 × 53.3 × 14.5 mm; 4.3 MB on GitHub
- 2488-adafruit-metro-328: [STEP](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/2488%20Adafruit%20Metro%20328/2488%20Adafruit%20Metro%20328.step) — Adafruit #2488 Adafruit Metro 328; bbox 71.1 × 53.3 × 12.1 mm; 0.1 MB on GitHub
- 2590-metro-mini: [STEP](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/2590%20Metro%20Mini/2590%20Metro%20Mini%20Rev%20B.step) · [STL](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/2590%20Metro%20Mini/2590%20Metro%20Mini%20Rev%20B.stl) — Adafruit #2590 Metro Mini; bbox 43.8 × 17.8 × 4.3 mm; 2.5 MB on GitHub
- 4775-metro-esp32-s2: [STEP](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/4775%20Metro%20ESP32-S2/4775%20Metro%20ESP32-S2.step) · [STL](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/4775%20Metro%20ESP32-S2/4775%20Metro%20ESP32-S2.stl) — Adafruit #4775 Metro ESP32-S2; bbox 71.9 × 54.6 × 16.9 mm; 3.6 MB on GitHub
- 6003-metro-rp2350: [STEP](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/6003%20Metro%20RP2350/6003%20Metro%20RP2350.step) — Adafruit #6003 Metro RP2350; bbox 71.8 × 54.3 × 14.5 mm; 6.1 MB on GitHub
- 4064-grand-central-m4: [STEP](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/4064%20Grand%20Central%20M4/4064%20Grand%20Central%20M4.step) · [STL](https://raw.githubusercontent.com/adafruit/Adafruit_CAD_Parts/main/4064%20Grand%20Central%20M4/4064%20Grand%20Central%20M4.stl) — Adafruit #4064 Grand Central M4; bbox 104.9 × 53.4 × 14.5 mm; 6.4 MB on GitHub

## Questions

**Do Arduino Uno cases fit the Adafruit Metro?**

Yes for the outline and mounting holes; the USB cutout differs (micro-B/USB-C on Metro vs USB-B on Uno), so the end panel needs a different opening.

**What are Grand Central M4 dimensions?**

101.5 × 53.3 mm, the Arduino Mega outline and hole pattern, USB-C, microSD on the underside.

## Fits with

- [Arduino Uno R3](https://xemstudio.com/objects/arduino-uno-r3/)
- [Arduino Mega 2560 R3](https://xemstudio.com/objects/arduino-mega-2560/)
- [Adafruit Feather boards and FeatherWings](https://xemstudio.com/objects/adafruit-feather-boards/)
- [Threaded standoffs, M2.5 and M3 (hex and round)](https://xemstudio.com/objects/threaded-standoffs-metric/)