SDEX2M2 (MicroSD Express to M2) is an adapter for the Nintendo Switch 2 which converts the MicroSD Express slot to a NVME M.2 (M-Key) slot. Think MicroSD Express cards are difficult to find or expensive? Looking to expand your storage for cheaper? Just use the NVME M.2 SSD that you have, and/or can easily find! The project is open source hardware under the GPLv3 License.
This project also encompasses the sister-project of "MicroSD Express to SD Express" adapter, which is a pin-to-pin conversion kit allowing full size SD Express cards to be used on the Nintendo Switch 2.
- Introduction
- Assets & Hardware Info
- PCB's / Boards
- License
This is possible because the Nintendo Switch 2's MicroSD Express slot supports the SD Express 7.1 standard, which exposes a true PCIe Gen3 x1 interface and utilizes the NVMe protocol for communication.
This adapter simply maps PCIe x1 from the Switch 2’s MicroSD Express slot to a standard M.2 2230 NVMe SSD. After further research and review from users, an onboard mcu/fpga will be required for the handshake provess with the Switch 2.
- ✅ Create Pinout & Pin Definitions (UPDATED!)
- ✅ Create Footprints for MicroSD Express
- ✅ Create Schematic for PCB layout
- ✅ Create Dummy MicroSD Express Card V2
- ✅ Create M.2 Breakout for prototyping (Updated 2-layer PCB)
- ✅ Create MicroSD Express Breakout Board V0.1 (Updated 2-layer PCB)
- ✅ Create MicroSD Express to SD Express Adapter (Experimental, Updated 2-layer PCB)
- ✅ Create BOM for fabrication and sourcing (WIP)
- ✅ Create MicroSD Express to NVMe M.2 SSD Pin to Pin Adapter (Proof of concept)
- 🔲 Create MicroSD Express to NVMe M.2 SSD Adapter with FPGA/MCU Proto (for handshake with Nintendo Switch 2)
- 🔲 Create MicroSD Express to NVMe M.2 SSD Dock/Flex Cable Setup
Work in progress.
Currently, an early proof of concept prototype of the SDEX2M2 MicroSD Express to NVMe M.2 SSD Adapter has been made.
Additionally, production-ready (hopefully!) 2-layer PCBs for the MicroSD Express breakout board, and the NVMe breakout board have been uploaded.
The MicroSD Express to SD Express (full size) adapter production ready board has been uploaded too.
- Use at your own risk. We are not liable for any damage to your drive, Switch 2, or other devices.
- Only use low-voltage, low-power M.2 2230 NVMe drives.
- Do not use this in legacy MicroSD slots (e.g., original Nintendo Switch).
| Reference | Quantity | Description | Part Number | Manufacturer |
|---|---|---|---|---|
| J2 | 1 | M.2 Socket (M-Key, 2230) | 114020 | Amphenol |
| FB1 | 1 | Ferrite Bead 220Ω@100MHz 0603 | BLM18PG221SN1D | Murata/OEM |
| PCB | 1 | 4-Layer PCB | N/A | Fabricated |
| * | 1 | 10kΩ – 100kΩ Pull Up Resistor (Optional) | N/A | * |
The optional resistor is for the PERST# lane, may help with state when idle. Not sure if needed until prototyping commences.
| microSD Express Pin | PCIe Function | M.2 M-Key Pin(s) | M.2 Function |
|---|---|---|---|
| 7 (Row 1) | REFCLK+ | B10 | REFCLK+ |
| 8 (Row 1) | REFCLK− | B11 | REFCLK− |
| 2 (Row 1) | PERST# | A11 | PERST# |
| 1 (Row 1) | CLKREQ# | B8 | CLKREQ# |
| 11 (Row 2) | TX+ | B23 | PCIe TX+ |
| 12 (Row 2) | TX− | B24 | PCIe TX− |
| 14 (Row 2) | RX- | A21 | PCIe RX+ |
| 15 (Row 2) | RX+ | A22 | PCIe RX− |
| 4 (Row 1) | 3.3V VDD | B2, B3, B4 | 3.3V Power |
| 6, 10, 13, 16 | GND | A1, A4, etc. | Ground |
| Pin | Name | Function |
|---|---|---|
| A11 | PERST# | PCIe Reset |
| A21 | RX+ | PCIe RX+ (to host) |
| A22 | RX− | PCIe RX− (to host) |
| B10 | REFCLK+ | PCIe Reference Clock + |
| B11 | REFCLK− | PCIe Reference Clock − |
| B23 | TX+ | PCIe TX+ (from host) |
| B24 | TX− | PCIe TX− (from host) |
| B2–B4 | 3.3V | Power Supply |
| A1, A4 | GND | Ground Pins |
In SD Mode &* PCIe Mode
| Pin | Row 1 Contact | SD Mode Function | PCIe Mode Function |
|---|---|---|---|
| 1 | DAT2 | Data Line 2 | CLKREQ# (Power / Signal Mgmt) |
| 2 | DAT3 / CD | Data Line 3 / CD | PERST# (Reset) |
| 3 | CMD | Command Line | CMD (unused in PCIe mode) |
| 4 | VDD | 3.3V Power | 3.3V Power |
| 5 | CLK | Clock Line | CLK (unused in PCIe mode) |
| 6 | VSS | Ground | Ground |
| 7 | DAT0 | Data Line 0 | REFCLK+ (PCIe Ref Clock) |
| 8 | DAT1 | Data Line 1 | REFCLK− (PCIe Ref Clock) |
| Pin | Row 2 Contact | PCIe Function |
|---|---|---|
| 9 | 1V8 | 1.8 Volts |
| 10 | VSS2 | Ground for isolation |
| 11 | TX+ | PCIe TX+ (Transmit) |
| 12 | TX- | PCIe TX- (Transmit) |
| 13 | VSS3 | Ground for isolation |
| 14 | RX- | PCIe RX- (Receive) |
| 15 | RX+ | PCIe RX+ (Receive) |
| 16 | VSS4 | Ground for isolation |
| 17 | 1V2 | 1.2 Volts |
Please note: Row 2 is only operational in PCIe Mode. Row 2 is based on M1cha's (https://github.com/M1cha/sdexpress_pcbs) schematic.
| MicroSD Express Pin | Function (PCIe Mode) | SD Express Slot Pin | Function in Slot |
|---|---|---|---|
| 1 DAT2 | CLKREQ# | 51 | CLKREQ# (Power / Signal Mgmt) |
| 2 DAT3 / CD | PERST# | 52 | PERST# (Reset line) |
| 3 CMD | CMD (unused) | — | CMD (unused in PCIe mode) |
| 4 VDD | 3.3V VDD | 18, 48 | VDD |
| 5 CLK | CLK (unused) | — | — |
| 6 VSS | GND (VSS1) | 17, 47, 49, 50 | GND |
| 7 DAT0 | REFCLK+ | 45 | REFCLK+ |
| 8 DAT1 | REFCLK− | 46 | REFCLK− |
| 9 1V8 | 1.8V VDD (VDD2) | 1, 2, 3 (often shared) | VDD 1.8 Volts |
| 10 VSS2 | GND (VSS2) | 17, 47, etc. | GND (GND Ground for isolation) |
| 11 TX+ | TX+ | 39 | PCIe TX+ (Transmit) |
| 12 TX- | TX− | 41 | PCIe TX- (Transmit) |
| 13 VSS3 | GND (VSS3) | 17, 47, etc. | GND (Ground for isolation) |
| 14 RX- | RX− | 35 | PCIe RX- (Receive) |
| 15 RX+ | RX+ | 37 | PCIe RX+ (Receive) |
| 16 VSS4 | GND (VSS4) | 17, 47, etc. | GND (Ground for isolation) |
| 17 1V2 | 1.2V VDD (VDD3, optional) | — | Not used (May be unused) |
Note: WIP
Still a WIP. Some discrepencies may exist.
A dummy card has been created (thanks to M1cha's design examples!), for reference. Files have been attached.
A production-ready 2-layer breakout board for MicroSD Express has been created (codenamed: "The Key"). Files have been attached in the repo. The purpose of this is for prototyping with a breadboard.
A breakout board for a NVMe M.2 SSD slot (M-key) has been created. Files have been attached in the repo. The purpose of this is for prototyping with a breadboard.
An extremely experimental production ready MicroSD Express to Full Size SD Express Slot adapter has been made. The purpose of this is to allow full size SD Express cards to be inserted into the Nintendo Switch 2.
Please be aware that it is untested as of the time of writing.
A production-ready (but experimental) 2-layer PCB for the SDEX2M2 MicroSD Express to NVMe M.2 adapter has been uploaded.
Please note that this is a pin-to-pin adapter, and is not capable of completing the handshake with Nintendo Switch 2. It is for proof of concept, and is untested as of the time of writing.
This hardware design is licensed under the CERN Open Hardware License Version 2 – Strongly Reciprocal (CERN-OHL-S v2).
The software/firmware design is licensed under the GNU General Public License v3.0 (GPLv3)
The documentation and readme is licensed under the Creative Commons Attribution-ShareAlike 4.0 International (CC-BY-SA 4.0).
See LICENSE, LICENSE-HARDWARE.txt and LICENSE-DOCUMENTATION for more information.