Rpi Zero M.2 E Key Shield

This is a mount for an 2230 or 2242 M.2 E-key Wifi card sized to be a back-side shield for a Raspberry Pi Zero 2.

This PCB takes in 2-6S voltage on the main 6-pin connector to provide power for the card and the Pi-Zero. Communication with the host computer is through USB.

USB from the M.2 card is exposed for any device through the mounted USB-C connector, the bottom 4-pin JST-GH, or through the pads on the bottom.

The pads on the bottom are positioned to allow for spring loaded pogo pins to align to matching pads on the bottom of a Pi-Zero 2. This board is then mounted back-to-back on the Pi-Zero to save space and reduce wires.

Product Specs

1. M.2 Mount: E-Key
2. M.2 Protocol: USB
3. Input voltage: 2-6S
4. 3.3V Maximum Current: 8A
5. 5V Maximum Current: 3A
6. Size: 65mm by 30mm
7. Weight: 7.65g
8. Mounting Pattern: Raspberry Pi Zero 2 Hole Pattern

Notes

1. Only breaks out the USB lines for the M.2 E-Key for communications, no SDIO, I2C, or UART. Maybe in a future Rev.
2. Only connect over USB to one device at a time. Even though there are 3 possible ways to get to USB, they all go to the same place on the M.2.
3. Wifi devices at this size tend to get hot. The height of the card from the pcb is designed to allow users to put a thermal interface material between them, or a 3rd party heatsink that wraps around the card.
4. This provides 5V to the USB connectors to power the parent Raspberry Pi Zero or similar. If you wish to disable this regulator, close the unpopulated pads on the right side of the 6-pin JST input connector with a 0-ohm resistor or solder bridge.
5. High in-rush voltage can damage this board. Current boards ship with a manually added diode to clamp voltage spikes, and future revisions will improve on this.