This is an open-source universal mini-PCI-E breakout for all your MiniPCI-E needs. Whether you have a Pi4 that you think deserves a PCI-E slot, a 4G modem with cool functions on "RESERVED" mPCI-E pins, an SSD that you want to recover data from but lack the adapter (mSATA, EEE FLASH-CON or other), or maybe a small mPCIE WiFi card that you want to reuse or reverse-engineer, this board is for you. The KiCad files are available below!

Changes in v2:

• SIM slot pinout has been fixed - now it's an option enabled by default and not costing anything extra to the user.
• Added 1117 regulator footprints for 3.3V and 1.5V lines
• Made PCB mounting holes M3 and M4 instead of random diameters, spaced them apart in a way that made more sense. Also, adjusted spacer soldering holes so that it's easy to solder spacers to them.
• Changed 0R resistors to 0603 - allowing easier handsoldering of the bottom side and making production easier&cheaper, as I'd only need to solder the bottom layer parts if 1.5V or 3.3V LDO options are picked. This also makes the board lay flush with the desk if the 3.3V LDO is not soldered on - as it's a popular option, I'll likely move it to the top layer in the next revision.
• Made mPCIe socket alignment pin holes smaller so that they can actually help with alignment - making the mPCIe socket sit straight (as opposed to "liminally rotated") on the board.

Features:

• All mPCI-E pins broken out, even the "reserved" ones
• A MicroUSB socket for the USB-connected cards (+ pin header with all connections)
• A MicroSIM socket for all your GSM needs (+ pin header with all connections)
• Full MiniPCI-E pinout on the bottom silkscreen
• mSATA pinout mapping on the top silkscreen
• Eco-friendly (part of the mPCI-E sockets and most of the screw posts are harvested from old laptops)
• Screw posts for either full-size or half-size cards - screws included, too!

Useful for:

• Your own mPCI-E card development
• mPCI-E form-factor Arduino and MicroPython boards, like Arduino MKR Vidor 4000, PCIeDuino or this Arduino Zero card by bobricius
• Breakouts for modems and routers, such as this Onion Omega mPCI-E breakout
• Working with "true" mPCI-E cards that actually use the PCI-E lanes
• Bluetooth
• If you have a WiFi+BT mPCI-E card, Bluetooth will be USB-connected and you can use it as a standalone Bluetooth adapter - with a good antenna, too!
• 4G, 3G and other modems that use the MiniPCI-E socket
• mSATA, EEE "FLASH-CONN" and other mPCI-E form-factor SSDs
• Other mPCI-E cards (GPS, WiMax etc.)

You need a 3.3V supply for mPCI-E cards - you should be able to feed your card off a Raspberry Pi GPIO header 3.3V, or something like LM1117-33. If you want to power your card off the USB connector out of the box, pick the "3.3V regulator" option when buying and I'll add a 1A LDO to your board. Certain 3G/4G/etc. modems might need 3.5V-4.2V, check the datasheet - however, cards used in laptops will work fine with 3.3V. In case of "true" mPCI-E cards where you will actually be connecting to the PCI-E (CLK+-, PET+/- and PER+-) interface (and not just a microcontroller mPCIe board reusing these pins for something), you might need to connect a 1.5V supply to AVCC - again, you can select the "1.5V regulator" option for me to add that. I can also throw in a pair of WiFi antennas I harvested from a dead laptop - I have a small stock of those. Those antennas will have a u.FL connector - the one that's the most commonly used on miniPCI-E WiFi cards.

Notes:

• All "1.5V" pins are connected together into a 1.5V power bus through a 0R resistor, but are broken out to pin headers anyway - if you have a PCI-E card that uses the 1.5V pins for something else and you pick the "1.5V regulator" option, just desolder or snip off the 0R resistors on pins which you need to access directly (very easy) and you're good to go.
• The "low-profile socket" version is currently cheaper because I have hardly any full-height mPCIe socket boards available, and I need to do some soldering work to swap sockets between boards to send you a full-height board. I will get more stock of full-height boards in about a month or so and then I'll be able to sell them cheaper! Low-profile boards work well even with dual-sided 3G/4G modem cards, the SIM slot gets in the way a bit but not too much, it'll be at an angle but that's about it.