M.2 and Mini PCIe

Edge 2 has two module sockets on the bottom side of the board, each with its own micro-SIM slot:

• An M.2 Key B socket, for 4G and 5G modems, NVMe SSDs and other PCIe or USB modules
• A Mini PCIe socket, for USB modules such as 4G modems, LoRa concentrators and the Mixtile Zigbee and Z-Wave module

Figure 1. The M.2 and Mini PCIe sockets and their SIM slots, on the bottom side

Specifications

	M.2	Mini PCIe
Socket	75-pin, Key B	52-pin
Module sizes	2242, 3042 and 3052	Full size
Interfaces	PCIe 3.0 x2, USB 2.0	USB 2.0
SIM slot	Micro-SIM, marked SIM: M.2	Micro-SIM, marked SIM: mini-PCIe
Module supply	3.8 V, up to 3 A shared by both sockets	3.8 V, up to 3 A shared by both sockets

The Mini PCIe socket carries no PCIe signals, so it only accepts modules that use USB.

The second PCIe lane of the M.2 socket can also be routed to USB 3.0, for modems that need it. A switch on the board, controlled by a GPIO of the SoC, selects between the two. For the setting used by Mixtile OS, see Hardware Interfaces in Mixtile OS.

Pin Assignments

The tables list only the pins that are connected. All other pins are not connected.

M.2

Pin#	PinName	PinType	Input/Output	Signal Description
2, 4, 70, 72, 74	3.8V	Power	Output	Module supply, 3 A maximum in total
3, 5, 11, 27, 33, 39, 45, 51, 57, 71, 73	GND	Power	NA	Power and signal reference ground
6	M2_ONOFF_GPIO1_D2	signal	Output	Module on or off
7	HUB_HOST3_DP	USB	BI	USB 2.0 data, positive
9	HUB_HOST3_DM	USB	BI	USB 2.0 data, negative
10	M2_LED1	signal	Input	Network status LED, active low
23	M2_WAKE_GPIO0_B7	signal	Input	Module wakes the CPU
29	PCIE30_TX1_N / HUB_USB3_SSTXN	PCIe	Output	PCIe 3.0 lane 1 or USB 3.0, transmit, negative
30	M2_UIM_RESET	signal	Input	SIM reset
31	PCIE30_TX1_P / HUB_USB3_SSTXP	PCIe	Output	PCIe 3.0 lane 1 or USB 3.0, transmit, positive
32	M2_UIM_CLK	signal	Input	SIM clock
34	M2_UIM_DATA	signal	Input	SIM data
35	PCIE30_RX1N / HUB_USB3_SSRXN	PCIe	Input	PCIe 3.0 lane 1 or USB 3.0, receive, negative
36	M2_UIM_PWR	signal	Input	SIM power
37	PCIE30_RX1P / HUB_USB3_SSRXP	PCIe	Input	PCIe 3.0 lane 1 or USB 3.0, receive, positive
41	PCIE30_TX0_N	PCIe	Output	PCIe 3.0 lane 0, transmit, negative
43	PCIE30_TX0_P	PCIe	Output	PCIe 3.0 lane 0, transmit, positive
47	PCIE30_RX0N	PCIe	Input	PCIe 3.0 lane 0, receive, negative
49	PCIE30_RX0P	PCIe	Input	PCIe 3.0 lane 0, receive, positive
50	PCIE30X2_PERSTN_M1	signal	Output	PCIe reset
52	PCIE30X2_CLKREQN_M1	signal	Input	PCIe clock request
53	CLK0N_CON	PCIe	Output	PCIe 100 MHz reference clock, negative
54	PCIE30X2_WAKEN_M1	signal	Input	PCIe wake
55	CLK0P_CON	PCIe	Output	PCIe 100 MHz reference clock, positive
66	M2_SIM_DETECT	signal	Output	SIM card detect
67	M2_RESET_GPIO3_B5	signal	Output	Module reset
68	CLK32K_OUT0	signal	Output	32.768 kHz clock

Mini PCIe

Pin#	PinName	PinType	Input/Output	Signal Description
1	WAKEUP_MINIPCIE_GPIO0_C1	signal	Input	Module wakes the CPU
2, 24, 39, 41, 52	3.8V	Power	Output	Module supply, 3 A maximum in total
4, 9, 15, 18, 21, 26, 27, 29, 34, 35, 40, 50	GND	Power	NA	Power and signal reference ground
8	UIM_PWR	Power	Input	SIM power
10	UIM_DATA	signal	Input	SIM data
12	UIM_CLK	signal	Input	SIM clock
14	UIM_RESET	signal	Input	SIM reset
22	MiniPCIE_reset_GPIO3_D4	signal	Output	Module reset
36	USB2_HOST2_DM	USB	BI	USB 2.0 data, negative
38	USB2_HOST2_DP	USB	BI	USB 2.0 data, positive
42	LED	signal	Input	Status LED
44	SIM_DETECT	signal	Output	SIM card detect

Install a Module

1. Shut down Edge 2 and disconnect the power supply.
2. Turn the board over. The sockets are on the bottom side. If the board is in the Edge 2 Kit enclosure, remove the bottom cover, see Edge 2 Kit Enclosure.
3. If the module uses a SIM card, insert the micro-SIM into the slot for that socket.
4. Line up the notch in the module's edge with the key in the socket, and insert the module at an angle.
5. Press the module down flat, and secure it with the screw.
6. If the module has antenna connectors, connect the antennas before you use the module.
7. Reconnect the power supply.

Figure 2. A module installed in the Mini PCIe socket

Verify the Module

Log in to the board, see Connect to Edge 2, and check that the module is listed:

• A module that uses PCIe, such as an NVMe SSD, appears in the output of lspci:

  Edge 2

  lspci

  An NVMe SSD also appears as /dev/nvme0n1 in the output of lsblk.

• A module that uses USB, such as most modems and the Mini PCIe modules, appears in the output of lsusb:

  Edge 2

  lsusb

To work, the module also needs a Linux driver and, for many modules, firmware and user-space software in the running system.

Modules Tested with Earlier Systems

Mixtile tested the following modules on Edge 2 with its earlier Android and Debian 11 images. They have not been tested with Mixtile OS.

Socket	Module
M.2	Quectel EM06-A (4G), Quectel RM500Q-AE (5G), Western Digital PC SN520 NVMe SSD
Mini PCIe	Quectel EC25 (4G), RAK5146 LoRa concentrator