M.2 KEYE Pinout Reference
The IoTSploit hardware uses M.2 KEYE connectors for modular expansion. This guide explains the pinout configurations for both the Main Board and Function Board interfaces.
Warning
The Main Board and Function Board have different pinouts and CANNOT be mixed or interchanged. Connecting boards incorrectly may cause permanent hardware damage.
Main Board Pinout
Overview
The Main Board M.2 KEYE connector features 75 pins arranged in two rows:
Left side: Odd-numbered pins (1-75)
Right side: Even-numbered pins (2-74)
Pin Categories
The pins are organized into several functional groups:
USB Interface
USB Data (D+/D-): Pins 3-6
USB Power (USB_VIN): Pin 9
USB Host Interface: Pins 35-38
Power and Ground
3.3V Power: Pins 2, 73
Ground (GND): Pins 1, 7, 33, 39, 45, 75
Battery Input (BATT_VIN): Pin 49
Communication Interfaces
I2C: SDA (11), SCL (13), ~{INT} (16)
UART: Multiple interfaces on pins 13-22
SPI: Multiple interfaces including SDO/SDI
CAN Bus: RX (41), TX (43)
Ethernet: TX+/- and RX+/- pairs
Complete Main Board Pinout Table
Pin |
Connection |
Function 1 |
Function 2 |
Connection |
Pin |
|---|---|---|---|---|---|
1 |
GND |
3.3V |
2 |
||
3 |
USB_D+ |
3.3V_EN |
4 |
||
5 |
USB_D- |
RESET |
6 |
||
7 |
GND |
G11 |
O |
8 |
|
9 |
USB_VIN |
D0 |
10 |
||
11 |
~{BOOT} |
I2C_SDA |
12 |
||
13 |
RTS1 |
I2C_SCL |
14 |
||
15 |
CTS1 |
I2C_~{INT} |
16 |
||
17 |
TDI |
D1/CAM_TRIG |
18 |
||
19 |
TDO |
RX2 |
20 |
||
21 |
TCK/SWDCK |
TX2 |
22 |
||
23 |
TMS/SWDIO |
/ |
24 |
||
25 |
/ |
/ |
26 |
||
27 |
/ |
/ |
28 |
||
29 |
/ |
/ |
30 |
||
31 |
/ |
TRST |
32 |
||
33 |
GND |
A0 |
34 |
||
35 |
USBHOST_D+ |
GND |
36 |
||
37 |
USBHOST_D- |
A1 |
38 |
||
39 |
GND |
G0/BUS0 |
F1_53 |
40 |
|
41 |
O |
CAN-RX(CANL) |
G1/BUS1 |
F1_55 |
42 |
43 |
O |
CAN-TX(CANH) |
G2/BUS2 |
F1_57 |
44 |
45 |
GND |
G3/BUS3 |
F1_59 |
46 |
|
47 |
O |
RX3 |
G4/BUS4 |
F1_61 |
48 |
49 |
BATT_VIN/3 |
TX3 |
O |
50 |
|
51 |
TX1 |
ETH_TX+ |
52 |
||
53 |
RX1 |
ETH_TX- |
54 |
||
55 |
SPI_~{CS} |
ETH_RX+ |
56 |
||
57 |
SPI_SCK |
ETH_RX- |
58 |
||
59 |
SPI_SDO |
SPI_SCK1/SDIO_CLK |
60 |
||
61 |
SPI_SDI |
SPI_SDO1/SDIO_CMD |
62 |
||
63 |
O |
G10/ADC_D+/CAM_VSYNC |
SPI_SDI1/SDIO_DATA0 |
64 |
|
65 |
O |
G9/ADC_D-/CAM_HSYNC |
SDIO_DATA1 |
66 |
|
67 |
O |
G8 |
SDIO_DATA2 |
68 |
|
69 |
F2_57 |
G7/BUS7 |
SPI_~{CS1}/SDIO_DATA3 |
70 |
|
71 |
F2_55 |
G6/BUS6 |
RTC_3V |
72 |
|
73 |
F2_53 |
G5/BUS5 |
3.3V |
74 |
|
75 |
GND |
Function Board Pinout
Overview
The Function Board uses the same M.2 KEYE form factor but with a different pin assignment optimized for debugging and expansion capabilities.
Interface Groups
SPI Interfaces
Primary SPI: SCK (3), SDI (5), SDO (7)
Secondary SPI: SCK1 (42), SDI1 (48), SDO1 (46), ~{CS1} (50)
UART Interfaces
UART1: TX1 (12), RX1 (14)
UART2: TX2 (22), RX2 (20)
Function UART: FUNC_TX (13), FUNC_RX (15), FUNC_RTS (16), FUNC_CTS (18)
Debug Interfaces
JTAG/SWD: TDI (56), TDO (58), TCK/SWDCK (60), TMS/SWDIO (62), TRST (64)
DFU: DFU_FC_TX (4), DFU_FC_RX (6), DFU_~{ACTIVE} (10), DFU_~{BOOT} (66), DFU_~{RST} (68)
Communication Interfaces
I2C: SDA (19), SCL (21), ~{INT} (23)
CAN: TX/CANH (41), RX/CANL (43)
Ethernet: TX+/- (63, 65), RX+/- (67, 69)
USB Slave: D+ (35), D- (37)
Power and Control
Power: 3.3V (73), VCC (72, 74), GND (multiple pins)
Control: PWR_EN (71)
Complete Function Board Pinout Table
Pin |
Function 1 |
Function 2 |
Pin |
|---|---|---|---|
1 |
GND |
GND |
2 |
3 |
SPI_SCK |
DFU_FC_TX |
4 |
5 |
SPI_SDI |
DFU_FC_RX |
6 |
7 |
SPI_SDO |
GND |
8 |
9 |
DFU_~{ACTIVE} |
10 |
|
11 |
TX1 |
12 |
|
13 |
FUNC_TX |
RX1 |
14 |
15 |
FUNC_RX |
FUNC_RTS |
16 |
17 |
FUNC_CTS |
18 |
|
19 |
I2C_SDA |
RX2 |
20 |
21 |
I2C_SCL |
TX2 |
22 |
23 |
I2C_~{INT} |
/ |
24 |
25 |
/ |
/ |
26 |
27 |
/ |
/ |
28 |
29 |
/ |
/ |
30 |
31 |
/ |
EEPROM_A2 |
32 |
33 |
GND |
EEPROM_A1 |
34 |
35 |
USBSLAVE_D+ |
EEPROM_A0 |
36 |
37 |
USBSLAVE_D- |
A0 |
38 |
39 |
GND |
EEPROM_WP |
40 |
41 |
CAN-TX(CANH) |
SPI_SCK1 |
42 |
43 |
CAN-RX(CANL) |
GND |
44 |
45 |
GND |
SPI_SDO1 |
46 |
47 |
F0/~{INT} |
SPI_SDI1 |
48 |
49 |
F1/~{CS} |
SPI_~{CS1} |
50 |
51 |
F2/PWM |
USB_D+ |
52 |
53 |
F3 |
USB_D- |
54 |
55 |
F4 |
TDI |
56 |
57 |
F5 |
TDO |
58 |
59 |
F6 |
TCK/SWDCK |
60 |
61 |
F7 |
TMS/SWDIO |
62 |
63 |
ETH_TX+ |
TRST |
64 |
65 |
ETH_TX- |
DFU_~{BOOT} |
66 |
67 |
ETH_RX+ |
DFU_~{RST} |
68 |
69 |
ETH_RX- |
USB_VIN |
70 |
71 |
PWR_EN |
VCC |
72 |
73 |
3.3V |
VCC |
74 |
75 |
Usage Notes
Always verify board type before connection
Check voltage levels before connecting external devices
Pay attention to ground connections when designing custom hardware
The Function Board provides additional debugging capabilities
Multiple interface options allow for flexible connectivity
Note
The Function Board provides additional debugging capabilities through the DFU interface and expanded GPIO options (F0-F7).
Warning
Always verify the board type before connection. The Function Board and Main Board have different pinouts and are not compatible with each other.