3.4 EXP Header
The EXP header is an angled 20-pin expansion header that allows connection of peripherals or plugin boards to the kit. It is located on
the right-hand side of the mainboard, and it contains several I/O pins that can be used with most of the EFR32 Wireless Gecko's fea-
tures. Additionally, the VMCU, 3V3, and 5V power rails are also exported.
The connector follows a standard which ensures that commonly used peripherals, such as a SPI, a UART, and an I2C bus, are availa-
ble on fixed locations in the connector. The rest of the pins are used for general purpose IO. This allows the definition of expansion
boards (EXP boards) that can plug into several different Silicon Labs Starter Kits.
The figure below shows the pin assignment of the EXP header. Because of limitations in the number of available GPIO pins, some of
the EXP header pins are shared with kit features.
1
2
4
8
6
10
3
5
9
7
12
13
14
11
15
16
17
18
20
19
VMCU
NC
NC
NC
NC
UART_TX / PA0
UART_RX / PA1
I2C_SDA / PC11
5V
3V3
GND
NC
NC
NC
NC
NC
PF3 / GPIO
PC10 / I2C_SCL
BOARD_ID_SDA
BOARD_ID_SCL
Reserved (Board Identification)
EFR32 I/O Pin
Figure 3.3. EXP Header
UG476: Z-Wave 700 - EFR32ZG14 Long Range Wireless Starter Kit User's Guide
Connectors
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