4.1 EXP Header
On the left-hand side of the WFM200S Wi-Fi Expansion Kit, a right-angle female 20-pin EXP header is provided to connect to one of
Silicon Labs’ supported Starter Kits. The EXP header on the Starter Kits follows a standard which ensures that commonly used periph-
erals such as an SPI, a UART, and an I
2
C bus, are available on fixed locations on the connector. Additionally, the VMCU, 3V3 and 5 V
power rails are also available on the expansion header. For detailed information regarding the pinout to the expansion header on a
specific Starter Kit, consult the accompanying user’s guide.
The figure below shows how the WFM200S Wi-Fi Transceiver Module is connected to the connector and the peripheral functions that
are available.
1
2
4
8
6
10
3
5
9
7
12
13
14
11
15
16
17
18
20
19
VMCU
SPI_MOSI / SDIO_DAT1
SPI_MISO / SDIO_DAT0
SPI_SCLK / SDIO_CMD
SPI_CS / SDIO_CLK
SPI_WIRQ / SDIO_DAT3
SDIO_DAT2
Not Connected (NC)
5V
3V3
GND
GPIO_WUP
Not Connected (NC)
RESETn
HIF_SEL_CTRL
Not Connected (NC)
Not Connected (NC)
Not Connected (NC)
BOARD_ID_SDA
BOARD_ID_SCL
Reserved (Board Identification)
WFM200S I/O Pin
Figure 4.2. Expansion Header
4.1.1 Pass-through EXP Header
The WFM200S Wi-Fi Expansion Kit features a footprint for a secondary EXP header. All signals from the EXP header, including those
that are not connected to any features on the WFM200S Wi-Fi Expansion Kit, are directly tied to the corresponding pins in the footprint,
allowing daisy-chaining of additional expansion boards if a connector is soldered in.
UG407: WFM200S Wi-Fi
®
Expansion Kit User's Guide
Connectors
silabs.com
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