Expansion Header - Silicon Laboratories UG179 User Manual

3.4 Expansion Header

On the right hand side of the Wireless STK Mainboard an angled 20-pin expansion header is provided to allow connection of peripher-
als or plugin boards. The connector contains a number of I/O pins that can be used with most of the EFR32 Mighty Gecko's features.
Additionally, the VMCU, 3V3 and 5V power rails are also exported.
The connector follows a standard which ensures that commonly used peripherals such as an SPI, a UART and an I2C bus are available
on fixed locations in the connector. The rest of the pins are used for general purpose IO. This allows the definition of expansion boards
that can plug into a number of different Silicon Labs Starter Kits.
The figure below shows the pin assignment of the expansion header. Because of limitations in the number of available GPIO pins,
some of the expansion header pins are shared with kit features.
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3V3 20
5V 18
I2C_SDA / PC11 16
UART_RX / PA1 14
UART_TX / PA0
12
SPI_CS / PC9 10
8
SPI_CLK / PC8
SPI_MISO / PC7 6
SPI_MOSI / PC6 4
VMCU 2
EFR32 I/O Pin
Reserved (Board Identification)
Figure 3.3. Expansion Header
UG179: EFR32MG1 2400/915 MHz 19.5 dBm Radio Board User's Guide
19 Board ID SDA
17 Board ID SCL
15 PC10 / I2C_SCL
13 PF3 / GPIO
11 PF4 / GPIO
9 PF7 / GPIO
7
PF6 / GPIO
5 PA3 / GPIO
3 PA2 / GPIO
1 GND
Connectors
Rev. 1.01 | 9