User Guide

3.4 EXP Header
The EXP header is an angled 20-pin expansion header provided to allow connection of peripherals or plugin boards to the kit. It is loca-
ted on the right-hand side of the mainboard, and it contains a number of I/O pins that can be used with most of the BGM220P Wireless
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 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 a number of 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.
12
4
8
6
10
3
5
9
7
12
13
14
11
1516
17
18
20 19
VMCU
SPI_MOSI / PC00
SPI_MISO / PC01
SPI_CLK / PC02
SPI_CS / PC03
UART_TX / PA05
UART_RX / PA06
I2C_SDA / PB03
5V
3V3
GND
NC
NC
PB00 / GPIO
PB01 / GPIO
NC
NC
PB02 / I2C_SCL
BOARD_ID_SDA
BOARD_ID_SCL
Reserved (Board Identification)
BGM220P I/O Pin
Figure 3.3. EXP Header
UG432: BGM220P Wireless Gecko Module Starter Kit User's Guide
Connectors
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