6.2 Expansion Header
On the right hand side of the board an angled 20-pin expansion header is provided to allow connection of peripherals or plugin boards.
The connecter contains a number of I/O pins that can be used with most of the Busy Bee's features. Additionally, the VMCU, 3V3 and
5V power rails are also exported.
The figure below shows the pin assignment of the expansion header. With the exception of a few pins, most of the expansion header's
pins are the same as those on the EFM32 Gecko or EFM32 Tiny Gecko starter kits.
Figure 6.2. Expansion Header
Some of the chip peripheral functions that are available on the expansion header are listed in the table below.
Table 6.1. Some Peripheral Functions Available on Expansion Header
Peripheral
Peripheral pin
MCU Pin
EXP Header pin
number
UART1
UART1 TX
P2.1
12
UART1 RX
P2.2
14
SPI0
SPI0 SCK
P0.6
8
SPI0 MISO
P0.7
6
SPI0 MOSI
P1.0
4
SPI0 CS
P1.1
10
SMBus
SMBus0 SDA
P1.2
16
SMBus0 SCL
P1.3
15
PCA0
PCA0 CEX0
P1.4
5
PCA0 CEX1
P1.5
7
PCA0 CEX2
P1.6
9
I2CSLAVE0
I2CSLAVE0 SDA
P1.5
7
I2CSLAVE0 SCL
P1.6
9
VREF
VREF
P0.0
3
ADC0
Input
Any supported pin (see Reference Manual for more information)
Multiple
CNVSTR
P0.6
8
UG237: EFM8BB2-SLSTK2021A User's Guide
Connectors
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