EFR32xG21 2.4 GHz 20 dBm (SLWRB4180A)
Overview
The EFR32MG21 Mighty Gecko Radio Board is one of the two radio boards delivered with EFR32-SLWSTK6006A Website. It contains a Wireless System-On-Chip from the EFR32MG21 family built on an ARM Cortex®-M33F processor with excellent low power capabilities.
The BRD4180A a.k.a. SLWRB4180A radio board plugs into the Wireless Starter Kit Mainboard BRD4001A and is supported as one of Radio Boards.
Hardware
EFR32MG21A020F1024IM32 Mighty Gecko SoC
CPU core: ARM Cortex®-M33 with FPU
Flash memory: 1024 kB
RAM: 96 kB
Transmit power: up to +20 dBm
Operation frequency: 2.4 GHz
Crystals for LFXO (32.768 kHz) and HFXO (38.4 MHz).
For more information about the EFR32MG21 SoC and BRD4180A board, refer to these documents:
Supported Features
The board configuration supports the following hardware features:
Interface |
Controller |
Driver/Component |
|---|---|---|
MPU |
on-chip |
memory protection unit |
NVIC |
on-chip |
nested vector interrupt controller |
SYSTICK |
on-chip |
systick |
COUNTER |
on-chip |
rtcc |
FLASH |
on-chip |
flash memory |
GPIO |
on-chip |
gpio |
UART |
on-chip |
serial port-polling; serial port-interrupt |
I2C |
on-chip |
i2c port-polling |
WATCHDOG |
on-chip |
watchdog |
Other hardware features are currently not supported by the port.
Connections and IOs
In the following table, the column Name contains Pin names. For example, PA2 means Pin number 2 on PORTA, as used in the board’s datasheets and manuals.
Name |
Function |
Usage |
|---|---|---|
PB0 |
GPIO |
LED0 |
PB1 |
GPIO |
LED1 |
PD2 |
GPIO |
Push Button PB0 |
PD3 |
GPIO |
Push Button PB1 |
PD4 |
GPIO |
Board Controller Enable EFM_BC_EN |
PA5 |
USART1_TX |
UART Console EFM_BC_TX US1_TX |
PA6 |
USART1_RX |
UART Console EFM_BC_RX US1_RX |
The default configuration can be found in boards/silabs/radio_boards/slwrb4180a/slwrb4180a_defconfig
System Clock
The EFR32MG21 SoC is configured to use the 38.4 MHz external oscillator on the board.
Serial Port
The EFR32MG21 SoC has three USARTs. USART0 is connected to the board controller and is used for the console.
Programming and Debugging
Flashing
Connect the BRD4001A board with a mounted BRD4180A radio module to your host computer using the USB port.
Here is an example for the Hello World application.
# From the root of the zephyr repository
west build -b slwrb4180a samples/hello_world
west flash
Open a serial terminal (minicom, putty, etc.) with the following settings:
Speed: 115200
Data: 8 bits
Parity: None
Stop bits: 1
Reset the board and you should see the following message in the terminal:
Hello World! slwrb4180a