EFR32xG21B 2.4 GHz 20 dBm (xG21-RB4196B)
Overview
The EFR32xG21B +20 dBm Radio Board is the radio board delivered with the EFR32xG21 Pro Kit +20 dBm, and is also available standalone. It contains a Wireless System-On-Chip from the EFR32MG21B family built on an ARM Cortex®-M33 processor with excellent low power capabilities.
The radio board plugs into the Wireless Pro Kit Mainboard BRD4002A and is supported in Zephyr as one of several Radio Boards.
Hardware
EFR32MG21B020F1024IM32 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
Inverted-F PCB antenna
Crystals for LFXO (32.768 kHz) and HFXO (38.4 MHz).
For more information about the EFR32MG21 SoC and BRD4196B board, refer to these documents:
Supported Features
The xg21_rb4196b board supports the hardware features listed below.
- on-chip / on-board
- Feature integrated in the SoC / present on the board.
- 2 / 2
-
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files. -
vnd,foo -
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.
xg21_rb4196b/efr32mg21b020f1024im32 target
On-target memory for this board target: 96 KiB of RAM, 1 MiB of Flash.
Type |
Location |
Description |
Compatible |
|---|---|---|---|
CPU |
on-chip |
ARM Cortex-M33 CPU1 |
|
ADC |
on-chip |
Silicon Labs Series 2 IADC1 |
|
Bluetooth |
on-chip |
Silicon Labs Series 2 Bluetooth HCI1 |
|
Clock control |
on-chip |
Silicon Labs Series 2 CMU1 |
|
on-chip |
Silicon Labs Series 2 HFXO1 |
||
on-chip |
Silicon Labs Series 2 HFRCODPLL1 |
||
on-chip |
Generic fixed-rate clock provider3 |
||
on-chip |
Silicon Labs Series 2 LFXO1 |
||
on-chip |
Silicon Labs Series 2 LFRCO1 |
||
on-chip |
Silicon Labs Series 2 HFRCOEM231 |
||
on-chip |
Generic fixed factor clock provider15 |
||
Comparator |
on-chip |
Silicon Labs Series 2 ACMP2 |
|
Counter |
on-chip |
||
on-chip |
Silicon Labs Series 2 BURTC1 |
||
on-chip |
Silicon Labs PROTIMER counter1 |
||
CRC |
on-chip |
Silabs General Purpose CRC1 |
|
Cryptographic accelerator |
on-chip |
Silicon Labs Series 2 SE Mailbox1 |
|
Debug |
on-chip |
Silicon Labs Packet Trace Interface1 |
|
on-chip |
ARMv8 instrumentation trace macrocell1 |
||
Display |
on-board |
Sharp LS0XX memory display controller1 |
|
DMA |
on-chip |
Silicon Labs Series 2 LDMA1 |
|
Flash controller |
on-chip |
Silicon Labs Series 2 MSC1 |
|
GPIO & Headers |
on-chip |
Silicon Labs Series 2 GPIO Peripheral1 |
|
on-chip |
Silicon Labs Series 2 GPIO Port4 |
||
on-board |
Silicon Labs Kit Expansion Header1 |
||
I2C |
on-chip |
Silicon Labs Series 2 I2C2 |
|
IEEE 802.15.4 |
on-chip |
Silicon Labs EFR32 IEEE 802.15.4 radio1 |
|
Input |
on-board |
Group of GPIO-bound input keys1 |
|
Interrupt controller |
on-chip |
ARMv8-M NVIC (Nested Vectored Interrupt Controller)1 |
|
LED |
on-board |
Group of GPIO-controlled LEDs1 |
|
on-board |
Group of PWM-controlled LEDs1 |
||
MMU / MPU |
on-chip |
ARMv8-M MPU (Memory Protection Unit)1 |
|
MTD |
on-chip |
Flash node1 |
|
Networking |
on-chip |
Silicon Labs Series 2 Radio Interface1 |
|
Pin control |
on-chip |
Silicon Labs Series 2 DBUS Pin Controller1 |
|
PWM |
on-chip |
||
on-chip |
Silicon Labs LETIMER PWM1 |
||
Retained memory |
on-chip |
Silicon Labs Series 2 BURAM1 |
|
RTC |
on-chip |
Silicon Labs Series 2 RTCC1 |
|
Serial controller |
on-chip |
||
SPI |
on-chip |
Silicon Labs Series 2 USART1 |
|
SRAM |
on-chip |
Generic on-chip SRAM1 |
|
Timer |
on-chip |
ARMv8-M System Tick1 |
|
on-chip |
|||
on-chip |
Silicon Labs LETIMER1 |
||
Watchdog |
on-chip |
Connections and IOs
The following table describes the connections provided by the BRD4002A mainboard when the BRD4196B radio board is mounted.
Name |
Function |
Usage |
|---|---|---|
PA0 |
GPIO |
Display EXTCOMIN |
PA3 |
SWO |
Serial wire trace |
PA5 |
USART0_TX |
Virtual COM port transmit |
PA6 |
USART0_RX |
Virtual COM port receive |
PB0 |
GPIO |
Push button 0 |
PB1 |
GPIO |
Push button 1 |
PC0 |
USART2_TX |
Display serial data |
PC2 |
USART2_CLK |
Display serial clock |
PC3 |
GPIO |
Display chip select |
PC4 |
PTI_DOUT |
Packet Trace Interface data |
PC5 |
PTI_DFRAME |
Packet Trace Interface frame |
PD2 |
TIMER0_CC0 |
LED0 and PWM LED0 |
PD3 |
TIMER0_CC1 |
LED1 and PWM LED1 |
PD4 |
GPIO |
Board controller enable |
System Clock
The EFR32MG21B SoC is configured to use the HFRCODPLL oscillator at 80 MHz as the system clock, locked to the 38.4 MHz external crystal oscillator on the board.
Serial Port
The EFR32MG21B SoC has three USARTs. USART0 is connected to the board controller and is used for the console.
Programming and Debugging
The xg21_rb4196b board supports the runners and associated west commands listed below.
| flash | debug | rtt | debugserver | attach | reset | |
|---|---|---|---|---|---|---|
| jlink | ✅ (default) | ✅ (default) | ✅ | ✅ | ✅ | ✅ |
| openocd | ✅ | ✅ | ✅ | ✅ | ✅ | |
| silabs_commander | ✅ |
Flashing
Connect the BRD4002A board with a mounted BRD4196B radio board 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 xg21_rb4196b 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! xg21_rb4196b
Bluetooth
To use Bluetooth functionality, run the command below to retrieve necessary binary blobs from the Silicon Labs HAL repository.
west blobs fetch hal_silabs
Then build the Zephyr kernel and a Bluetooth sample with the following command. The Observer sample application is used in this example.
# From the root of the zephyr repository
west build -b xg21_rb4196b samples/bluetooth/observer