Silicon Laboratories SLWRB4150A User manual

UG178: EFR32MG 2400/868 MHz 13 dBm
Dual Band Radio Board
The SLWRB4150A Radio Board for the Wireless Starter Kit Main-
board is an excellent starting point to get familiar with the
EFR32™ Mighty Gecko Wireless System-on-Chip.
The Wireless Starter Kit Mainboard contains sensors and peripherals demonstrating
some of the Mighty Gecko's many capabilities. These together provide all necessary
tools for developing a Silicon Labs wireless application.
The WSTK Mainboard is included with all Silicon Labs Wireless Starter Kits. It is not in-
cluded when purchasing a single radio board.
RADIO BOARD FEATURES
• EFR32 Mighty Gecko Wireless SoC with
256 kB Flash and 32 kB RAM.
(EFR32MG1P233F256GM48)
• Inverted-F PCB antenna (2.4 GHz band)
• SMA connector (868 MHz band)
WSTK MAINBOARD FEATURES
• Ethernet and USB connectivity
•Advanced Energy Monitor
• Packet Trace Interface support
• SEGGER J-Link on-board debugger
• Debug Multiplexer supporting external
hardware as well as radio board
• Silicon Labs' Si7021 Relative Humidity and
Temperature sensor
• Ultra low power 128x128 pixel Memory
LCD
• User LEDs / Pushbuttons
• 20-pin 2.54 mm header for expansion
boards
• Breakout pads for direct access to all radio
I/O pins
• Power sources includes USB, CR2032
coin cell and AA batteries.
SOFTWARE SUPPORT
• Simplicity Studio™
•Energy Profiler
• Network Analyzer
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1. Introduction
The SLWRB4150A Radio Board is a single EFR32MG 2400/868 MHz 13 dBm radio board for the Wireless Starter Kit Mainboard.
A radio board and a mainboard used together makes a complete development platform for Silicon Labs EFR32 Mighty Gecko Wireless
System-on-Chips.
The Wireless Starter Kit Mainboard features an on-board J-Link debugger, an Advanced Energy Monitor for real-time current and volt-
age monitoring, a virtual COM port interface, and access to the Packet Trace Interface (PTI).
All debug functionality, including AEM, VCOM and PTI, can also be used towards an external target instead of the connected radio
board.
To further enhance the WSTK usability, the WSTK Mainboard contains sensors and peripherals demonstrating some of the Wireless
SoC's many capabilities.
The radio board features an EFR32 and the RF interface. Please refer to the Radio Board Reference Manual for detailed specifications
and RF performance figures.
1.1 Kit Contents
The following items are included with the SLWRB4150A:
• 1x BRD4150A EFR32MG 2400/868 MHz 13 dBm Radio Board
• 1x 868 MHz antenna with SMA connector
1.2 Getting Started
Detailed instructions for how to get started can be found on the Silicon Labs web pages:
http://www.silabs.com/start-efr32mg
UG178: EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board
Introduction
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2. Kit Hardware Overview
A view of the EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board with a Wireless STK Mainboard is shown below.
On-board USB and
Ethernet J-Link
Debugger
Radio Board Breakout Pads
Plug-in Radio Board
Si7021 Humidity and
Temperature Sensor
EXP-header for
expansion boards
Serial-port, packet trace and Advanced
Energy Monitoring header
ARM Coresight 19-pin
trace/debug header
Ultra-low power 128x128
pixel memory LCD,
buttons and LEDs
Battery or
USB power
USB-serial-port
Packet-trace
Advanced Energy
Monitoring
Figure 2.1. SLWRB4150A with Wireless STK Mainboard
UG178: EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board
Kit Hardware Overview
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3. Block Diagram
A system overview of the EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board used together with an Wireless STK Mainboard is
shown in the figure below.
Debug
USB Mini-B
Connector
UART
RJ-45 Ethernet
Connector
Packet Trace
AEM
Multiplexer
Debug
UART
ETM Trace
Packet Trace
AEM
Debug
UART
Packet Trace
AEM
Simplicity
Connector
Debug
Connector
Board
Controller
OUT
IN
MCU
SMA
Connector
868 MHz RF
2.4 GHz RF
Inverted-F
PCB Antenna
EFR32MG
Wireless SoC
ETM Trace
128 x 128 pixel
Memory LCD
I2C Si7021
Temperature
& Humidity
Sensor
SPI 8 Mbit
MX25R
Serial Flash
GPIO
EXP
Header
User Buttons
& LEDs
GPIO
Figure 3.1. Kit Block Diagram
UG178: EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board
Block Diagram
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4. Connectors
This chapter gives you an overview of the Wireless Starter Kit Mainboard connectivity. The placement of the connectors can be seen in
the figure below.
Simplicity
Connector
In/Out Debug
Header
GND
GND
5V
5V
P25
P24
P27
P26
P29
P28
P31
P30
P33
P32
P35
P34
P37
P36
P39
P38
P41
P40
P43
P42
P45
P44
GND
GND
NC
NC
Radio Board
Connectors
Expansion
Header
GND
GND
VMCU
VMCU
P1
P0
P3
P2
P5
P4
P7
P6
P9
P8
P11
P10
P13
P12
P15
P14
P17
P16
P19
P18
P21
P20
GND
GND
P23
P22
VRF
VRF
3V3
3V3
Figure 4.1. Mainboard Connector Layout
4.1 Breakout Pads
Most of the EFR32's pins are routed from the radio board to breakout pads at the top and bottom edges of the Wireless Starter Kit
Mainboard. A 2.54 mm pitch pin header can be soldered on for easy access to the pins. The figure below shows you how the pins of
the EFR32 maps to the pin numbers printed on the breakout pads. To see the available functions on each, please refer to the
EFR32MG1P233F256GM48 Data Sheet.
GND
VMCU
P23 / NC
P21 / NC
P19 / NC
P17 / NC
GND
P15 / NC
P13 / PC11 / I2C_SDA
P11 / PA1 / VCOM_RX
P9 / PA0 / VCOM_TX
P7 / PC9
P5 / PC8 / FLASH_SCLK / DISP_SCLK
P3 / PC7 / FLASH_MISO
P1 / PC6 / FLASH_MOSI / DISP_SI
GNDGND
5V5V
NCNC
P45 / NCNC / P44
P43 / NCNC / P42
P41 / NCNC / P40
3V33V3
P39 / NCNC / P38
P37 / PD15 / SENSOR_ENABLENC / P36
P35 / PD15 / DISP_ENABLENC / P34
P33 / PD14 / DISP_SCSLED1 / PF5 / P32
P31 / PD13 / DISP_EXTCOMINNC / P30
P29 / NCDBG_TDO_SWO / PF2 / P28
P27 / NCDBG_TMS_SWDIO / PF1 / P26
P25 / NCDBG_TCK_SWCLK / PF0 / P24
GNDGND
VRF
GND
VMCU
PTI_FRAME / PB13 / P22
PTI_DATA / PB12 / P20
PTI_CLK / PB11 / P18
VCOM_ENABLE / PA5 / P16
GND
FLASH_SCS / PA4 / P14
I2C_SCL / PC10 / P12
DBG_TDI / PF3 / P10
LED0 / PF4 / P8
BTN1 / PF7 / P6
BTN0 / PF6 / P4
VCOM_RTS / PA3 / P2
VCOM_CTS / PA2 / P0
VRF
J101 J102
Figure 4.2. Radio Board Pin Mapping on Breakout Pads
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Connectors
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4.2 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 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 for the EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board.
Because of limitations in the number of available GPIO pins, some of the expansion 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 / PC6
SPI_MISO / PC7
SPI_CLK / PC8
SPI_CS / PC9
UART_TX / PA0
UART_RX / PA1
I2C_SDA / PC11
5V
3V3
GND
PA2 / GPIO
PA3 / GPIO
PF6 / GPIO
PF7 / GPIO
PF4 / GPIO
PF3 / GPIO
PC10 / I2C_SCL
Board ID SDA
Board ID SCL
Reserved (Board Identification)
EFR32 I/O Pin
Figure 4.3. Expansion Header
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Connectors
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4.2.1 Expansion Header Pin-out
The pin-routing on the EFR32 is very flexible, so most peripherals can be routed to any pin. However, many pins are shared between
the Expansion Header and other functions on the Wireless STK Mainboard. Table 4.1 Expansion Header Pinout on page 6 includes
an overview of the mainboard features that share pins with the Expansion Header.
Table 4.1. Expansion Header Pinout
Pin Connection EXP Header function Shared feature Peripheral mapping
20 3V3 Board controller supply
18 5V Board USB voltage
16 PC11 I2C_SDA SENSOR_I2C_SDA I2C1_SDA #16
14 PA1 UART_RX VCOM_RX_MISO USART0_RX #0
12 PA0 UART_TX VCOM_TX_MOSI USART0_TX #0
10 PC9 SPI_CS USART1_CS #11
8 PC8 SPI_SCLK FLASH_SCLK, DISP_SCLK USART1_CLK #11
6 PC7 SPI_MISO FLASH_MISO USART1_RX #11
4 PC6 SPI_MOSI FLASH_MOSI, DISP_MOSI USART1_TX #11
2 VMCU EFR32 voltage domain, included in AEM measurements.
19 BOARD_ID_SDA Connected to Board Controller for identification of add-on boards.
17 BOARD_ID_SCL Connected to Board Controller for identification of add-on boards.
15 PC10 I2C_SCL SENSOR_I2C_SCL I2C1_SCL #14
13 PF3 GPIO DBG_TDI
11 PF4 GPIO LED0
9 PF7 GPIO BTN1
7 PF6 GPIO BTN0
5 PA3 GPIO VCOM_RTS_CS USART0_CS #0
3 PA2 GPIO VCOM_CTS_SCLK USART0_CLK #0
1 GND Ground
Note: Pin PF3 is used for DBG_TDI in JTAG mode only. When Serial Wire Debugging is used, PF3 can be used for other purposes.
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Connectors
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4.3 Debug Connector
The Debug Connector serves multiple purposes based on the "debug mode" setting which can be configured in Simplicity Studio. When
mode is set to "Debug IN", this connector allows an external debug emulator to be used with the radio board EFR32. When set to "De-
bug OUT", this connector allows the kit to be used as a debugger towards an external target. When set to "Debug MCU" (default), this
connector is isolated from the debug interface of both the Board Controller and the on-board target device.
Because this connector is automatically switched to support the different operating modes, it is only available when the Board Controller
is powered (J-Link USB cable connected). If debug access to the target device is required when the Board Controller is unpowered, this
should be done by connecting directly to the appropriate breakout pins.
The pinout of the connector follows that of the standard ARM Cortex Debug+ETM 19-pin connector. The pinout is described in detail
below. Even though the connector has support for both JTAG and ETM Trace, it does not necessarily mean that the kit or the on-board
target device supports this.
1 2
4
8
6
10
3
5
9
12
13 14
11
15 16
17 18
20
19
TMS / SWDIO / C2D
TCK / SWCLK / C2CK
TDO / SWO
TDI / C2Dps
TRACECLK
TRACED0
TRACED1
TRACED2
TRACED3
RESET / C2CKps
GND
NC
NC
GND
GND
GND
7
GND
VTARGET
Cable Detect
NC
Figure 4.4. Debug Connector
Note: The pinout matches the pinout of an ARM Cortex Debug+ETM connector, but these are not fully compatible as pin 7 is physically
removed from the Cortex Debug+ETM connector. Some cables have a small plug that prevent them from being used when this pin is
present. If this is the case, remove the plug, or use a standard 2x10 1.27 mm straight cable instead.
Table 4.2. Debug Connector Pin Descriptions
Pin number(s) Function Description
1 VTARGET Target voltage on the debugged application.
2 TMS / SDWIO / C2D JTAG test mode select, Serial Wire data or C2 data
4 TCK / SWCLK / C2CK JTAG test clock, Serial Wire clock or C2 clock
6 TDO/SWO JTAG test data out or Serial Wire Output
8 TDI / C2Dps JTAG test data in, or C2D "pin sharing" function
10 RESET / C2CKps Target device reset, or C2CK "pin sharing" function
12 TRACECLK Not connected
14 TRACED0 Not connected
16 TRACED1 Not connected
18 TRACED2 Not connected
20 TRACED3 Not connected
9 Cable detect Connect to ground
11, 13 NC Not connected
3, 5, 15, 17, 19 GND Ground
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Connectors
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4.4 Simplicity Connector
The Simplicity Connector featured on the Wireless Starter Kit Mainboard enables advanced debugging features such as the AEM, the
Virtual COM port and the Packet Trace Interface to be used towards an external target. The pinout is illustrated in the figure below.
VMCU 1
33V3
5
5V
15
GND
13
GND
11
GND
9
GND
7
GND
17
Board ID SCL
19
Board ID SDA
2Virtual COM TX / MOSI
4Virtual COM RX / MISO
6Virtual COM CTS / SCLK
8Virtual COM RTS / CS
10 Packet Trace 0 Sync
12 Packet Trace 0 Data
14 Packet Trace 0 Clock
16 Packet Trace 1 Sync
18 Packet Trace 1 Data
20 Packet Trace 1 Clock
Figure 4.5. Simplicity Connector
Note: Current drawn from the VMCU voltage pin is included in the AEM measurements, while the 3V3 and 5V voltage pins are not. To
monitor the current consumption of an external target with the AEM, unplug the WSTK Radio Board from the WSTK Mainboard to avoid
that the Radio Board current consumption is added to the measurements.
Table 4.3. Simplicity Connector Pin Descriptions
Pin number(s) Function Description
1 VMCU 3.3 V power rail, monitored by the AEM
3 3V3 3.3 V power rail
5 5V 5 V power rail
2 VCOM_TX_MOSI Virtual COM Tx/MOSI
4 VCOM_RX_MISO Virtual COM Rx/MISO
6 VCOM_CTS_SCLK Virtual COM CTS/SCLK
8 VCOM_RTS_CS Virtual COM RTS/CS
10 PTI0_SYNC Packet Trace 0 Sync
12 PTI0_DATA Packet Trace 0 Data
14 PTI0_CLK Packet Trace 0 Clock
16 PTI1_SYNC Packet Trace 1 Sync
18 PTI1_DATA Packet Trace 1 Data
20 PTI1_CLK Packet Trace 1 Clock
17 EXT_ID_SCL Board ID SCL
19 EXT_ID_SDA Board ID SDA
7, 9, 11, 13, 15 GND Ground
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5. Power Supply and Reset
5.1 Radio Board Power Selection
The EFR32 on a Wireless Starter Kit can be powered by one of these sources:
• the debug USB cable;
• a 3V coin cell battery; or
• a USB regulator on the Radio Board (for devices with USB support only).
The power source for the radio board is selected with the slide switch in the lower left corner of the Wireless STK Mainboard. Figure
5.1 Power Switch on page 9 shows how the different power sources can be selected with the slide switch.
VMCU
AEM
USB
BAT
USB Mini-B
Connector
Advanced
Energy
Monitor
3 V Lithium Battery
(CR2032)
BAT
USB
AEM
LDO
EFR32
5 V 3.3 V
Figure 5.1. Power Switch
With the switch in the AEM position, a low noise 3.3 V LDO on the WSTK Mainboard is used to power the Radio Board. This LDO is
again powered from the debug USB cable. The Advanced Energy Monitor is now also connected in series, allowing accurate high
speed current measurements and energy debugging/profiling.
With the switch in the USB position, radio boards with USB-support can be powered by a regulator on the radio board itself. BRD4150A
does not contain an USB regulator, and setting the switch in the USB postition will cause the EFR32 to be unpowered.
Finally, with the switch in the BAT position, a 20 mm coin cell battery in the CR2032 socket can be used to power the device. With the
switch in this position no current measurements are active. This is the recommended switch position when powering the radio board
with an external power source.
Note: The current sourcing capabilities of a coin cell battery might be too low to supply certain wireless applications.
Note: The Advanced Energy Monitor can only measure the current consumption of the EFR32 when the power selection switch is in
the AEM position.
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Power Supply and Reset
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5.2 Board Controller Power
The board controller is responsible for important features such as the debugger and the Advanced Energy Monitor, and is powered
exclusively through the USB port in the top left corner of the board. This part of the kit resides on a separate power domain, so a differ-
ent power source can be selected for the target device while retaining debugging functionality. This power domain is also isolated to
prevent current leakage from the target power domain when power to the Board Controller is removed.
The board controller power domain is exclusively supplied by the J-Link USB cable, and is not influenced by the position of the power
switch.
The kit has been carefully designed to keep the board controller and the target power domains isolated from each other as one of them
powers down. This ensures that the target EFR32 device will continue to operate in the USB and BAT modes.
5.3 EFR32 Reset
The EFR32 Wireless SoC can be reset by a few different sources:
• A user pressing the RESET button.
• The on-board debugger pulling the #RESET pin low.
• An external debugger pulling the #RESET pin low.
In addition to the reset sources mentioned above, the Board Controller will also issue a reset to the EFR32 when booting up. This
means that removing power to the Board Controller (plugging out the J-Link USB cable) will not generate a reset, but plugging the cable
back in will, as the Board Controller boots up.
UG178: EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board
Power Supply and Reset
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6. Peripherals
The starter kit has a set of peripherals that showcase some of the features of the EFR32.
Be aware that most EFR32 I/O routed to peripherals are also routed to the breakout pads. This must be taken into consideration when
using the breakout pads for your application.
6.1 Push Buttons and LEDs
The kit has two user push buttons marked PB0 and PB1. They are connected directly to the EFR32, and are debounced by RC filters
with a time constant of 1 ms. The buttons are connected to pins PF6 and PF7.
The kit also features two yellow LEDs marked LED0 and LED1, that are controlled by GPIO pins on the EFR32. The LEDs are connec-
ted to pins PF4 and PF5 in an active-high configuration.
PF5 (GPIO)
User Buttons
& LEDs
UIF_LED0
UIF_LED1
UIF_PB0
UIF_PB1
PF6 (GPIO)
PF7 (GPIO)
PF4 (GPIO)
EFR32
Figure 6.1. Buttons and LEDs
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Peripherals
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6.2 Memory LCD-TFT Display
A 1.28-inch SHARP Memory LCD-TFT is available on the kit to enable interactive applications to be developed. The display has a high
resolution of 128 by 128 pixels, and consumes very little power. It is a reflective monochrome display, so each pixel can only be light or
dark, and no backlight is needed in normal daylight conditions. Data sent to the display is stored in the pixels on the glass, which means
no continous refreshing is required to maintain a static image.
The display interface consists of an SPI-compatible serial interface and some extra control signals. Pixels are not individually addressa-
ble, instead data is sent to the display one line (128 bits) at a time.
The Memory LCD-TFT display is shared with the kit Board Controller, allowing the Board Controller application to display useful infor-
mation when the user application is not using the display. The user application always controls ownership of the display with the
DISP_ENABLE signal:
• DISP_ENABLE = LOW: The Board Controller has control of the display
• DISP_ENABLE = HIGH: The user application (EFR32) has control of the display
Power to the display is sourced from the target application power domain when the EFR32 controls the display, and from the Board
Controller's power domain when the DISP_ENABLE line is low. Data is clocked in on DISP_SI when DISP_CS is high, and the clock is
sent on DISP_SCLK. The maximum supported clock speed is 1.1 MHz.
DISP_COM is the "COM Inversion" line. It must be pulsed periodically to prevent static build-up in the display itself. Please refer to the
display application information for details on driving the display:
http://www.sharpmemorylcd.com/1-28-inch-memory-lcd.html
PC8 (US1_CLK#11)
PC6 (US1_TX#11)
PD14 (US1_CS#19)
PD13 (LETIMER0)
PD15 (GPIO)
EFR32
0: Board Controller controls display
1: EFR32 controls display
Figure 6.2. 128x128 Pixel Memory LCD
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Peripherals
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6.3 Serial Flash
The BRD4150A radio board is equipped with an 8 Mbit Macronix MX25R SPI flash that is connected directly to the EFR32 Mighty
Gecko. Figure 6.3 Radio Board Serial Flash on page 13 shows how the serial flash is connected to the EFR32.
PC8 (US1_CLK#11)
PC6 (US1_TX#11)
PC7 (US1_RX#11)
PA4 (US1_CS#1)
EFR32
MX25R8035F
SCLK
MOSI
MISO
SCS
VMCU
VDD
8 Mbit
Figure 6.3. Radio Board Serial Flash
The MX25R series are ultra low power serial flash devices, so there is no need for a separate enable switch to keep current consump-
tion down. However, it is important that the flash is always put in deep power down mode when not used. This is done by issuing a
command over the SPI interface. In deep power down, the MX25R typically adds approximately 100 nA to the radio board current con-
sumption.
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6.4 Si7021 Relative Humidity and Temperature Sensor
The Si7021 I2C relative humidity and temperature sensor is a monolithic CMOS IC integrating humidity and temperature sensor ele-
ments, an analog-to-digital converter, signal processing, calibration data, and an I2C Interface. The patented use of industry-standard,
low-K polymeric dielectrics for sensing humidity enables the construction of low-power, monolithic CMOS Sensor ICs with low drift and
hysteresis, and excellent long term stability.
The humidity and temperature sensors are factory-calibrated and the calibration data is stored in the on-chip non-volatile memory. This
ensures that the sensors are fully interchangeable, with no recalibration or software changes required.
The Si7021 is available in a 3x3 mm DFN package and is reflow solderable. It can be used as a hardware- and software-compatible
drop-in upgrade for existing RH/ temperature sensors in 3x3 mm DFN-6 packages, featuring precision sensing over a wider range and
lower power consumption. The optional factory-installed cover offers a low profile, convenient means of protecting the sensor during
assembly (e.g., reflow soldering) and throughout the life of the product, excluding liquids (hydrophobic/oleophobic) and particulates.
The Si7021 offers an accurate, low-power, factory-calibrated digital solution ideal for measuring humidity, dew-point, and temperature,
in applications ranging from HVAC/R and asset tracking to industrial and consumer platforms.
The I2C bus used for the Si7021 is shared with the Expansion Header. The temperature sensor is normally isolated from the I2C line. To
use the sensor, PD15 must be set high. When enabled, the sensor's current consumption is included in the AEM measurements.
SENSOR_ENABLE
0: I2C lines are isolated, sensor is not powered
1: Sensor is powered and connected
PC10 (I2C0_SCL#14)
PC11 (I2C0_SDA#16)
PD15 (GPIO)
SENSOR_I2C_SDA
SENSOR_I2C_SCL
VMCU
VDD
SCL
SDA Temperature
& Humidity
Sensor
EFR32
Si7021
Figure 6.4. Si7021 Relative Humidity and Temperature Sensor
Please refer to the Silicon Labs web pages for more information: http://www.silabs.com/humidity-sensors
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6.5 Virtual COM Port
An asynchronous serial connection to the board controller is provided for application data transfer between a host PC and the target
EFR32. This eliminates the need for an external serial port adapter.
VCOM_ENABLE
PA0 (US0_TX#0)
PA1 (US0_RX#0)
PA5 (GPIO)
VCOM_RX
VCOM_TX
Board
Controller
EFR32
USB Host
PC
Isolation & Level Shift
PA2 (US0_CTS#30)
PA3 (US0_RTS#30)
VCOM_CTS
VCOM_RTS
ETH
or
Figure 6.5. Virtual COM Port Interface
The Virtual COM port consists of a physical UART between the target device and the board controller, and a logical function in the
board controller that makes the serial port available to the host PC over USB or Ethernet. The UART interface consists of four pins and
an enable signal.
Table 6.1. Virtual COM Port Interface Pins
Signal Description
VCOM_TX Transmit data from the EFR32 to the board controller
VCOM_RX Receive data from the board controller to the EFR32
VCOM_CTS Clear to Send hardware flow control input, asserted by the board controller when it is ready to receive more data
VCOM_RTS Request to Send hardware flow control output, asserted by the EFR32 when it is ready to receive more data
VCOM_ENABLE Enables the VCOM interface, allowing data to pass through to the board controller.
The parameters of the serial port, such as baud rate or flow control, can be configured using the admin console. The default settings
depends on which radio board is used with the Wireless Starter Kit Mainboard. Please see 10. Device Connectivity for more details.
Note: The VCOM port is only available when the board controller is powered, which requires the J-Link USB cable to be inserted.
UG178: EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board
Peripherals
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7. Board Controller
The Wireless Starter Kit Mainboard contains a microcontroller separate from the EFR32 Mighty Gecko that is responsible for some of
the advanced kit features provided. This microcontroller is referred to as the "Board Controller", and is not programmable by the user.
The board controller acts as an interface between the host PC and the target device on the radio board, as well as handling some
house-keeping functions on the board.
Some of the kit features actively managed by the board controller are:
• The , which can flash and debug both on-board and external targets.
• The Advanced Energy Monitor, which provides real-time energy profiling of the user application.
• The Packet Trace Interface , which is used in conjunction with PC software to provide detailed insight into an active radio network.
• The Virtual COM Port and Virtual UART interfaces, which provide ways to transfer application data between the host PC and the
target processor.
• The Admin Console, which provides configuration of the various board features.
Silicon Labs publishes updates to the board controller firmware in form of firmware upgrade packages. These updates may enable new
features or fix issues. See 11.2 Firmware Upgrades for details on firmware upgrade.
7.1 Admin Console
The admin console is a command line interface to the board controller on the kit. It provides functionality for configuring the kit behavior
and retreiving configuration and operational parameters.
■Connecting
The SLWRB4150A must be connected to Ethernet using the Ethernet connector in the top left corner of the mainboard for the admin
console to be available. See ● Ethernet Interface for details on the Ethernet connectivity.
Connect to the Admin Console by opening a telnet connection to the kit's IP address, port number 4902.
When successfully connected, a WSTK> prompt is displayed.
UG178: EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board
Board Controller
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■Built-in Help
The admin console has a built in help system which is accessed by the help command. The help command will print a list of all top
level commands:
WSTK> help
*************** Root commands ****************
aem AEM commands [ calibrate, current, dump, ... ]
boardid Commands for board ID probe. [ list, probe ]
dbg Debug interface status and control [ info, mode,]
dch Datachannel control and info commands [ info ]
discovery Discovery service commands.
net Network commands. [ dnslookup, geoprobe, ip ]
pti Packet trace interface status and control [ config, disable, dump, ... ]
quit Exit from shell
sys System commands [ nickname, reset, scratch, ... ]
target Target commands. [ button, flashwrite, go, ... ]
time Time Service commands [ client, server ]
user User management functions [ login,]
The help command can be used in conjunction with any top level command to get a list of sub-commands with description. For exam-
ple, pti help will print a list of all available sub-commands of pti:
WSTK> pti help
*************** pti commands ****************
config Configure packet trace
disable Disable packet trace
dump Dump PTI packets to the console as they come
enable Enable packet trace
info Packet trace state information
This means that running pti enable will enable packet trace.
■Command Examples
PTI Configuration
pti config 0 efruart 1600000
Configures PTI to use the "EFRUART" mode at 1.6 Mb/s.
Serial Port Configuration
serial config vcom handshake enable
Enables hardware handshake on the VCOM UART connection.
UG178: EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board
Board Controller
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8. Advanced Energy Monitor
8.1 Introduction
Any embedded developer seeking to make his embedded code spend as little energy as the underlying architecture supports, needs
tools to easily and quickly discover inefficiencies in the running application.
This is what the Simplicity Energy Profiler is designed to do. It will in real-time graph and log current as a function of time while correlat-
ing this to the actual target application code running on the EFR32. There are multiple features in the profiler software that allows for
easy analysis, such as markers and statistics on selected regions of the current graph or aggregate energy usage by different parts of
the application.
8.2 Theory of Operation
The Advanced Energy Monitor (AEM) circuitry on the board is capable of measuring current signals in the range of 0.1 µA to 95 mA,
which is a dynamic range of alomst 120 dB. It can do this while maintaining approximately 10 kHz of current signal bandwidth. This is
accomplished through a combination of a highly capable current sense amplifier, multiple gain stages and signal processing within the
kit's board controller before the current sense signal is read by a host computer for display and/or storage.
The current sense amplifier measures the voltage drop over a small series resistor, and the gain stage further amplifies this voltage with
two different gain settings to obtain two current ranges. The transition between these two ranges occurs around 250 µA.
The current signal is combined with the target processor's Program Counter (PC) sampling by utilizing a feature of the ARM CoreSight
debug architecture. The ITM (Instrumentation Trace Macrocell) block can be programmed to sample the MCU's PC at periodic intervals
(50 kHz) and output these over SWO pin ARM devices. When these two data streams are fused and correlated with the running appli-
cation's memory map, an accurate statistical profile can be built, that shows the energy profile of the running application in real-time.
At kit power-up or on a power-cycle, and automatic AEM calibration is performed. This calibration compensates for any offset errors in
the current sense amplifiers.
EFR32
LDO
Peripherals
AEM
Processing
Figure 8.1. Advanced Energy Monitor
UG178: EFR32MG 2400/868 MHz 13 dBm Dual Band Radio Board
Advanced Energy Monitor
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8.3 AEM Accuracy and Performance
The AEM is capable of measuring currents in the range of 0.1 µA to 95 mA. For currents above 250 µA, the AEM is accurate within 0.1
mA. When measuring currents below 250 µA, the accuracy increases to 1 µA. Even though the absolute accuracy is 1 µA in the sub
250 µA range, the AEM is able to detect changes in the current consumption as small as 100 nA.
The AEM current sampling rate is 10 kHz.
Note: The AEM circuitry only works when the kit is powered and the power switch is in the AEM position.
8.4 Usage
The AEM data is collected by the board controller and can be displayed by the Energy Profiler, available through Simplicity Studio. By
using the Energy Profiler, current consumption and voltage can be measured and linked to the actual code running on the EFR32 in
realtime.
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Advanced Energy Monitor
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