Silicon Labs EZR32LG 868MHz Wireless Starter Kit User Manual

1. Introduction

The WSTK6200 is an excellent starting point to get familiar with the EZR32 Leopard Gecko Wireless Microcontrollers. The Wireless Starter Kit Mainboard (BRD4001) features an on-board J-Link debugger, an Advanced Energy Monitor (AEM) for real-time current and voltage monitoring, a Virtual COM port interface, and access to the Packet Trace Interface (PTI). The mainboard is paired with an EZR32 Leopard Gecko radio board. The kit provides all necessary tools for developing a Silicon Labs wireless application.

1.2 Kit Content

The following items are included in the box:

• 2x BRD4001A Wireless Starter Kit Mainboards
• 2x BRD4502A EZR32 Leopard Gecko 868 MHz WSTK Radio Boards
• 2x 868 MHz antennas with SMA connector
• 2x CR2032 Lithium batteries
• 2x USB Type A to USB Mini-B cables
• 2x USB Type A to USB Micro-B cables

A visual representation of the kit contents is provided in Figure 1.1.

1.3 Getting Started

Detailed instructions for getting started with the WSTK6200 are available on the Silicon Labs Simplicity web pages:

http://www.silabs.com/simplicity

2. Kit Block Diagram

The block diagram illustrates the connectivity of the EZR32LG 868MHz Wireless Starter Kit. It shows the interaction between the RJ-45 Ethernet Connector, Board Controller, USB Mini-B Connector, Simplicity Connector, Debug Connector, Expansion Header, USB Micro-B Connector, and SMA Connector, all connected to the central EZR32 Wireless MCU. Key interfaces like UART, AEM, Packet Trace, Debug, SPI, I2C, GPIO, and RF are depicted. The diagram also highlights integrated peripherals such as the 128x128 pixel Memory LCD, User Buttons & LEDs, and the Temperature & Humidity Sensor.

3. Kit Hardware Layout

The EZR32LG 868MHz Wireless Starter Kit features an on-board USB and Ethernet J-Link Debugger, SoC/Radio pin access headers, and the EZR32 Radioboard. Peripherals include the Si7021 Humidity and Temperature Sensor, a USB-serial-port with Packet-trace and Advanced Energy Monitoring capabilities, an ultra-low power 128x128 pixel memory LCD with buttons and LEDs, and an EXP-header for expansion boards. An ARM Coresight 19-pin trace/debug header is also present. Power can be supplied via USB or a CR2032 coin cell battery.

The kit comprises two BRD4001 Wireless Starter Kit Mainboards and two BRD4502A plug-in radio boards. Key specifications include:

• Wireless MCU: EZR32LG330F256R60G
• CPU core: ARM Cortex-M3
• Flash memory: 256 kB
• RAM: 32 kB
• Transceiver: EZRadioPRO Sub-GHz transceiver
• Operation frequency: 868 MHz
• Transmit power: 13 dBm
• Antenna connector: Single SMA connector
• Crystals: LFXO (32.768kHz), HFXO (48 MHz), RF (26 MHz)
• USB: Full speed USB 2.0 (12 Mbps)

4. Power Supply and Reset

4.1 MCU Power Selection

The EZR32 Leopard Gecko MCU can be powered by three sources:

• The debug USB cable
• The EZR32's internal USB regulator
• A 3V coin cell battery

A slide switch selects the power source. In the AEM position, a 3.3V LDO powered by the debug USB cable powers the MCU, enabling the Advanced Energy Monitor. In the USB position, the EZR32's internal regulator powers the chip for USB device applications. In the BAT position, a CR2032 coin cell battery powers the device, though its current sourcing capability may be limited.

Note: The Advanced Energy Monitor functions only when the power switch is in the AEM/DBG position.

4.2 Board Controller Power

The Board Controller, responsible for the debugger and AEM, is powered exclusively via the USB port. This power domain is isolated from the MCU domain.

4.3 Backup Power Domain

A backup capacitor is provided for the EZR32's backup power domain, allowing a small part of the MCU to operate from the capacitor when other power sources are removed. This enables low-power clock applications for extended periods.

4.4 MCU Reset

The EZR32 MCU can be reset via:

• The user-pressed RESET button.
• The on-board debugger pulling the #RESET pin low.
• An external debugger pulling the #RESET pin low.

4.5 Board Controller Reset

The Board Controller can be reset by removing and re-inserting the J-Link USB cable. This action also triggers a reset to the EZR32 via the on-board debugger.

5. Peripherals

5.1 Push Buttons and LEDs

The kit includes two user push buttons (PB0, PB1) connected to pins PC8 and PC9, debounced by RC filters. Two yellow LEDs (LED0, LED1) are controlled by GPIO pins PC10 and PC11, respectively, in an active-high configuration.

5.2 Memory LCD-TFT Display

A 1.28-inch SHARP Memory LCD-TFT display (128x128 pixels, monochrome) is integrated for interactive applications. It requires minimal power and no backlight in daylight. The display uses an SPI-compatible serial interface and can be shared with the Board Controller. User application control is managed via EFM_DISP_SELECT (PA8). Power is enabled by EFM_DISP_PWR (PA10). Data transfer uses EFM_DISP_MOSI (PD7), EFM_DISP_CS (PE11), and EFM_DISP_SCLK (PC15) at up to 1.1 MHz. EFM_DISP_COM (PE10) is used for COM inversion. For detailed driving information, refer to:

http://www.sharpmemorylcd.com/1-28-inch-memory-lcd.html

5.3 Backup Domain Capacitor

A 33mF super capacitor is provided for the EZR32's backup power domain, connected via a 100-ohm series resistor to the BU_VIN pin. This capacitor can power a clock application using the low frequency crystal oscillator (LFXO) for over 8 hours due to the EZR32's low backup power consumption (400nA).

5.4 USB Micro-B Connector

The radio board features a USB Micro-B connector for USB Device mode operation, connected directly to the EZR32.

5.5 Si7021 Relative Humidity and Temperature Sensor

The Si7021 is a monolithic CMOS IC providing humidity and temperature sensing via an I2C interface. It features industry-standard, low-K polymeric dielectrics for humidity sensing, offering low drift and hysteresis. The sensor is factory-calibrated and available in a 3x3 mm DFN package. It can serve as a drop-in upgrade for existing sensors. The I2C bus is shared with the Expansion Header; PF8 must be set high to enable the sensor and include its consumption in AEM measurements.

6. Advanced Energy Monitor

6.1 Introduction

The Simplicity Energy Profiler is designed to help embedded developers identify and resolve energy inefficiencies in their applications by graphing and logging current consumption in real-time, correlated with application code execution.

6.2 Advanced Energy Monitor - Theory of Operation

The AEM circuitry measures current from 0.1uA to 150mA with a 10kHz bandwidth. It uses a current sense amplifier, multiple gain stages, and board controller signal processing. The current signal is combined with Program Counter (PC) sampling via ARM CoreSight and ITM for detailed energy profiling. Automatic calibration compensates for offset errors.

6.3 AEM Accuracy and Performance

The AEM measures currents between 0.1 µA and 95 mA. Accuracy is within 0.1 mA for currents above 250 µA and 1 µA for currents below 250 µA. It can detect current changes as small as 100 nA. The sampling rate is 10000 Hz. The AEM operates when the kit is powered and the switch is in the AEM/DBG position.

6.4 Usage

AEM data is collected by the board controller and visualized using the Energy Profiler in Simplicity Studio, allowing real-time measurement and correlation of current consumption and voltage with the running code.

7. Board Controller

The board controller manages tasks like debugging and the Advanced Energy Monitor, communicating with the EZR32 via a UART connection. It is enabled by VCOM_ENABLE (PA12) and uses VCOM_TX (PB3) and VCOM_RX (PB4). Board Support Package library functions are available for querying AEM data. The board controller requires USB power.

7.1 VCOM

Virtual COM (VCOM) enables serial communication through:

• A virtual USB COM port (CDC driver).
• TCP/IP via port 4901.
• The expansion header.

VCOM operates in two modes: Transparent mode for raw byte stream forwarding, and BSP-mode for utilizing BSP functionality with VCOM access.

8. Board Support Package

8.1 Application Programming Interface

The Board Support Package (BSP) provides C source and header files for accessing board features. It uses EZR32 peripheral USART2 for communication with the board controller. Example API functions include BSP_LedClear and BSP_LedSet.

8.2 Example Applications

Example programs utilizing the BSP are located in the kits/EZR32LG_WSTK6200/examples folder within the Simplicity installation directory.

8.3 How to include in your own applications

To integrate the BSP into your application:

1. Define the correct part number (e.g., EZR32LG330F256R60G) as a preprocessor symbol.
2. Include EFM32_CMSIS-files (startup_efm32.s, system_efm32.c, core_cm3.c).
3. Add all BSP package .c-files.
4. Configure include paths for CMSIS and BSP directories.
5. Call BSP_Init() early in the startup sequence.

9. Connectors

9.1 Radio Board breakout pads

The mainboard provides breakout pads for most EZR32 pins, accessible via a 2.54mm pitch pin header. These pads map to the EZR32 Leopard Gecko Radio Board pins.

9.2 Debug Connector (DBG)

This connector is used for debug input and output. It features pins for VTARGET, SWDIO/TMS, SWCLK/TCK, SWO/TDO, TDI, #RESET, TRACECLK, TRACE_DATA[0-3], and Cable Detect. While pin-compatible with ARM Cortex Debug+ETM connectors, pin 7 is physically removed. The kit lacks an onboard trace emulator, and EZR32 devices do not support JTAG.

9.3 Simplicity Connector

The Simplicity Connector facilitates advanced debugging features like AEM, Virtual COM, and Packet Trace for external targets. It provides access to VMCU, 3V3, 5V power rails, VCOM signals, and Packet Trace signals.

9.4 Expansion header

A 20-pin expansion header allows connection of peripherals or plugin boards, exporting VMCU, 3V3, and 5V power rails along with various I/O pins and alternate functions of the EZR32.

10. Integrated Development Environments

Simplicity Studio provides a unified environment for development. It includes various IDEs and tools:

• IAR Embedded Workbench for ARM: An evaluation version is included on the WSTK6200 CD.
• Atollic TrueSTUDIO for ARM: Project files are available in the 'atollic' subfolder.
• Rowley Associates - CrossWorks for ARM: Project files are available in the 'rowley' subfolder.
• CodeSourcery - Sourcery G++: Contains Makefiles for the Sourcery G++ environment.
• Keil - MDK-ARM: Project files are available in the 'arm' subfolder.

Simplicity Studio also offers example projects for the Starter Kit. To run examples:

1. Connect the kit to the PC via the DBG USB connector.
2. Set the power switch to AEM.
3. Refresh detected hardware and select the WSTK6200.
4. Navigate to [Software Examples] under [Software and Kits].
5. Select the WSTK6200 kit and the desired example.
6. Click [Finish], then [Debug] to build and download code.
7. Follow on-screen instructions for hardware setup.
8. Click [Resume] to run the example.

11. Kit Manager and Upgrades

11.1 Kit Manager Operation

The Kit Manager, part of Simplicity Studio, allows programming the EZR32, upgrading the kit, and managing device lock states.

11.2 Firmware Upgrades

Firmware can be upgraded automatically by Simplicity Studio on startup or manually via the Kit Manager's [Update Kit] section using a `.emz` file.

12. Schematics, Assembly Drawings and BOM

Schematics, assembly drawings, and Bill of Materials (BOM) for the EZR32LG 868MHz Wireless Starter Kit are accessible through Simplicity Studio after installing the kit documentation package.

13. Kit Revision History and Errata

13.1 Revision History

Kit revisions are indicated on the box label. Previous revisions include A01 (updated BRD4001) and A00 (initial revision).

13.2 Errata

This section would list any known errata for the kit.

14. Document Revision History