Silicon Laboratories UG291 User Manual

UG291: WGM110 Wi-Fi® Expansion Kit
User's Guide

The WGM110 Wi-Fi Expansion Kit is an excellent way to explore
and evaluate the WGM1

10 Wi-Fi Module with an EFM32 MCU for

your embedded application.

The kit contains a Wireless Expansion Board (BRD8016A) and a WGM110 Wi-Fi Mod­ule Radio Board (BRD4320A). The WGM110 Wi-Fi Module is an easy to use and easy
to interface Wi-Fi Network Co-Processor (NCP). Most of the associated complexity of
Wi-Fi and the protocol stack is offloaded to the module and allows for easy Wi-Fi inte­gration into any embedded system.

The kit easily integrates and brings Wi-Fi connectivity to a compatible Silicon Labs
MCU Starter Kit through the expansion header. The Wireless Expansion Board has al­so been designed after the Raspberry Pi Hardware Attached on Top (HAT) board speci­fication, allowing the WGM110 Wi-Fi Expansion Kit to connect to a Raspberry Pi.

WIRELESS EXPANSION BOARD FEATURES

• EXP connector for interfacing Silicon
Labs Starter Kits

• Common feature set, including SPI,
UAR

T, and I2C

• Allows board detection and
identification

• Radio Board connectors for inserting
Silicon Labs Wireless Radio Boards

• Mini Simplicity debug connector

• Supports programming and debugging
the module firmware

• LDO for high-power radio boards

• Raspberry Pi compatible HAT

• Unpopulated header

• HAT EEPROM for identification

WGM110 WI-FI MODULE RADIO BOARD FEATURES

• WGM110A Wizard Gecko Wi-Fi Module

• Integrated chip antenna

802.11b/g/n compliant

•

• TX power: 16 dBm

• RX sensitivity: -98 dBm

• CPU core: 32-bit ARM® Cortex-M3

• Flash memory: 1 MB

• RAM: 128 kB

• Module certification: FCC, IC, Japan
and Korea

• CE compliant

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Table of Contents

1. Introduction ................................

1.1 Kit Contents ..............................3

1.2 Getting Started .............................3

3

2. Hardware Overview .............................4

2.1 Hardware Layout .............................4

3. Wi-Fi Expansion Kit .............................5

3.1 Board Setup ..............................5

3.2 Board Identification ............................6

3.3 Host Interfaces .............................6

3.3.1 UART ..............................6

3.3.2 SPI ...............................7

3.3.3 STK Pin Mapping...........................8

4. Wireless EXP Board .............................9

4.1 EXP Header ..............................9

4.1.1 Pass-through Expansion Header .....................10

4.1.2 Expansion Header Pinout ........................10

4.2 Raspberry Pi Connector ..........................11

4.2.1 Raspberry Pi Connector Pinout ......................12

4.3 Mini Simplicity Connector ..........................13

4.3.1 Mini Simplicity Connector Pinout .....................14

4.4 Power Supply ..............................15

5. Reconfiguring the Wi-Fi Module Firmware ................... 17

5.1 Building the Module Firmware ........................17

5.2 Programming the Module Firmware ......................18

6. Schematics, Assembly Drawings, and BOM ................... 20

7. Kit Revision History ............................ 21

7.1 SLEXP4320A Revision History ........................21

8. Document Revision History ......................... 22

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UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Introduction

1. Introduction

The WGM110 Wi-Fi Expansion Kit (OPN: SLEXP4320A) contains a Wireless Expansion Board (BRD8016A) and a WGM110 Wi-Fi
Module Radio Board (BRD4320A) that plug directly into each other. The core of the kit is a WGM110 Wizard Gecko Wi-Fi Module which
makes this kit an excellent starting point for adding Wi-Fi connectivity to a compatible Silicon Labs MCU Starter Kit.

The kit connects and works out-of-the box by inserting it into the expansion header of one of these Silicon Labs MCU Starter Kits
(STKs):

• EFM32 Pearl Gecko PG12 Starter Kit - SLSTK3402A

• EFM32 Pearl Gecko PG1 Starter Kit - SLSTK3401A

• EFM32 Giant Gecko GG11 Starter Kit - SLSTK3701A

Note: The kit is sold without a Silicon Labs MCU STK.

The firmware and demo that is available with the kit targets applications where the MCU on the STK serves as a host that drives the
application and tells the WGM110 Wi-Fi Module what to do. The picture below shows the kit connected to a Silicon Labs MCU STK
through the Expansion Header.

Figure 1.1. WGM110 Wi-Fi Expansion Kit Connected to a Silicon Labs MCU STK

Although the main connectivity path for the kit is to a Silicon Labs MCU STK through the Expansion Header, the kit can also connect to
a Raspberry Pi and function as a Raspberry Pi HAT

Note: Do not connect the kit to both a Silicon Labs MCU STK and a Raspberry Pi at the same time.

1.1 Kit Contents

The following items are included in the box:

• 1x Wireless Expansion Board (BRD8016A)

• 1x WGM110 Wi-Fi Module (BRD4320A)

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-efm32-wifi

. To do so, a dual row, female socket, 0.1" pitch connector must be soldered in.

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2. Hardware Overview

EXP-header for
Starter Kits

Power switch

Pass-through EXP-header

Not mounted

Mini Simplicity
connector

Raspberry Pi connector

Not mounted

Radio Board connectors

Wireless

Expansion Board

WGM110 Wi-Fi

Module Radio Board

WGM110 Wi-Fi Module

WGM110 Wi-Fi
Expansion Kit

Wireless Expansion Board

WGM110 Wi-Fi
Module Radio Board

2.1 Hardware Layout

The layout of the WGM110 Wi-Fi Expansion Kit is shown in the figure below.

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Hardware Overview

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Figure 2.1. WGM110 Wi-Fi Expansion Kit Hardware Layout

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wi-Fi Expansion Kit

3. Wi-Fi Expansion Kit

The Wizard Gecko WGM110 is an all-inclusive Wi-Fi Module targeted for applications where good RF performance, low power con­sumption, and easy application development, together with fast time to market, are key requirements. WGM110 has excellent RF per­formance and can provide long range with robust wireless connectivity. The WGM110 Module integrates all of the necessary elements
required for an IoT Wi-Fi application, including an 802.11b/g/n radio, integrated chip antenna, certifications, a microcontroller, Wi-Fi and
IP stacks, an HTTP server, and multiple protocols, such as TCP and UDP.

WGM110 can act as a Wi-Fi client or be used as a Wi-Fi access point, making the provisioning of the device as easy as surfing on the
web. WGM110 can host BGScript end user applications, which means applications can be designed without relying on an external mi­crocontroller. Alternatively, the Wi-Fi Module can run in Network Co-Processor (NCP) mode, leaving the complexity of TCP/IP network­ing to the Module so that the customer’s own host controller can be fully dedicated to processing the customer application tasks.

The Wi-Fi expansion kit provides the ability to pair up the WGM110 Wi-Fi Module with an EFM32 host running the user application,
using the module as a network co-processor. The kit provides the Wireless EXP Board and a WGM110 Wi-Fi Module Radio Board, and
should be used together with a Silicon Labs MCU Starter Kit, such as the EFM32 Pearl Gecko PG12 STK. NCP mode of operation is
the primary focus of this kit. For standalone application development, the Wizard Gecko Wi-Fi Module Wireless Starter Kit
(SLWSTK6120A) is recommended instead.

Figure 3.1. WGM110 Wi-Fi Module as a Network Co-Processor (NCP)

The WGM110 Wi-Fi Module in the kit is pre-configured as a network co-processor, requiring no additional programming of the module
itself in
interface, over a UART or SPI interface. (UART with RTS/CTS flow control is enabled by default).

All Wi-Fi and network actions are performed through this interface, and the user can focus on developing the application on the host
MCU. The module application programming interface is described in detail in the WGM110 API Reference Manual.

3.1 Board Setup

A detailed quick start guide is described in QSG145: WGM110 SLEXP4320 Wi-Fi Expansion Kit Quick-Start Guide.

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order to be used with an MCU Starter Kit. Wi-Fi functionality is exposed to the host MCU on the Starter Kit through the BGAPI

1. Insert the WGM110 Wi-Fi Module Radio Board into the radio board connectors on the Wireless EXP board.

2. Plug the Wireless EXP Board into the EXP header of the MCU Starter Kit.

3. Place the MCU power switch in the "AEM" position, and the Wireless EXP Board power switch in the "High Power (LDO)" position.

4. Insert the USB cable to power up the kit and connect it to a computer.

3.2 Board Identification

EXP

Header

WGM1

10

Wi-Fi

Module

EXP14 (UAR

T_RX)

EXP12 (UAR

T_TX)

EXP5

EXP3

Ra

spberry Pi HAT

Connector

GPIO15 (UART_RXD0)

GPIO14 (UAR

T_TXD0)

GPIO16

GPIO17

GPIO23

PE10 (US0_TX)

PE1

1 (US0_RX)

PE12 (US0_CTS)

PE13

(US0_RTS)

14

12

5

3

10

8

36

11

RESETn

EXP7

7

16

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wi-Fi Expansion Kit

The Starter

Kit and Wireless EXP board provide identification of all the connected boards. This detection and identification is used by

the Simplicity Studio tool to present the correct documentation and software examples.

The kit is able to detect which radio board is inserted, but requires the board to be inserted at power-on. It is therefore important to
always connect the boards together before inserting the USB cable into the starter kit (powering on the boards).

3.3 Host Interfaces

There are two available host interfaces on the WGM110 Wi-Fi Expansion Kit, one of which can be used to connect the WGM110 Wi-Fi
Module to an external host. The production firmware on the WGM110 Wi-Fi Module uses UART with RTS/CTS flow control as the de­fault host interface. For information on how to reprogram the firmware on the WGM110 Wi-Fi Module, see Section 5. Reconfiguring the

Wi-Fi Module Firmware.

3.3.1 UART

UART with RTS/CTS flow control is enabled by default on the production firmware of the WGM110 Wi-Fi Module. The UART peripheral
routing is illustrated in the figure below.

Figure 3.2. UART Peripheral Routing on the WGM110 Wi-Fi Expansion Kit

The table below shows the features of the UART host interface. The WGM110 Wi-Fi Module
under default value.

Table 3.1. UART Host Interface Features and Default Values

Parameter Features / Supported

UART baud rate 9600 bps - 6 Mbps 115200 Kbps

Flow control RTS/CTS Enabled

Data bits 8 or 9 8

Parity none, odd, even None

Stop bits 1 or 2 1

Host protocol BGAPI serial protocol BGAPI serial protocol

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Ranges

comes programmed with the settings listed

Default Value

EXP Header

WGM1

10

Wi-Fi

Module

EXP4 (SPI_MOSI)

EXP6 (SPI_MISO)

EXP8 (SPI_SCLK)

EXP10 (SPI_CS)

GPIO10

(SPI_MOSI)

GPIO19

(SPI_MISO)

G

PIO11 (SPI_SCLK)

GPIO8 (SPI_CE0_N)

Ra

spberry Pi HAT

Connector

PD0 (US1_TX)

PD1 (US1_RX)

PD2 (US1_CLK)

PD3 (US1_CS)

4

6

8

10

19

21

23

24

P

A2 (Notify)

EXP1

1

GPIO4

7

11

RESETn EXP7

7

16

GPIO23

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wi-Fi Expansion Kit

3.3.2 SPI

one of two host interfaces available on the Wireless Expansion Board. In order to use SPI as the connection between the

SPI is
WGM110 Wi-Fi Module and a host, the module must be reprogrammed. For more information about how to do this, see Section 3. Wi-

Fi Expansion Kit. The SPI peripheral routing is illustrated in the figure below.

Figure 3.3. SPI Peripheral Routing on the WGM110 Wi-Fi Expansion Kit

The table below shows the features of the SPI host interface.

Parameter Features (Value Ranges)

SPI mode SPI slave

Bit rates 9600 bps - 6 Mbps

Bit order MSB first

Clock polarity and phase Configurable

Host protocol BGAPI serial protocol

Table 3.2. SPI Host Interface Features

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3.3.3 STK Pin Mapping

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wi-Fi Expansion Kit

The pins

connected to the WGM110 Wi-Fi Module will vary based on which Starter Kit is used in the configuration. The software run­ning on the MCU Starter Kit needs to take this into account. The table below shows the pin connections when using either the EFM32
Pearl Gecko PG1 STK or the EFM32 Pearl Gecko PG12 STK.

Table 3.3. MCU Pin Mapping

EXP Header
Pin

Module Func­tion

EFM32 Pearl Gecko PG1 STK EFM32 Pearl Gecko PG12 STK

EXP4 SPI_MOSI PC6 (US1_TX#11) PA6 (US2_TX #1)

EXP6 SPI_MISO PC7 (US1_RX #11) PA7 (US2_RX #1)

EXP8 SPI_SCLK PC8 (US1_CLK #11) PA8 (US2_CLK #1)

EXP10 SPI_CS PC9 (US1_CS #11) PA9 (US2_CS #1)

EXP12 UART_RXD PA0 (US0_TX #0) PD10 (US0_TX #18)

EXP14 UART_TXD PA1 (US0_RX #0) PD11 (US0_RX #18)

EXP3 UART_RTS PA2 (US0_CTS #31) PC9 (US0_CTS #10)

EXP5 UART_CTS PA3 (US0_RTS #31) PD9 (US0_RTS #12)

EXP7 RESET PA4 PB6

Note that the peripheral mapping shown in the right column is just an example. The flexibility of the EFM32 devices allow a number of
different

peripherals to be mapped to these pins. The important thing to note is which pin is used for the connection. The peripheral

usage is a design choice that depends on which other resources are required by the application.

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Expansion

Header

Radio Board

Connectors

Raspberry Pi

Connector

(Not Mounted)

Pass-through

Expansion Header

(Not Mounted)

Mini-Simplicity

Connector

Top Side

12

4

8
6

10

3

5

9
7

12

13

14

11

1516

17

18

20 19

VMCU

SPI_MOSI / PD0

SPI_MISO / PD1

SPI_SCLK / PD2

SPI_CS / PD3

UART_RX / PE11

UART_TX / PE10

I2C_SDA / PE0

5V

3V3

GND

PE13 / UART_RTS

PE12 / UART_CTS

RESETn

PE14

P

A2

Not Connected (NC)

PE1 / I2C_SCL

Board ID SDA
Board ID SCL

Reserved (Board Identification)

WGM1

10 Wi-Fi Module I/O Pin

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

4. Wireless EXP Board

This chapter gives an overview of the Wireless Expansion Board connectivity and power connections.

Wireless EXP Board

4.1 EXP Header

On the
one of Silicon Labs’ supported Starter Kits. The expansion header on the Starter Kits follows a standard which ensures that commonly
used peripherals such as an SPI, a UART, and an I2C bus, are available on fixed locations on the connector. Additionally, the VMCU,
3V3 and 5V power rails are also available on the expansion header. For detailed information regarding the pinout to the expansion
header on a specific Starter Kit, consult the accompanying user’s guide.

The figure below shows how the WGM110 Wi-Fi Module is connected to the connector and the peripheral functions that are available.

Figure 4.1. Wireless Expansion Board Connector Layout

left hand side of the Wireless Expansion Board, an angled female 20-pin expansion header is provided to allow connection to

Figure 4.2. Expansion Header

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4.1.1 Pass-through Expansion Header

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wireless EXP Board

The Wireless

Expansion Board features a footprint for a secondary expansion header. The signals from the expansion header are di-

rectly tied to the corresponding pins in the footprint, allowing daisy-chaining of additional expansion boards if a connector is soldered in.

4.1.2 Expansion Header Pinout

The table below shows the pin assignments of the Expansion Header, and the port pins and peripheral functions that are available on
the WGM110 Wi-Fi Module.

Table 4.1. Expansion Header Pinout

Expansion Header WGM110 Wi-Fi Module Raspberry Pi Con. Mini Simplicity Con.

Pin Function Pin Peripheral Pin(s) Pin

2 WGM110 Wi-Fi Module voltage

VMCU - 1
domain (power switch set to Low
Power)

4 SPI_MOSI PD0 USART1_MOSI 19, 33 -

6 SPI_MISO PD1 USART1_MISO 21 -

8 SPI_SCLK PD2 USART1_CLK 23, 38 -

10 SPI_CS PD3 USART1_CS 24 -

12 UART_TX PE11 USART0_RX 8 4

14 UART_RX PE10 USART0_TX 10 5

16 I2C_SDA PE0 I2C1_SDA 3 -

18 Board 5V supply. Used to supply

20

LDO regulator

Board 3V3 supply. Only used for

.

5V 2, 4 -

3V3 1, 17 ­board identification.

1 Ground GND 6, 9, 14, 20, 25, 30, 34,392

3 UART_CTS PE13 USART0_RTS 11, 40 -

5 UART_RTS PE12 USART0_CTS 37, 36 -

7 Reset RESETn 16 3

9 GPIO PE14 15 -

11 GPIO PA2 7 -

13 Not Connected - -

15 I2C_SCL PE1 I2C1_SCL 5 -

17 Identification of expansion boards. BOARD_ID_SC

- -

L

19 Identification of expansion boards. BOARD_ID_SD

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- -

A

4.2 Raspberry Pi Connector

Reserved (Board Identification)

WGM1

10 Wi-Fi Module I/O Pin

GND

PE12

PC14

PD0

PC1

PB12

RPI_ID_SD

GND

SPI_SCLK / PD2

SPI_MISO / PD1

PE13

PD2

PE12 / UART_CTS

GND

PC15

GND

RPI_ID_SC

PC0

PA6
PD3 / SPI_CS

SPI_MOSI / PD0

3V3

PE14

PB11

UART_RTS / PE13

GND

PA2

I2C_SCL / PE1

I2C_SDA / PE0

3V3

GND

PE15

RESETn

GND

PC13

PE10 / UART_TX

PE11 / UART_RX

GND

5V
5V

4039

37

33
35

31

38

36

32

34

29

28

27

30

2625

24

23

21 22

2019

17

13
15

1

1

18

16

12
14

9

8

7

10

65

4

3

1 2

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wireless EXP Board

On the

bottom side of the Wireless Expansion Board, a dual row, female socket, 0.1" pitch connector can be soldered in to allow the

WGM110 Wi-Fi Expansion Kit to act as a Raspberry Pi Hardware Attached on Top (HAT) board.

The figure below shows how the WGM110 Wi-Fi Module is connected to the connector and the peripheral functions that are available.

Figure 4.3. Raspberry Pi Connector

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4.2.1 Raspberry Pi Connector Pinout

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wireless EXP Board

The table

below shows the pin assignments of the Raspberry Pi connector, and the port pins and peripheral functions that are available

on the WGM110 Wi-Fi Module.

Table 4.2. Raspberry Pi Connector Pinout

Raspberry Pi Connector Expansion Header Mini Simplicity

Con.

Pin(s) WGM110 Pin Function Raspberry Pi Pin Pin Pin

1 3V3 Board 3V3 supply 3v3 Power 20 -

2 5V Board 5V supply 5v Power 18 -

3 PE0 I2C_SDA BCM 2 (SDA) 16 -

4 5V Board 5V supply 5v Power 18 -

5 PE1 I2C_SCL BCM 3 (SCL) 15 -

6 GND Ground Ground 1 2

7 PA2 GPIO BCM 4 (GPCLK0) 11 -

8 PE11 UART_RX BCM 14 (TXD) 12 4

9 GND Ground GND 1 2

10 PE10 UART_TX BCM 15 (RXD) 14 5

11 (40) PE13 UART_RTS BCM 17 3 -

12 PC13 GPIO BCM 18 (PWM0) - -

13 PB11 GPIO BCM 27 - -

14 GND Ground Ground 1 2

15 PE14 GPIO BCM 22 9 -

16 RESETn Reset BCM 23 7 3

17 3V3 Board 3V3 supply 3v3 Power 20 -

18 PE15 GPIO BCM 24 - -

19 (33) PD0 SPI_MOSI BCM 10 (MOSI) 4 -

20 GND Ground Ground 1 2

21 PD1 SPI_MISO BCM 9 (MISO) 6 -

22 PA6 GPIO BCM 25 - -

23 (38) PD2 SPI_SCLK BCM 11 (SCLK) 8 -

24 PD3 SPI_CS BCM 8 (CE0) 10 -

25 GND Ground Ground 1 2

26 PC0 GPIO BCM 7 (CE1) - -

27 ID_SD ID EEPROM BCM 0 (ID_SD) - -

28 ID_SC ID EEPROM BCM 1 (ID_SC) - -

29 PB12 GPIO BCM 5 - -

30 GND Ground Ground 1 2

31 PC1 GPIO BCM 6 - -

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VMCU

1
3

RST

5

VCOM_TX

9

Not Connected (NC)

7

SWDIO

2

GND

4

VCOM_RX

6

SWO

8

SWCLK

10

Not Connected (NC)

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wireless EXP Board

Raspberry Pi Connector Expansion Header Mini Simplicity

Con.

Pin(s) WGM110 Pin Function Raspberry Pi Pin Pin Pin

32 PC15 GPIO BCM 12 (PWM0) - -

33 (19) PD0 GPIO BCM 13 (PWM1) 4 -

34 GND Ground Ground 1 2

35 PC14 GPIO BCM 19 (MISO) - -

36 (37) PE12 UART_CTS BCM 16 5 -

37 (36) PE12 GPIO BCM 26 5 -

38 (23) PD2 GPIO BCM 20 (MOSI) 8 -

39 GND Ground Ground 1 2

40 (11) PE13 GPIO BCM 21 (SCLK) 3 -

Note: Several of

the Raspberry Pi GPIO pins are connected together when the WGM110 Wi-Fi Module Radio Board is inserted. This is
because of connections on the radio board itself, and are not because they are connected together on the Wireless EXP Board. Care
must be taken when driving these pins to avoid creating short circuits.

4.3 Mini Simplicity Connector

The Mini Simplicity connector, featured on the WGM110 Wi-Fi Expansion Kit, allows the use of an external debugger, such as those
featured on one of the kits listed under Section 1. Introduction. In addition to providing serial wire debug (SWD) and virtual COM port
functionality, the debugger on the STKs can also support advanced energy profiling tools. For more information see AN958: Debugging

and Programming Interfaces for Custom Designs.

Note: Using the Mini Simplicity connector with the kit requires a Silicon Labs debug adapter kit (OPN: SLSDA001A).

The pinout of the connector, as seen from the WGM110 Wi-Fi Module side, is illustrated in the figure below.

Figure 4.4. Mini Simplicity Connector

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UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wireless EXP Board

4.3.1 Mini Simplicity Connector Pinout

The pin assignment of the Mini Simplicity connector on the board is given in the table below.

able 4.3. Mini Simplicity Connector Pin Descriptions

T

Pin Number WGM110 Connection Function Description

1 VMCU VAEM Target voltage on the debugged application. Supplied and monitored

by the AEM when the power selection switch on the STK used for de-

bugging is in the "AEM" position.

2 GND GND Ground

3 Reset DBG_RST Reset

4 PE11 VCOM_RX Virtual COM Rx

5 PE10 VCOM_TX Virtual COM Tx

6 PF2 DBG_SWO Serial Wire Output

7 PF1 DBG_SWDIO Serial Wire Data

8 PF0 DBG_SWCLK Serial Wire Clock

9 NC Not connected -

10 NC Not connected -

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Expansion

Header

Raspberry

Pi

Connector

Mini Simplicity

Connector

Power

Switch

Low
Power
(AEM)

High
Power
(LDO)

VMCU

LDO

IN

OUT

3.3 V

5V

3V3

WGM110

Wi-Fi Module

5V

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wireless EXP Board

4.4 Power Supply

There are three ways to provide power to the kit:

• The kit can be connected to, and powered by

• The kit can be connected to, and powered by, a Raspberry Pi

• If the kit is connected to a Silicon Labs MCU STK, the kit can also be powered through the Mini Simplicity Connector.

Note: Connecting the WGM110 Wi-Fi Expansion Kit to both an STK and a Raspberry Pi at the same time is not a valid option.

When connected to a Silicon Labs MCU STK, the WGM110 Wi-Fi Module can either be powered by the VMCU rail present on the Ex­pansion Header, or through an LDO regulator on board the Wireless Expansion Board. The LDO regulator draws power from the 5V
net, and hence, the power consumption of the WGM110 Wi-Fi Module will not be included in any AEM measurements performed by the
MCU STK. A mechanical power switch on the Wireless Expansion Board is used to select between Low Power (AEM) mode and High
Power (LDO) mode. When the switch is set to Low Power (AEM) mode, the WGM110 Wi-Fi Module is connected to the VMCU net on
the Expansion Header. When the switch is set to High Power (LDO) mode, the WGM110 Wi-Fi Module is connected to the output of the
LDO. For applications requiring high power consumption, or when the WGM110 Wi-Fi Expansion Kit is connected to a Raspberry Pi,
the power switch must be set to High Power (LDO) mode.

The power topology is illustrated in the figure below.

, a Silicon Labs MCU STK

Figure 4.5. WGM110 Wi-Fi Expansion Kit Power Topology

The power supply options are summarized in Table 4.4 WGM110 Wi-Fi Expansion Kit Power Options on page 15. Information on
placement of the power switch and the connectors can be found in Section 2.1 Hardware Layout.

Table 4.4. WGM110 Wi-Fi Expansion Kit Power Options

Host Host MCU

STK Power

Switch

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MCU STK AEM BAT Low power (AEM) MCU STK provides power to

MCU STK AEM BAT High power (LDO) MCU is powered by MCU

MCU STK BA

T AEM Low power (AEM) External STK debugger pro-

Debugger (STK) Power

Switch

Wireless Expansion Board

Power Switch

Power Source

both MCU and radio board.

STK. Radio board is pow­ered by LDO on the Wire-

less Expansion Board

vides power to both MCU

and radio board.

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Wireless EXP Board

Host Host MCU

STK Power

Debugger (STK) Power

Switch

Wireless Expansion Board

Power Switch

Power Source

Switch

Raspberry Pi - BAT High power (LDO) Radio board is powered by

LDO on the Wireless Expan-

sion Board

Note: It is important to only use the configurations provided in the table above in order to avoid any power conflicts. Furthermore, it is
important to make sure that the coin cell battery holder is empty whenever the power switch should be set to BAT

.

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UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Reconfiguring the Wi-Fi Module Firmware

5. Reconfiguring the Wi-Fi Module Firmware

The WGM110 Wi-Fi Module has several hardware interfaces that can be enabled, including the SPI slave interface, the USB device,
and the micro-SD card. To configure the module's hardware interfaces, the module firmware needs to be recompiled and re-program­med.

The Mini Simplicity connector on the Wireless EXP Board provides a Serial Wire Debug interface to the WGM110 module, which can be
used to upload the reconfigured module firmware. Alternatively, the Device Firmware Update protocol (DFU) can be used to update the
firmware over the UART or SPI interface.

5.1 Building the Module Firmware

Configuring the hardware interface settings of the WGM110 can be done using either the BGBuild command line tool, or the GUI based
BGTool. UG161: WGM110 Wi-Fi Module Configuration Guide explains in detail how to configure the hardware interfaces of the
WGM110 Wi-Fi Module.

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5.2 Programming the Module Firmware

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Reconfiguring the Wi-Fi Module Firmware

The 10-pin

Mini Simplicity connector on the Wireless EXP Board provides a Serial Wire Debug connection to the WGM110 Wi-Fi Mod­ule that can be used to upload the re-configured module firmware. Silicon Labs offers a Simplicity Debug Adapter Board that connects
between the two 20-pin debug connectors on Silicon Labs Starter Kits and the 10-pin connector on the Wireless EXP Board.

Figure 5.1. MCU Starter Kit as Programmer for WGM110 Wi-Fi Module Radio Board

When programming the module firmware using the BGTool, the Starter Kit's debug multiplexer must be set to "Debug OUT". This allows

to program the module connected through the debug adapter instead of the on-board MCU. The Simplicity Studio tool provides a

the kit
device configuration utility that can change the kit's debug mode between "MCU" and "OUT".

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Figure 5.2. Configuring the Debug Mode

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Reconfiguring the Wi-Fi Module Firmware

Remember to change the debug mode back to MCU after the module has been configured in order to continue application development
on the host MCU.

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UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Schematics, Assembly Drawings, and BOM

6. Schematics, Assembly Drawings, and BOM

Schematics, assembly drawings, and bill of materials (BOM) are available through Simplicity Studio when the kit documentation pack­age has been installed.

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SLEXP4320A

WGM110 WiFi Expansion Kit

124802042

17-06-26

A00

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

7. Kit Revision History

The kit revision can be found printed on the kit packaging label, as outlined in the figure below.

Figure 7.1. Kit Label

7.1 SLEXP4320A Revision History

Kit Revision Released Description

Kit Revision History

A00 2017-06-26 Initial release.

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8. Document Revision History

Revision 1.0

2017-06-12

• Initial document revision.

UG291: WGM110 Wi-Fi® Expansion Kit User's Guide

Document Revision History

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intending to use the Silicon Labs products. Characterization data, available modules and peripherals, memory sizes and memory addresses refer to each specific device, and "Typical"
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