Laird WB45NBT Reference Manual

A

Reference Guide

WB45NBT

Version 1.10

WB45NBT

Reference Guide

Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com

www.lairdtech.com/wi-fi

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© Copyright 2017 Laird. All Rights Reserved

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REVISION HISTORY

Version

Date

Notes

Approver

1.0

20 August 2013

Initial Version

Andrew Chen

1.1

22 August 2013

Minor revisions and formatting edits

Andrew Chen

1.2

28 July 2014

Minor edits for Rev 2 board

Andrew Chen

1.3

6 July 2015

Added Note regarding No Serial Output

Andrew Chen

1.4

6 August 2015

Added BT/BLE

Andrew Chen

1.5

27 April 2016

Removed references to connecting to an open AP by
default in the Automatic Remote Update section.

Mark Calhoun

1.6

07 July 2016

Changed bootstrap.bin references to at91bs.bin
Updated to new template

Doug Smith

1.7

10 April 2017

Added WB Security section

Andrew Dobbing

1.8

1 May 2017

OS Support. Removed SAM-BA section and directed to
app note at lairdtech.com

Jay White

1.9

7 June 2017

Updates to clarify lack of USB to Wi-Fi layer 2 bridging
support

Dan Kephart

1.10

17 Nov 2017

Updated DCAS authentication information

Andrew Dobbing

WB45NBT

Reference Guide

Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com

www.lairdtech.com/wi-fi

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© Copyright 2017 Laird. All Rights Reserved

Americas: [phone]

Europe: [phone]

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CONTENTS

1 Introduction to the Laird WB45NBT Device ...................................................................................................... 4

2 Product Description ........................................................................................................................................... 4

3 Software ............................................................................................................................................................ 4

3.1 WB45NBT Usage ........................................................................................................................................ 5

4 Configuring IP Based Connectivity ..................................................................................................................... 5

4.1 Choosing an Interface to the WB .............................................................................................................. 5

4.2 Configuring the WB to Use Layer 2 Bridging or Layer 3 NAT ..................................................................... 6

4.3 Choosing Layer 2 Bridge or Layer 3 NAT – Use Cases ................................................................................ 6

4.4 WB Configurations – Use Case Examples .................................................................................................. 8

4.5 Activating the New WB Configuration ..................................................................................................... 12

5 Set Up – USB Ethernet on a Host PC................................................................................................................ 12

6 Setting Up a PPP Link Over RS232 ................................................................................................................... 13

7 Building the WB from Source .......................................................................................................................... 13

8 Updating the WB50NBT Software ................................................................................................................... 14

8.1 Flash Programming Using fw_update ..................................................................................................... 14

8.2 Troubleshooting U-Boot .......................................................................................................................... 18

8.3 Flash Programming Using the Atmel SAM-BA Utility .............................................................................. 19

9 Debugging ........................................................................................................................................................ 19

9.1 Application Debugging ............................................................................................................................ 19

9.2 Connecting a Device or File to a Socket .................................................................................................. 19

9.3 Setting Up Stand-alone FTP, TFTP, and SSH servers ................................................................................ 20

10 Breakout Board Schematic and BOM .......................................................................................................... 20

11 Developing and Integrating Using the Development Kit ............................................................................. 20

11.1 Software Tools and Techniques ............................................................................................................... 20

11.2 Finding Version Information .................................................................................................................... 21

12 Hardware Use Notes .................................................................................................................................... 21

12.1 GPIOs ....................................................................................................................................................... 21

12.2 Analog to Digital Converter ..................................................................................................................... 23

13 WB Security ................................................................................................................................................. 24

13.1 Solutions to Enhance Security ................................................................................................................. 24

13.2 Best Practices for Improving Wireless Network Security ........................................................................ 25

13.3 WB inetd and WB init-scripts .................................................................................................................. 25

WB inetd .......................................................................................................................................................... 25

WB init-scripts ................................................................................................................................................. 26

14 References ................................................................................................................................................... 28

15 More Information and Support ................................................................................................................... 28

WB45NBT

Reference Guide

Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com

www.lairdtech.com/wi-fi

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© Copyright 2017 Laird. All Rights Reserved

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Europe: [phone]

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1 INTRODUCTION TO THE LAIRD WB45NBT DEVICE

The Laird WB45NBT wireless bridge module is a wireless communications subsystem that may be integrated into
a variety of host devices via a number of available electronic and logical interfaces.

Interfaces

Features

Specifications

▪ Fast Ethernet
▪ Serial UART
▪ USB
▪ SPI
▪ I2C
▪ 80 pin board with mating

options

▪ Mounting holes

▪ ARM9 processor (396 MHz)
▪ 64 MB of LPDDR (Lower Power

DDR) memory

▪ 128 MB of NAND flash storage

▪ Length: 40 mm
▪ Width: 40 mm
▪ Height: 3.8 mm

2 PRODUCT DESCRIPTION

The Laird WB45NBT provides complete enterprise-class Wi-Fi connectivity with
an integrated TCP/IP stack, full support for IEEE 802.11a/b/g/n and Bluetooth 4.0
dual-mode air standards, and a fully integrated security supplicant providing

802.11i/WPA2 Enterprise authentication, data encryption, and BT protocol
stacks.

The WB45NBT is a fully integrated module with RF shielding and two U.FL type
antenna connectors. The Main antenna (for Wi-Fi) and the Auxiliary antenna (for
Bluetooth) work separately to get the best coexistence performance. Although
not currently supported, the third antenna connector multiplexes both the Wi-Fi
and Bluetooth signals into a single RF port through the use of a T/R switch.

Note: For additional information on the hardware aspects of the WB45NBT, please refer to the Hardware

Integration Guide download on the WB45NBT Product Page.

3 SOFTWARE

The WB45NBT has 128 MB of NAND flash memory that is divided into partitions (see Table 1). It uses 4-bit ECC in
a 64 bit OOB area in each sector.

Table 1: Flash memory partitions

Image

Partition

Start

End

Size

MTD

Type

at91bs.bin

at91bs

0x00000000

0x0001FFFF

128 KB

/dev/mtd0

Raw binary

u-boot.bin

u-boot

0x00020000

0x0009FFFF

512 KB

/dev/mtd1

Raw binary

-

u-boot-env

0x000A0000

0x000BFFFF

128 KB

/dev/mtd2

U-boot env

-

redund-env

0x000C0000

0x000DFFFF

128 KB

/dev/mtd3

U-boot backup env

kernel.bin

kernel-a

0x000E0000

0x0035FFFF

2.5 MB

/dev/mtd4

Kernel image

kernel.bin

kernel-b

0x00360000

0x005DFFFF

2.5 MB

/dev/mtd5

Kernel image

rootfs.ubi

rootfs-a

0x005E0000

0x02BDFFFF

38 MB

/dev/mtd6

UBI

rootfs.ubi

rootfs-b

0x02BE0000

0x051DFFFF

38 MB

/dev/mtd7

UBI

WB45NBT

Reference Guide

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http://ews-support.lairdtech.com

www.lairdtech.com/wi-fi

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N/A

user

0x051E0000

0x07EFFFFF

46 MB

/dev/mtd8

Raw

N/A

logs

0x07F00000

0x07F7FFFF

512 KB

/dev/mtd9

Raw

There are four basic types of binary images that can be programmed into the flash memory:

▪ Bootstrap loader
▪ U-boot boot loader
▪ Linux kernel
▪ Root filesystem

The flash partition layout allows for two kernel images (kernel-a and kernel-b), as well as two file system images
(rootfs-a and rootfs-b). This allows an update to an alternate image without disturbing the currently running
system. Additionally, if something goes awry with the newly updated image, the original image is still available.
The update program is intelligent enough to program the correct partition (the one which is not currently being
run).

The filesystem is stored using a format called Unsorted Block Images (UBI). This is a filesystem that lies on top of
the Memory Technology Device (MTD) layer. The MTD layer handles bad block mapping. When a bad block is
encountered, it is simply skipped and not used. As new bad blocks occur, they are marked as such and handled
properly between the MTD and UBI file system. The UBIFS handles wear-leveling.

3.1 WB45NBT Usage

One of the main applications of the WB is to enable Wi-Fi on your host device using one of the available
interfaces of the WB module. This section describes how to do this from a Linux environment.

The quickest way to start controlling the WB is through the built-in Linux command line interface (CLI). The WB's
CLI can be accessed via the DEBUG UART (settings: 115200 8N1) or via Secure Shell (ssh). ssh logins can be
accepted on Ethernet (IP address assigned via DHCP – see your local DHCP server for address) or via USB
Ethernet at IP address 192.168.3.1 port 22.

Once CLI access is available, configuration files on the device can be examined or modified.

4 CONFIGURING IP BASED CONNECTIVITY

This section covers enabling your host device to communicate over Wi-Fi via the WB. The predominant use cases
involve using the WB as Ethernet to Wi-Fi, USB to Wi-Fi, or Serial PPP (RS232) to Wi-Fi peripherals. These use

cases allow normal IP network connectivity via the WB’s Wi-Fi interface. We’ll explain these use cases in this
guide, but they aren’t the only ones available; more complex configurations are also possible. Please contact

Laird support if you have a use case this is not covered in this document.

4.1 Choosing an Interface to the WB

The first consideration in configuring the Wi-Fi connectivity is what interface will be used between the host
device and the WB. The most common three options are Ethernet, USB Ethernet, and Serial (RS232). Each of
these cases has the host device sending and receiving IP packets and the WB forwarding packets to and from the
Wi-Fi interface once connected.

▪ Ethernet – Refers to the standard 802.3 Ethernet.
▪ USB connectivity – We recommend setting up the WB to enable USB CDC Ethernet (also known as USB

Gadget Ethernet). Then installing the proper drivers on the host device. This allows the WB to appear as a
standard Ethernet network device.

WB45NBT

Reference Guide

Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com

www.lairdtech.com/wi-fi

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Europe: [phone]

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▪ Serial (RS232) – We recommend setting up PPP over serial on the WB and the host device and enabling IP

over PPP. Optionally, the host device can send raw byte data to a UART on the WB and the WB can
forward that data bi-directionally to a TCP socket via the built in socat program.

4.2 Configuring the WB to Use Layer 2 Bridging or Layer 3 NAT

The second consideration in configuring Wi-Fi connectivity is whether to configure the WB to act as a Layer 2
Bridge or a Layer NAT device.

4.2.1 Layer 2 Bridge

When configured as a Layer 2 bridge, the WB acts as a transparent bridge for Layer 2 packets carrying an IP­based packet from the host device. The WB expects the host to do all Layer 3 IP configuration such as static
addressing or DHCP for the Wi-Fi network. This mode applies to Ethernet to Wi-Fi. In the Layer 2 Bridge
configuration, it appears to the host device that it is connected to a physical network.

4.2.2 Layer 3 NAT

When configured to do Layer 3 NAT, the WB is configured to run a DHCP client or have a static IP address on the
WB’s Wi-Fi interface. In this configuration, a static non-routable IP address is assigned on the host device’s
communication interface and the corresponding interface on the WB. Port NAT and IP masquerading would then
enable seamless communication from the host interface to the Wi-Fi network. This mode applies to Ethernet to
Wi-Fi, USB Ethernet to Wi-Fi, and Serial PPP to Wi-Fi. Seven common use cases are detailed that describe the WB
configured as a bridge or NAT device.

Note: Please contact Laird support if you have a use case not covered here in this document.

4.3 Choosing Layer 2 Bridge or Layer 3 NAT – Use Cases

4.3.1 Use Case 1

A single host device with a DHCP client for Wi-Fi on the host device’s Ethernet to the WB.

This is often used when the WB if functioning as an Ethernet to Wi-Fi dongle on an existing product where the
Ethernet is set up to use DHCP.

▪ Solution: Bridging

The WB acts as a transparent bridge between the Ethernet and Wi-Fi.

▪ Caveats:

It should send a ping packet or other IP packet from the host device’s interface to the WB once a new IP

address has been assigned to register the host device with the WB’s bridge code. Otherwise, the bridge

may not forward incoming Wi-Fi packets to the host device.

In addition, this configuration is not able to renew DHCP on a roam without software using SDK Events to
alert the host device to trigger DHCP on a roam. This is only an issue for networks configured with multiple
subnets on the same SSID (determine if your customers do this).

See Single Host Device with DHCP running on the WB for NAT Configuration to solve this issue.

Use Case 1 Example

WB45NBT

Reference Guide

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http://ews-support.lairdtech.com

www.lairdtech.com/wi-fi

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4.3.2 Use Case 2

A single host device with a static IP for Wi-Fi on the host device’s Ethernet to the WB

The IP address that is used on the Wi-Fi network is statically assigned by the host device. This is often the case
when using the WB as an Ethernet to Wi-Fi dongle on an existing product where the Ethernet was set up to use
static IP addresses.

▪ Solution: Bridging

The WB acts as a transparent bridge between the Ethernet and Wi-Fi.

▪ Caveats:

It should send a ping packet or other IP packet from the host device’s interface to the WB using static IP
address to register host device with WB’s bridge code. Otherwise the bridge may not forward incoming
Wi-Fi packets to the host device.

Use Case 2 Example

4.3.3 Use Case 3

A single host device with DHCP running on the WB’s Wi-Fi interface

A single device is connected to the Ethernet, USB Ethernet, or PPP serial; a DHCP client is running on the WB to
handle the Wi-Fi DHCP assignment.

▪ Solution: NAT

The WB does IP NAT and port masquerading to forward traffic from the Wi-Fi to host device. Host device
interface to the WB along with the corresponding WB interface should be assigned a non-routable

169.254.x.x IP address. The WB does a DHCP request on roam to support networks configured with
multiple subnets on the same SSID (determine if your customers do this).

Use Case 3 Example

4.3.4 Use Case 4

A single host device with a static IP on the WB’s Wi-Fi interface

▪ Solution: NAT

The WB does IP NAT and port masquerading to forward traffic from Wi-Fi to the host device. The host
device interfaces to the WB, along with the corresponding WB interface, should be assigned a non­routable 169.254.x.x IP address.

Use Case 4 Example

4.3.5 Use Case 5

Multiple host devices connected via Ethernet with DHCP running on the WB’s Wi-Fi interface

▪ Solution: NAT

The WB does IP NAT and port masquerading to forward traffic from the Wi-Fi to each host device. Host
device interfaces to the WB along with the corresponding WB interface should be assigned non-routable

169.254.x.x IP addresses. The WB does a DHCP request on roam to support networks configured with
multiple subnets on the same SSID (determine if your customers do this).

Use Case 5 Example

WB45NBT

Reference Guide

Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com

www.lairdtech.com/wi-fi

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4.3.6 Use Case 6

Multiple host devices connected via Ethernet with a static IP on the WB’s Wi-Fi interface

▪ Solution: NAT

The WB does IP NAT and port masquerading to forward traffic from Wi-Fi to each host device. Host device
interfaces to the WB, along with the corresponding WB interface, should be assigned non-routable

169.254.x.x IP addresses. The WB does a DHCP request on roam to support networks configured with
multiple subnets on the same SSID (determine if your customers do this).

Use Case 6 Example

4.3.7 Use Case 7

Multiple host devices connected via Ethernet with DHCP running or a static IP on each host device interface
to the WB

▪ Solution: Use NAT instead

We recommend that you use a NAT-based configuration instead. The WB does not currently support this
use case in the standard release. If this use case is required, please contact Laird with complete details of
the use case for potential customized options.

Use Case 7 Example

4.4 WB Configurations – Use Case Examples

Each example configuration uses a combination of the sdc_cli command line utility, the ifrc command line utility,
and editing the /etc/network/interfaces file. These can be done once console access has been established with
the WB as described in the WB45NBT Quick Start Guide (available from the Documentation tab of the Laird

WB45NBT product page). These configurations are only examples for the WB’s configuration. Example host test

device configurations are described in the following section to complete early testing.

Note: Editing of the /etc/network/interfaces file should be done with vi. To learn how to use vi as an

editor, there are many online tutorials.

To begin editing, execute the following:

# vi /etc/network/interfaces

Note: The following examples describe how to enable Ethernet to Wi-Fi connectivity. In these cases, the

Ethernet interface is referred to as eth0. To enable USB Ethernet to Wi-Fi, substitute eth0 with
usb0 and for PPP Serial to Wi-Fi substitute eth0 with ppp0. The Wi-Fi interface is wlan0 in the
examples.

4.4.1 Use Case 1 Example

A single host device with a DHCP client for Wi-Fi on the host device’s Ethernet to the WB.

Enable the Ethernet interface and make sure it doesn’t use an IP configuration:

# sdc_cli iface set auto eth0 on

# sdc_cli iface set method eth0 manual

WB45NBT

Reference Guide

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http://ews-support.lairdtech.com

www.lairdtech.com/wi-fi

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Enable the Wi-Fi interface and make sure it doesn’t use an IP configuration:

# sdc_cli iface set auto wlan0 on
# sdc_cli iface set method wlan0 manual

Enable bridging between Ethernet and Wi-Fi:

# sdc_cli iface set auto br0 on
# sdc_cli iface set method br0 manual
# sdc_cli iface set bridge_ports br0 eth0 wlan0

Optional: If IP communication between the WB and host device for configuration or otherwise is desired, then

additional IP configuration should be enabled on the bridge interface (br0):

# sdc_cli iface set method br0 static
# sdc_cli iface set address br0 169.254.0.1
# sdc_cli iface set netmask br0 255.255.255.0
# sdc_cli iface set broadcast br0 169.254.0.255

4.4.2 Use Case 2 Example

A single host device with a static IP for Wi-Fi on the host device’s Ethernet to the WB

Enable the Ethernet interface and make sure it doesn’t use an IP configuration:

# sdc_cli iface set auto eth0 on
# sdc_cli iface set method eth0 manual

Enable the Wi-Fi interface and make sure it doesn’t use an IP configuration:

# sdc_cli iface set auto wlan0 on
# sdc_cli iface set method wlan0 manual

Enable bridging between Ethernet and Wi-Fi:

# sdc_cli iface set auto br0 on
# sdc_cli iface set method br0 manual
# sdc_cli iface set bridge_ports br0 eth0 wlan0

Optional: If IP communication between the WB and host device for configuration or otherwise is desired, then

additional IP configuration should be enabled on the bridge interface (br0):

# sdc_cli iface set method br0 static
# sdc_cli iface set address br0 169.254.0.1
# sdc_cli iface set netmask br0 255.255.255.0
# sdc_cli iface set broadcast br0 169.254.0.255

4.4.3 Use Case 3 Example

A single host device with DHCP running on the WB’s Wi-Fi interface