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Bluetooth LE for Wi-Fi Onboarding: A Game-Changer for IoT Connectivity

Wi-Fi has become a cornerstone of modern connectivity, powering everything from laptops and smartphones to smart home devices and industrial IoT systems.

Bluetooth LE for Wi-Fi Onboarding A Game-Changer for IoT Connectivity

Sponsored by Nordic Semiconductor

Wi-Fi has become a cornerstone of modern connectivity, powering everything from laptops and smartphones to smart home devices and industrial IoT systems. However, while Wi-Fi excels in delivering reliable, high-speed data transfer, Wi-Fi onboarding—especially for IoT devices—remains a significant challenge.

What is Wi-Fi?

Wi-Fi is one of the most widely used wireless technologies, enabling devices to connect to the internet or local networks without physical cables.

Based on IEEE 802.11 standards, Wi-Fi operates in various frequency bands (2.4 GHz, 5 GHz, and, more recently, 6 GHz with Wi-Fi 6E). It powers everything from smartphones and laptops to smart home devices and industrial IoT solutions.

While Wi-Fi is known for providing high-speed data connectivity, its role extends beyond web browsing and video streaming. In the IoT landscape, Wi-Fi is a critical backbone for devices requiring constant or periodic internet access while balancing power consumption and efficiency.

However, traditional Wi-Fi onboarding—connecting a device to a network—can be a pain point, especially for constrained IoT devices. This challenge becomes particularly evident in IoT deployments where devices may need to be provisioned at scale, in environments with limited access, or by users with varying technical expertise.

Traditional Wi-Fi onboarding methods often involve complex processes that can lead to setup failures, user frustration, and increased support costs. These limitations have driven the industry to seek more efficient and user-friendly alternatives for connecting IoT devices to Wi-Fi networks. Enter Bluetooth Low Energy (LE): a technology that offers a seamless, user-friendly solution for Wi-Fi onboarding.

In this post, we will:

The Role of Wi-Fi in IoT and Low-Power Connectivity

Wi-Fi is a go-to solution for many IoT applications, but its role in low-power, constrained devices differs greatly from its use in traditional computing. Unlike smartphones and laptops, which prioritize high throughput and low latency, IoT devices have unique connectivity requirements:

Wi-Fi 6 and Its Role in IoT

Wi-Fi 6 (802.11ax) introduces several key enhancements that make it more suitable for IoT applications, addressing issues like congestion, power efficiency, and scalability.

Features of Wi-Fi 6 Unique to IoT Applications

1. Orthogonal Frequency-Division Multiple Access (OFDMA)

2. Basic Service Set (BSS) Coloring & Beamforming

3. Target Wake Time (TWT)

With these enhancements, Wi-Fi 6 is better suited for IoT deployments than its predecessors, but connectivity challenges still exist—especially when it comes to onboarding. This is where Bluetooth Low Energy (LE) plays a crucial role.

Nordic’s Wi-Fi Solution and the nRF70 Series

Nordic Semiconductor, known for its leadership in Bluetooth Low Energy (LE), has expanded into Wi-Fi with the nRF70 series—a low-power Wi-Fi 6 companion IC designed specifically for IoT applications.

Unlike traditional Wi-Fi chipsets optimized for high throughput, the nRF70 series focuses on power efficiency, coexistence with Bluetooth LE, and secure, scalable connectivity.

Key Features of the nRF70 Series for IoT

With Nordic’s nRF70 Wi-Fi companion IC, developers can create low-power, dual-radio IoT solutions that leverage Bluetooth LE for seamless onboarding and control while using Wi-Fi for higher-bandwidth data exchange when needed.

Nordic's Wi-Fi Solution Options

Nordic has a few solutions available for Wi-Fi connectivity based on the nRF70 Series. The series is designed to operate alongside Nordic’s existing nRF52 and nRF53 Series Bluetooth LE and nRF91 Series cellular IoT devices. In addition, the nRF70 Series can also be used with non-Nordic host devices.

The portfolio consists of:

Source: Nordic DevAcademy Wi-Fi Fundamentals Course

nRF7002

The nRF7002 is the first device in our portfolio of unique Wi-Fi products, and it provides all the features of the nRF70 Series.

nRF7001

With its single-band 2.4 GHz radio, the nRF7001 IC is intended for customers who don’t need dual-band functionality.

It has all the same main features as the nRF7002 IC.

nRF7000

The nRF7000 IC is designed explicitly for SSID-based Wi-Fi locationing. It enables active and passive scanning of Wi-Fi networks to acquire the SSIDs of nearby APs for locationing purposes.

Nordic's Wi-Fi Development Hardware

Nordic also offers a few boards for Wi-Fi development:

nRF7002 Development Kit

nRF7002 DK

The nRF7002 DK combines the Wi-Fi 6 capabilities of the nRF7002 companion IC with the multi-protocol capabilities of the nRF5340 System on Chip (SoC), like Bluetooth LE, Bluetooth mesh, NFC, Matter, Thread, Zigbee, etc. The DK provides everything needed to start developing low-power Wi-Fi applications.

nRF7002 Evaluation Kit

nRF7002 EK

The nRF7002 EK comes in the form of an Arduino shield and is designed to complement the nRF52840 DK, nRF5340 DK, and nRF9160 DK.

nRF7002 Evaluation Board

nRF7002 EB
Thingy:53 with nRF7002 EB

The nRF7002 EB is a plug-in board intended to add Wi-Fi 6 connectivity to the Nordic Thingy:53.

Wi-Fi Onboarding: The Challenge

Before an IoT device can communicate over Wi-Fi, it must be connected to a network—a process known as Wi-Fi provisioning or onboarding. This involves:

  1. Scanning for available networks
  2. Selecting the correct Wi-Fi network
  3. Entering credentials (SSID & password)
  4. Authenticating and connecting to the network

For traditional consumer devices like laptops and smartphones, this is straightforward.

But for IoT devices—which often lack a screen, keyboard, or even user input options—Wi-Fi provisioning can be a frustrating experience.

Problems with Traditional Wi-Fi Onboarding

No Universal Standard for Onboarding

The “Wi-Fi Network Shuffle”

Inconsistent User Experience Across Devices

Lack of Feedback During the Process

For industrial and commercial applications, IT-managed networks and enterprise authentication add further complexity, making traditional Wi-Fi onboarding even more challenging or sometimes even impossible!

💡 Solution? Use Bluetooth LE for Wi-Fi onboarding!

Why Use Bluetooth LE for Wi-Fi Onboarding?

There are quite a few reasons to implement the use of Bluetooth LE for Wi-Fi onboarding (instead of the traditional SoftAP method).

Here are some of the most prominent ones:

Seamless User Experience

Reliable Communication

Security & Flexibility

Suitable for More Deployment Scenarios

Wi-Fi Onboarding Sample Application and How It Works (nRF Connect SDK)

Nordic Semiconductor provides a Wi-Fi provisioning sample in the nRF Connect SDK, demonstrating Bluetooth LE-based Wi-Fi onboarding for the nRF70 Series.

In this article, we'll reference this example and demonstrate how it works down to the Bluetooth LE packet level. We'll be using the nRF Connect SDK (v2.9.0).

Here's a simplified step-by-step of the Wi-Fi onboarding process using Bluetooth LE:

The smartphone application that we'll be using is the Nordic Semiconductor nRF Wi-Fi Provisioner app (available for both iOS and Android):

nRF Wi-Fi Provisioner Mobile App (iOS)

As you can see, there are multiple Wi-Fi provisioning modes: over Bluetooth LE, over Wi-Fi, and over NFC.

For our exercise, we'll be using the "Wi-Fi provisioning over Bluetooth LE" mode.

Step #1: We'll start by creating a new project based on the existing example in the SDK:

Creating a project from the Wi-Fi Provisioning using Bluetooth LE example

Step #2: Once we've created the project, we can go ahead and add a Build Configuration for it by choosing nRF7002dk/nrf5340/cpuapp as the Board Target.

Adding a Build Configuration to the project

Step #3: If you left the box labeled "Build after generating configuration" checked, the project will be built automatically after adding the Build Configuration. This process will take a few seconds, but it should build fine with no issues out of the box.

Step #4: Make sure you connect the nRF7002 DK to your computer and that it is recognized in Visual Studio Code within the nRF Connect Extension:

Development Kit connected and detected in nRF Connect Extension in VS Code

[Optional] Step #5: Since the DK and phone will be establishing Bluetooth LE pairing between them, and we want to sniff the communication in the process, we need to know the pairing key (i.e., the LTK).

To do this, we'll enable one configuration that prints out the LTK so we can enter it into the sniffer's software and decrypt the Bluetooth LE communication between the DK and the phone. Add the following (highlighted) line to the prj.conf file in the project:

#
# Copyright (c) 2022 Nordic Semiconductor ASA
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#

CONFIG_BT_LOG_SNIFFER_INFO=y

CONFIG_WIFI=y
CONFIG_WIFI_NRF70=y
CONFIG_NRF70_SR_COEX=y
CONFIG_NRF70_SR_COEX_RF_SWITCH=y

# WPA supplicant
CONFIG_WIFI_NM_WPA_SUPPLICANT=y

# Networking
CONFIG_NETWORKING=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_LOG=y
CONFIG_NET_IPV6=n
CONFIG_NET_IPV4=y
CONFIG_NET_UDP=y
CONFIG_NET_TCP=y
CONFIG_NET_DHCPV4=y
CONFIG_DNS_RESOLVER=y

CONFIG_NET_STATISTICS=y

CONFIG_NET_PKT_RX_COUNT=8
CONFIG_NET_PKT_TX_COUNT=8

# Below section is the primary contributor to SRAM and is currently
# tuned for performance, but this will be revisited in the future.
CONFIG_NET_BUF_RX_COUNT=16
CONFIG_NET_BUF_TX_COUNT=16
CONFIG_HEAP_MEM_POOL_SIZE=183600
CONFIG_NET_TC_TX_COUNT=1

CONFIG_NET_IF_UNICAST_IPV4_ADDR_COUNT=1
CONFIG_NET_MAX_CONTEXTS=5
CONFIG_NET_CONTEXT_SYNC_RECV=y

CONFIG_INIT_STACKS=y

CONFIG_NET_L2_ETHERNET=y

CONFIG_NET_CONFIG_SETTINGS=y
CONFIG_NET_CONFIG_INIT_TIMEOUT=0

CONFIG_NET_CONFIG_MY_IPV4_ADDR="192.165.100.150"
CONFIG_NET_CONFIG_PEER_IPV4_ADDR="192.165.100.1"

CONFIG_NET_SOCKETS_POLL_MAX=10

# Memories
CONFIG_MAIN_STACK_SIZE=5200
CONFIG_NET_TX_STACK_SIZE=4096
CONFIG_NET_RX_STACK_SIZE=4096

# Debugging
CONFIG_STACK_SENTINEL=y
CONFIG_DEBUG_COREDUMP=y
CONFIG_DEBUG_COREDUMP_BACKEND_LOGGING=y
CONFIG_DEBUG_COREDUMP_MEMORY_DUMP_MIN=y

# Kernel options
CONFIG_ENTROPY_GENERATOR=y

# Logging
CONFIG_LOG=y

CONFIG_NET_L2_WIFI_MGMT=y

CONFIG_BT=y
CONFIG_BT_SMP=y
CONFIG_BT_PERIPHERAL=y

CONFIG_BT_BUF_ACL_RX_SIZE=151
CONFIG_BT_L2CAP_TX_MTU=147
CONFIG_BT_BUF_ACL_TX_SIZE=151

CONFIG_BT_RX_STACK_SIZE=5120
CONFIG_BT_BONDABLE=n
CONFIG_BT_DEVICE_NAME_DYNAMIC=y

CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y

CONFIG_NVS=y

CONFIG_SETTINGS=y
CONFIG_SETTINGS_NVS=y

CONFIG_WIFI_CREDENTIALS=y
CONFIG_WIFI_CREDENTIALS_MAX_ENTRIES=1

CONFIG_NANOPB=y

CONFIG_BT_WIFI_PROV=y
CONFIG_BT_WIFI_PROV_LOG_LEVEL_INF=y

CONFIG_WIFI_MGMT_EXT=y
# Setting BT supervision timeout to 75units (750ms) to avoid timeout of BT connection when radio is granted to Wi-Fi during scan.
CONFIG_BT_PERIPHERAL_PREF_TIMEOUT=75

# Similar to shell sample, add this option to ensure the event can get served.
CONFIG_NET_MGMT_EVENT_QUEUE_TIMEOUT=5000

Now we're ready to re-build our project and flash it to the DK. Click the Rebuild button, then Flash to the DK:

Rebuilding the project
Flashing the application

Step #6: Open a serial terminal program (such as PuTTY, minicom, Serial, or within nRF Connect Extension in VS Code):

Serial Terminal Output

Step #7: Launch the nRF Wi-Fi Provisioner mobile app:

Click each image below to expand.

Once the Wi-Fi scan results are back and shown to you, select the one you'd like the DK to connect to and scroll to the bottom of the screen to enter the password for the access point. From there, press "Set," and the phone will send a message containing the Wi-Fi network and the password to which to connect.

Once this is successful, the app will show that the device is now provisioned and connected to the Wi-Fi network.

Click each image below to expand.

And that's it! 🎉 Now you've provisioned your Wi-Fi device (the nRF7002 DK in this case) to connect to the Wi-Fi network of choice.

For more details on the Bluetooth LE packets involved and a live demo of the whole process, check out the video in the next section.

Video Tutorial and Demo

To see this in action, check out our demo video where we:

Conclusion

Wi-Fi is essential for IoT devices and deployments, but onboarding devices remains a major challenge. Traditional provisioning methods are often frustrating, inconsistent, and unreliable. Bluetooth LE simplifies this process, providing a seamless, secure, and user-friendly alternative. By eliminating network switching issues and offering real-time feedback, BLE ensures a smoother onboarding experience.

Nordic Semiconductor’s nRF70 series, combined with nRF Connect SDK, enables low-power, dual-radio IoT solutions that leverage BLE for onboarding and Wi-Fi for data transfer.

By adopting Bluetooth LE-based provisioning, developers can enhance user experience, reduce support issues, and streamline deployments.

Here are some important references and links to learn more about Wi-Fi provisioning, Nordic's Wi-Fi solutions, and Bluetooth LE-based Wi-Fi provisioning:

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