Originally Published in 2013 and Updated April 1, 2024: Bluetooth Low Energy (BLE) continues to evolve, and understanding the roles of the Generic Access Profile (GAP) and the Generic Attribute Profile (GATT) is crucial in leveraging this technology effectively. This updated article provides expanded information on GAP vs GATT and additional resources to support you on your BLE development journey. Introduction Bluetooth Low Energy (BLE) is a pivotal innovation in wireless technology, offering power efficiency and streamlined connectivity. Central to BLE’s functionality are the Generic Access ..read more

Table of Contents 35 minute read Introduction Building your first connected product is no easy task. There are many wireless networking protocols, each with its benefits and tradeoffs. However, if you’re interested in widespread support, including iOS or Android devices in your network, the Bluetooth Low Energy (BLE) protocol is the way to go. This Ultimate Guide to BLE Connectivity Architecture is primarily designed for engineers. Still, project managers and decision-makers can gain valuable insight as they reflect on their roles within this process. We’ll explore the foundational topics ..read more

Whether it’s your run-of-the-mill email phishing attack from a Nigerian prince, or a corporate scale data breach that leaks millions of people’s identifying information, all of us can probably recall a time where we’ve been the target of a cybersecurity attack in one form or another.  By now, most people are well aware of the need for taking proper security precautions while online and have probably even developed a pretty good spidey sense for shady activity.  If you’re developing a BLE-connected, or other embedded device that handles sensitive data or interacts with critical hardwa ..read more

What is a Bluetooth analyzer? And why you may need one.  Bluetooth protocol analyzers, also known as Bluetooth sniffers, are devices that capture and inspect radio transmissions on frequencies defined by Bluetooth specifications. Bluetooth Low Energy (BLE), in particular, broadcasts advertisements on 3 specified frequencies or channels while also utilizing 37 other channels to send data between already connected devices [1]. Because BLE payload data units (PDUs) vary in structure and content for different interactions across the 40 channels, mismatches in communication between devices can ..read more

Table of Contents 19 minute read One of the core aspects of designing a BLE application is determining how connections will be managed. There’s more to it than simply starting a connection whenever the devices should communicate. You must consider the following: When to advertise When to request connections How to make your devices available to connect When to disconnect How to limit connections Note that this blogpost covers the most common Bluetooth behaviors. The Bluetooth Specification describes advanced modes that won’t be discussed here. In most cases, those modes are not necessary ..read more

When you buy a Fitbit, you’re not just paying for the wearable hardware. You’re buying a key that unlocks access to a greater integrated system. Before you can even start using the device, you must first download the app, pair it with your phone, and create a user login.  Even a decade ago, it might’ve been completely untenable to require users to have an expensive smartphone to use a product. But today’s wireless devices take advantage of the fact that nearly everyone has a full-fledged Bluetooth Low Energy (BLE) and Internet of Things (IoT) bridge device somewhere on their bodies.  ..read more

When we talk about Bluetooth-connected devices, an inherent part of that discussion is bond management. Bond management consists of storing and deleting information about a paired device so that the pairing process between two authenticated devices doesn’t need to be repeated on every connection.  When we use wireless headphones, for example, we don’t have to go through the set-up steps every time we want to connect to our phones. Instead, it’s expected that we do it once, and the headphones will automatically connect to the phone when they’re within range of each other. Bond Management C ..read more

In many ways, I’m your stereotypical software engineer. I don’t do small talk, but I can talk for days about my work and side projects. I’m easily irked by inefficiencies — if it can be done more efficiently, why not do it that way? I also like to “fix” things like it’s my job (to be fair, it is my job from 8 to 5), and I spend what many people would consider “too much” time on /r/dataisbeautiful. You’ve surely heard one engineer or another say in jest, “the best engineers are lazy.” I know I have. What we really mean is those who have an eye for identifying inefficiencies and the drive to fix ..read more

Welcome to part 4 of the “Maximizing BLE Throughput” blog post series! This blog post will provide the key takeaways from our previous 3 posts and also bring us up-to-date with the latest BLE spec (such as 2M PHY). Update: Please check out our other blog posts in the Maximizing BLE Throughput series. You can find a lot of great information to better understand how BLE works and what factors affect transfer speed, DLE, etc. But be aware that some of the information in these posts may be outdated. Part 1: Maximizing BLE Throughput on iOS and Android  Part 2: Maximizing BLE Throug ..read more

Table of Contents 17 minute read This article assumes you know the very basics of Bluetooth Low Energy (BLE) and iOS programming (including the delegation pattern for asynchronous calls common to many iOS native APIs), and is meant as a comprehensive guide to the ins and outs of iOS’s Core Bluetooth library. We will walk you through the major components of the API, including the basic steps for scanning, connecting to, and interacting with a BLE peripheral, plus common pitfalls and things to know about BLE on iOS. App permissions Before you dive into code writing, you’ll need to configure ..read more