This Week in Bluetooth & UWB

April 24, 2026

In This Issue

→ ESP32-S31: RISC-V + Bluetooth 5.4
→ Real-world Bluetooth LE throughput
→ AirTag locations get spoofed
→ ST ships 802.15.4ab UWB chips
→ UWB in pill-sized cameras

What I'm Working On

Bluetooth LE Unplugged launched this past Monday 🚀 — the hands-on course that teaches the protocol through AT commands with two USB dongles shipped to your door. 96 lessons across 15 modules. No SDK, no toolchain, no barriers.

Want a peek first? Preview the curriculum and sample lessons →

Espressif Bundles Wi-Fi 6, Bluetooth 5.4, and HMI Into RISC-V SoC

All About Circuits

Espressif Systems recently announced the upcoming release of the ESP32-S31, a dual-core system-on-chip with integrated wireless and wired connectivity. By consolidating Wi-Fi 6, Bluetooth 5.4, and IEEE 802.15.4 onto a single silicon die, Espressif designed the ESP32-S31 to help engineers build complex devices such as smart speakers, industrial automation hubs, and voice-controlled appliances. The dual-core 32-bit RISC-V microcontroller operates at speeds up to 320 MHz, and one core features a 128-bit-wide data path with SIMD instructions to accelerate parallel processing. The SoC offers Bluetooth 5.4 support with Low Energy (LE) for high-quality audio streaming via the LC3 codec, Bluetooth Mesh 1.1 for device-to-device communication, and Bluetooth Classic (BR/EDR) for legacy audio compatibility.

Bluetooth LE throughput: Why real-world performance falls short of specs

EDN

Many Bluetooth LE applications depend on reliable, high-throughput data transfer between connected devices. Although the Bluetooth LE specification defines clear upper bounds on achievable data rate, measured throughput in real systems often falls well below these limits. Using the 2-Mbps PHY, the on-air time for a maximum-length data packet followed by its acknowledgment is approximately 1.4 ms; if a connection interval could be filled entirely with such packet exchanges, the resulting application-layer throughput would be approximately 170 KBps. However, the maximum number of packets allowed per event is not specified by the Bluetooth standard and is instead determined by the controller and stack implementation, which is why Bluetooth LE throughput as a function of connection interval is often non-linear.

Apple AirTag tracking can be misled by replayed Bluetooth signals

Help Net Security

Apple's AirTag is designed to help users track lost items by relying on a vast network of nearby Apple devices. New research shows that this same system can be manipulated to display locations where an AirTag has never been. The encryption protects identities but also prevents the system from checking whether the reported location is genuine. Researchers demonstrated a relay attack that takes advantage of this limitation: they captured Bluetooth signals from a test AirTag, then replayed the captured data from a different location using custom transmitters. If key rotation is paused, for example by removing the AirTag's battery, replayed signals can continue to produce location reports for up to seven days.

IndieSemiC Partners with Nordic Semiconductor to Launch Global-Ready Wireless Modules

TimesTech

IndieSemiC, an Indian semiconductor and chip design company, has partnered with Nordic Semiconductor to design and commercialize advanced wireless modules for next-generation connected devices. IndieSemiC has a range of certified RF modules including Bluetooth LE modules based on nRF52 and nRF54 series, multi-protocol modules supporting Bluetooth LE, Thread, Zigbee, Wi-Fi, and Matter, along with long-range, high-performance wireless modules. These modules act as the backbone for wireless communication to be widely used across applications such as smart home devices, wearables, healthcare devices, industrial IoT systems, smart metering, and automotive connectivity solutions.

Passive On-Device Bluetooth LE Interference Detection Using TinyML

Kettering University

Kettering University Computer Science student Cameron Jozwik '27 presented his paper, "Passive On-Device BLE Interference Detection Using TinyML," at the IEEE Conference on Secure and Trustworthy Cyberinfrastructure for Internet of Things and Microelectronics (SaTC 2026), as part of the conference's "AI for Smart Environments, Manufacturing, and Autonomous Systems" track. His research tackles a common but often overlooked problem: unreliable Bluetooth performance in crowded or signal-heavy environments. At its core, the project introduces a lightweight embedded system that enables devices to detect interference in near real time without relying on external infrastructure or added hardware.

ST Propels New Era of Ultra-Wideband Technology for Automotive and Smart Device Applications

TimesTech

STMicroelectronics introduces an ultra-wideband (UWB) chip family that comprehensively supports the next-generation wireless standard for localizing and tracking devices at distances up to several hundred meters. The three SoCs (ST64UWB-A100, ST64UWB-A500, and ST64UWB-C100) are built on 18 nm FD-SOI process that boosts link budget by nearly 3dB versus standard bulk technologies, extending range by roughly 50% beyond the gains delivered by the IEEE 802.15.4ab standard. The upgraded 1.3 GHz bandwidth of UWB channel 11 results in twice the accuracy compared to 500 MHz channels. Enhancements enabled by multi-millisecond ranging (MMS) and narrowband assistance (NBA) extend operating range, and IEEE 802.15.4ab also enhances radar mode, improving use cases such as child presence detection (CPD) in vehicles.

Creating a wireless tissue-aware medical device network in the human body

SciFacts / Osaka Metropolitan University

Diagnostic tests for stomach conditions are tough for patients, as many of the most accurate ones involve minor surgical procedures or invasive techniques. Swallowable medical devices have emerged as a possible solution. Wireless signals are made up of many frequencies, each of which gets absorbed, scattered, and distorted differently depending on whether it passes through muscle, fat, or bone. A research group at Osaka Metropolitan University focused on optimizing signal transmission separately for each frequency, allowing multiple implants to coordinate their signals using ultra-wideband (UWB) communication; the swallowed transmitter and relay devices adjust each frequency component so that all signals arrive aligned at the external receiver.

TU Graz Develops Navigation System for Underground Rescue Teams

TU Graz

In the NIKE MATE project, a research team consisting of Graz University of Technology (TU Graz), the University of Leoben, the Federal Ministry of Defence, OHB Austria and the Laabmayr Engineering Office has developed a system for missions where the technical infrastructure has collapsed due to explosions or fire. It combines sensor data from robots and rescue teams with a self-built UWB (ultra-wideband) network. The position information obtained is exchanged via a UWB transmitter with emergency personnel, who are themselves equipped with UWB tags and who place UWB anchors along their route. The anchors also enable distance measurements between all participants even without a direct line of sight, and the positions of robots and people can be determined with an accuracy of closer than one metre.

Canada's Spark Microsystems raises $12 million Series B

Evertiq

Spark Microsystems, a Canadian fabless semiconductor company specializing in next-generation short-range wireless communications, has closed a CAD 17 million (about USD 12 million) Series B follow-on financing co-led by Idealist Capital and Real Ventures, with participation from Cycle Capital, ND Capital and EDC. The investment will accelerate Spark's expansion and commercialization momentum for LE-UWB technology as customer demand surges for wireless solutions capable of meeting the performance and power requirements of increasingly intelligent edge devices. Spark sees soaring demand across wearables, gaming peripherals, industrial automation, smart buildings, and medical devices.