Bluetooth 5.2/Bluetooth LE module for IoT radar distance ranging apps

IoT module from Acconeer employs Nordic’s nRF52840 SoCam

Lund, Sweden-based Acconeer, a developer of high tech sensor-based solutions, has selected Nordic’s nRF52840 Bluetooth 5.2/Bluetooth Low Energy (Bluetooth LE) advanced multiprotocol System-on-Chip (SoC) to power its ‘XM122 IoT Module’.

The module combines the Nordic SoC with the ‘A111 Pulsed Coherent Radar’, enabling millimeter-level radar distance ranging and presence detection in a wide range of applications, such as tank level or waste bin measurements, gesture detection, or parking lot capacity sensing.

The XM122 IoT module was developed as a reference module that can be used to support developers in their designs for commercial use, as well as for evaluation and development purposes when used in conjunction with the company’s ‘XB122 Breakout Board’. Acconeer has also collaborated with Imagimob, an Edge AI company, to produce a gesture-controlled headphone demonstration using the XM122 IoT Module. The module runs an Imagimob AI model trained to recognize five hand gestures to control headphone operation.

Nordic SoC’s 64MHz, 32-bit Arm Cortex M4 processor with floating point unit (FPU) ensures the XM122 module can support complex IoT applications. The nRF52840 SoC’s Bluetooth 5.2 functionality enables developers using the module to take advantage of Bluetooth Long Range and increased throughput (2Mbps) in demanding IoT use cases. Bluetooth 5 Channel Selection Algorithm (CSA #2) enhances the module’s immunity to interference from other 2.4GHz RF signals. Such immunity enhances link robustness, limiting packet retransmissions and saving power – making the module suitable for use in challenging RF interference environments.

The XM122 IoT module is packaged in a 33-mm circular form factor and features an integrated 2.4GHz antenna, support for an external 2.4GHz antenna, as well as an optional NFC antenna to aid initiation of quick Bluetooth LE pairing. The module supports an operating voltage range from 2 to 5.5V, and can be operated from, for example, a standard CR2477 coin cell battery. Battery life varies depending on the application, but in certain use cases can run to several years, thanks to Acconeer’s ultra low power pulsed coherent radar technology and the ultra low power operating characteristics of the nRF52840 SoC. According to Nordic, the SoC has been engineered to minimize power consumption with a fully-automatic power management system. The XM122 module is specified over the full industrial –40º to 85º C operating temperature range.