A121 60GHz mmWave Radar Distance, Speed and Motion Sensor

The Waveshare A121 Range Sensor Box is a fully enclosed 60 GHz mmWave radar sensor based on Acconeer A121 Pulsed-Coherent-Radar Technology (PCR) for presence detection, micro-motion detection, and high-precision distance measurement. Unlike the bare module format, the sensor comes in a finished plastic casing with an integrated Fresnel lens that optimizes the radar detection characteristics and protects the PCB from dust and mechanical influences. An integrated STM32L431CBT6 ARM Cortex-M4 microcontroller enables standalone processing directly on the sensor or communication with an external host via UART, I2C, or GPIO.

Features:

• Acconeer A121 60 GHz PCR radar sensor with integrated baseband, RF front-end, and AiP antenna in a compact 39 × 39 mm board for precise distance measurement and micro-motion detection
• Integrated STM32L431CBT6 ARM Cortex-M4 @ 80 MHz allows standalone operation with Acconeer RSS or communication with external host via UART, I2C, or GPIO
• Finished plastic casing with Fresnel lens (3301PA) protects the module and optimizes detection characteristics without own casing development
• Behind-Plastic and Behind-Glass installation possible – the sensor operates reliably behind surfaces without visible opening
• Dual USB-UART via CH342 for simultaneous access to Exploration Tool (Port A) and data output (Port B) via a single USB-C cable
• Operating temperature range -40 to 85 °C for industrial and outdoor use even under extreme environmental conditions

Application examples:

• Presence detection in smart home and building automation – reliable detection of people without a camera for privacy-compliant solutions
• Contactless control and proximity sensing for devices, displays, and machines through proximity and gesture recognition
• Vital signs monitoring – detection of breathing rate and micro-movements behind a wall cladding
• Industrial distance measurement and equipment protection without light sensitivity, resistant to dust and dirt
• Speed measurement of vehicles or people at entrances and conveyors through continuous real-time distance evaluation
• Robotics and autonomous systems – precise distance and movement detection as input for navigation and collision avoidance

Documentation:

• Waveshare Wiki – A121 Range Sensor

Technical specifications:

• Manufacturer: Waveshare
• Manufacturer SKU: 33778
• Radar sensor: Acconeer A121 (60 GHz PCR, integrated baseband + RF + AiP antenna)
• MCU: STM32L431CBT6, ARM Cortex-M4 @ 80 MHz, 128 KB Flash, 64 KB RAM
• Frequency: 60 GHz
• Technology: Pulsed Coherent Radar (PCR)
• Interfaces: UART (standard baud rate 921600), I2C (address 0x52, adjustable 0x51/0x53), GPIO
• USB: USB-C with dual UART CH342 (Port A: ExplorationTool / Port B: Data output)
• IO supply voltage: 3.3 V
• Installation: Behind-Plastic / Behind-Glass compatible
• Lens: Fresnel lens made of 3301PA material (integrated in the casing)
• PCB dimensions: 39 × 39 mm
• Operating temperature: -40 to 85 °C
• Firmware: UART, I2C, and Exploration Tool variants available
• Programming environment: Acconeer RSS, Acconeer ExplorationTool, Python, Raspberry Pi
• SWD pads: Available for development and production programming
• Packaging dimensions: 80 × 70 × 29 mm
• Gross weight: 37 g

Scope of delivery:

• 1× A121 60GHz mmWave radar distance, speed, and movement sensor
• 1× USB-C cable