SparkFun Pulsed Coherent Radar Sensor - Acconeer XM125 (Qwiic)

Forget ultrasonic and infrared sensors; the SparkFun Qwiic Pulsed Coherent Radar Sensor - Acconeer XM125 brings powerful 60 GHz radar technology to your projects. This sensor isn't limited to surface detection; it can see through walls, cabinets, and even pockets (depending on the material), making it perfect for unique applications. Measure distances with millimeter precision, detect motion, the speed of an object, or even gestures!

The XM125 boasts an impressive range of up to 20 meters, allowing you to create long-range sensing projects. The actual measurable distance is dependent on the object size, shape, dielectric properties, and lens (e.g. water level measurements up to 20 meters with lens utilization, human presence detection up to 7 meters with lens-free utilization). Despite its power, the sensor has remarkably low in power consumption, which is ideal for battery-powered applications. The real magic lies in the sensor's ability to do more than measure distance; the XM125 can differentiate between stationary objects and moving targets using pulsed coherent radar. This means you can sense an object's presence and how fast something is moving!

We've included a USB type-C connector, ESD protection diodes on the USB data lines, and a CH340C USB-to-serial converter to connect the XM125 directly to your computer's COM port. Power is regulated down for the XM125 with the AP2112K 3.3V/600mA and RT9080 1.8V/600mA voltage regulators. Buttons for reset and boot are included when resetting the module or setting the board into bootloader mode. Utilizing our handy Qwiic system, no soldering is required to connect it to the rest of your system. However, we still have broken out 0.1in.-spaced pins if you prefer a breadboard.

We've written an Arduino library when the I2C presence or distance detection firmware is loaded onto the XM125 module. With the I2C presence detection firmware, you can sense when an object is moving in an environment and how far away it is from the sensor. You can detect slow and fast movements with the inter-presence and intra-presence scores, respectively. The I2C distance detection firmware is similar to the presence detector by providing distance measurements. However, distance detection will provide information when it detects objects within range. The distance detection firmware can also adjust the sensor's threshold and sensitivity. The read range can also be configured to a certain distance away with either firmware.

Acconeer has also developed a visualization tool written in Python that demonstrates data collection in real time. The Acconeer Exploration Tool is an incredible resource, especially when starting out with the XM125 module to debug and explore the sensor's capabilities. This allows you to fine-tune the sensor for your application. For example, it will graph distance or presence sensing, giving you a count of the number of sweeps, which communication port data is being sent through, and much more. It will also guide you to the optimal sensor settings and help you fine-tune the data processing for your final product implementation. The tool supports Windows and Linux and requires Python version 3.8 or later. This tool is available through their GitHub Repository. Head on over and take a look!

With the SparkFun Qwiic Pulsed Coherent Radar Sensor, a world of new project possibilities opens up. Imagine creating presence detection systems for smart homes and security applications, parking space occupancy detection, gesture recognition interfaces for unique user control, level measurement (for example, in tanks or waste containers), through-wall imaging systems for search and rescue, or even advanced robotics with object avoidance and navigation.

Note: Due to the higher frequencies, pulsed coherent radar sensors may be regulated in certain countries. Be sure to check local regulations before use.

The SparkFun Qwiic Connect System is an ecosystem of I2C sensors, actuators, shields and cables that make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector. This reduces the amount of required PCB space, and polarized connections mean you can’t hook it up wrong.

  • 1x USB Type C Connector
  • ESD Protection Diodes for USB Data Lines
  • CH340C USB-to-Serial Converter
  • Voltage: 5V or 3.3V but all logic is 3.3V
  • AP2112K 3.3V/600mA Voltage Regulator
  • RT9080 1.8V/600mA Voltage Regulator
  • Acconeer XM125 Module
    • A121
      • 60GHz Pulsed Coherent Radar (PCR)
      • Integrated Baseband, RF Front-End and Antenna in Package
      • Detect Distance, Speed, Motion, and Objects up to 20 Meters** Away
      • Millimeter Precise Readings
      • Low Power Consumption
    • STMicroelectronics STM32L431CBY6
      • 32-bit Arm® Cortex® M4 MCU
      • Clock Speed: 80 MHz
      • Flash: 128kB
      • RAM: 68kB
  • 2x Horizontal Qwiic Connectors
  • Built-in I2C 2.2kΩ Pull-Up Resistors
  • I2C Address: (0x52, Default)
  • 2x5 SWD Header Footprint
  • Buttons
    • Reset
    • Boot
  • LED
    • Power
  • Jumpers
    • USB Shield (SHLD)
    • Power LED (LED)
    • I2C Pull-Up Resistors (I2C)
    • Wake Up (WU)
    • I2C Address (ADDR)*
  • Board Dimensions: 1.0" x 2.0" (25.4mm x 50.8mm)
  • Weight: 6.35g

*Note: Selectable I2C address to be implemented in the future.

**Note: The actual measurable distance is dependent on the object size, shape, dielectric properties, and lens (e.g. water level measurements up to 20 meters with lens utilization, human presence detection up to 7 meters with lens-free utilization).

SparkFun Pulsed Coherent Radar Sensor - Acconeer XM125 (Qwiic) Product Help and Resources


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • Member #281885 / about 4 months ago / 1

    regarding sensing distance from SparkFun tutorial: "... water level measurements up to 20m with lens ..." Have seen no refs anywhere about what kind of "lens" they're talking about, not even in Acconeer pdf. Any ideas?

    • Member #281885 / about 4 months ago / 1

      more searching found LH132 lens kit, about $37 from Digikey:

  • Member #202208 / about 4 months ago / 1

    Can both USB and I2C be used at the same-ish time? I'm thinking in particular where a microcontroller detects an initial event and then boots another more powerful device that could then use the USB connection to do other functions.

  • Member #281885 / about 4 months ago / 1

    In the acconeer github page, I didn't immediately see software for running it on Linux. Did I just miss it?

  • Member #630068 / about 4 months ago / 1

    Would anyone care to speculate how a fiberglass RV trailer wall might influence the sensing range?

    • Hmm, fiberglass is made up of plastic and glass so I would assume that there would be some loss in range similar to both of those materials. I'm not sure of the specifics since I have not tested the XM125 with fiberglass from an RV trailer. Acconeer lists some materials through their handbook along with some of their relative permittivity. However, they do not list the range.

      It would be best to test to make sure and ensure that there is no metal between the sensor, fiberglass, and object that you are trying to detect. =)

  • ulrikkau / about 4 months ago / 1

    Does the XM125 really have a 20 m range? I can only read 2m in the datasheet of XM125

    • BerenV / about 4 months ago * / 1

      From the A121 datasheet: “The A121 is based on leading-edge patented pulsed coherent radar technology with pico- second time resolution. The sensor can measure up to 20 meters and the actual measurable distance is dependent on object size, shape, and dielectric properties. For example: • Water level measurement up to 20 meters with lens utilization • Human presence detection up to 7 meters with lens-free utilization”

      It sounds like 20m is highly idealized, and that kind of performance is not possible with all target materials. I also don’t see anything in the XM125 datasheet about anything over 2.75m. I wonder if the XM125 is a breakout board for evaluation and short range purposes and you need a more advanced board/antenna to hit those 20m ranges the A121’s datasheet mentions.

Customer Reviews

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Not very good

I can't get any useful readings out of it. It does seem to detect movement occasionally but it normally just reads 30mm and if I move towards the sensor sometimes it will read a different number then go back to 30 mm. I have also tried the distance measurement firmware and it isn't any better. I have had much better results with other sensors.