SEN-24540 XM125 complete-board power consumption and battery runtime

Sensors
1

Hello SparkFun Technical Support Team,

I am considering purchasing five SparkFun Pulsed Coherent Radar Sensor – Acconeer XM125 Qwiic boards, SEN-24540, for a battery-powered proximity-detection project.

Each sensor unit will use:

  • SEN-24540 XM125 board
  • Seeed Studio XIAO ESP32-C3
  • Pololu S7V8F3 regulated 3.3 V supply
  • 3.2 V, 6000 mAh LiFePO₄ battery
  • Close-range distance detection at approximately 20 cm
  • Target operating time of at least 14 days

Could you please clarify:

  • Do you have measured current-consumption figures for the complete SEN-24540 board, rather than only the XM125 module?
  • What is the current when powered through the 3.3 V/Qwiic input, with USB-C disconnected?
  • What is the complete-board current during close-range distance detection at approximately 10 measurements per second?
  • What is the current when the XM125 is placed into its lowest-power state through WAKE_UP?
  • Does the onboard CH340C enter a low-power or USB-suspend state when the board is externally powered at 3.3 V and no USB cable is connected?
  • What is the approximate CH340C current in that condition?
  • Does cutting the LED jumper completely disconnect the power LED?
  • Should the WU jumper be cut when WAKE_UP is controlled by an ESP32-C3 GPIO?
  • Are there any other hardware modifications or firmware settings recommended to minimize average current?
  • Have SparkFun or customers measured battery runtime or complete-board current in a similar application?

The most useful test conditions would be:

  • Direct 3.3 V/Qwiic power
  • USB-C disconnected
  • LED jumper cut
  • Approximately 10 Hz close-range distance detection
  • XM125 low-power state
  • CH340C left installed

These figures will determine whether the board can meet the 14-day operating target before I purchase five units.

Thank you,
Mohsen

2

We haven’t tested these as described…I rarely even see industrial-rated products with those type of specs known/provided, but I’ll try to run through these nevertheless

  • Do you have measured current-consumption figures for the complete SEN-24540 board, rather than only the XM125 module?
    No

  • What is the current when powered through the 3.3 V/Qwiic input, with USB-C disconnected?
    If tested/known it’d be in the tech specs…the acconeer docs are somewhat sparse themselves https://docs.sparkfun.com/SparkFun_Qwiic_Pulsed_Radar_Sensor_XM125/assets/component_documentation/XM125_datasheet-3133248.pdf
    https://docs.sparkfun.com/SparkFun_Qwiic_Pulsed_Radar_Sensor_XM125/assets/component_documentation/A121%20datasheet.pdf

  • What is the complete-board current during close-range distance detection at approximately 10 measurements per second?
    This’ll depend on a ton of factors, you’ll likely be much better off grabbing one unit and testing this as you’d like done but here’s their guess (at the given measurement distance)

    image
    image869×524 72.6 KB
    , plus the mentioned LDOs & CH340C, LEDs, etc…not too much!

  • What is the current when the XM125 is placed into its lowest-power state through WAKE_UP?
    Untested

  • Does the onboard CH340C enter a low-power or USB-suspend state when the board is externally powered at 3.3 V and no USB cable is connected?
    no cable → no enumeration → no suspend logic engaged → chip just draws its normal idle operating current the whole time, not a special reduced-power mode

  • What is the approximate CH340C current in that condition?
    Again, this is better tested…I’d be guessing based on MFR reported specs which I find to be wrong too often to trust

  • Does cutting the LED jumper completely disconnect the power LED?
    Yes

  • Should the WU jumper be cut when WAKE_UP is controlled by an ESP32-C3 GPIO?
    Yes Hardware Overview - SparkFun Qwiic Pulsed Coherent Radar Sensor Breakout - Acconeer XM125 Hookup Guide

  • Are there any other hardware modifications or firmware settings recommended to minimize average current?
    Disabled the onboard LEDs and using triggers/interrupts with low-power mode is most of it…closer measurement distances cost less power

  • Have SparkFun or customers measured battery runtime or complete-board current in a similar application?
    Not at all, really…but we sell USB Power Meter (Color TFT LCD) - SparkFun Electronics which along with 1 unit you suit your testing needs fairly well