Subject: Troubleshooting C1001 mmWave Sensor: Human Presence & Fall Detection Errors
nikhilBhat 2025-04-19 04:53:23 154 Views5 Replies Hello DFRobot Support Team,
I’m integrating the C1001 mmWave Human Detection Sensor into my fall‑detection project but have run into a few issues and would appreciate your guidance.
1. Human Presence Issue
Even when no one is in the room or very far away , the LED is on and the web page reports that a human is present. Do you think the sensor has gone bad? It wasn’t like this before. Do you think it could be an ESD issue? I’ve taken the necessary precautions—using an ESD cover and handling the module by its edges.
2. Fall Detection Issue
The sensor never transitions to “Fallen,” even when a person remains on the floor for several minutes or actually falls. These are my current settings:
hu.dmInstallHeight(270); // Sensor mounted 270 cm above ground
hu.dmFallTime(5); // Wait 5 s before confirming a fall
hu.dmUnmannedTime(1); // Wait 1 s before reporting “no one present”
hu.dmFallConfig(hu.eResidenceTime, 200); // 200 s of stillness = “stationary dwell”
hu.dmFallConfig(hu.eFallSensitivityC, 3); // Maximum fall sensitivity
hu.configLEDLight(hu.eFALLLed, 1); // Enable fall‑status LED
hu.configLEDLight(hu.eHPLed, 1); // Enable presence‑status LED
hu.sensorRet(); // Apply settings
Are there any additional parameters or calibration steps I should adjust to improve fall‑detection reliability?
3. Enclosure Concerns
We plan to enclose the sensor in a 3D‑printed PLA case. Could you please advise on:
Material penetration: Will the radar pulses reliably penetrate standard PLA palstic?
Antenna clearance: Is there a recommended minimum distance between the sensor’s antenna and the inner surface of the case?
Case thickness: What wall thickness (if any) do you recommend to minimize signal attenuation?
I currently have this 3d case printed :
4. Soldering Precautions
Are there any precautions I need to take or new considerations when soldering the module onto the board via header pins?
We are participating in a global competition and our idea has been selected. May 5 is the deadline, so your quick support would be highly appreciated. Here is the link to our project:
https://www.hackster.io/nikhilbhatprofessionemail24/sentinel-fall-smart-radar-ble-based-fall-detection-system-265fd4
https://www.hackster.io/contests/board-designer
Thank you very much for your assistance and any tips you can share.
Best regards,
Nikhil Bhat
files_cq001.zip It might be worthwhile to re-check the sensor’s calibration. Over time, the sensor’s behavior may drift, and recalibration could help restore normal performance.
ahsrab.rifat Hi,
Thanks for the suggestion. Just to clarify, I’ve barely used the sensor so far, and it's already exhibiting unexpected behavior — so I’m a bit surprised that recalibration might be necessary this early.
If recalibration is still recommended, could you please guide me through the correct procedure for doing so? Also, for your reference, I’ve been powering it with a stable 5V supply.
Looking forward to your advice.
Best regards,
Nikhil Bhat
Hi, the operating voltage of C1001 is 5V DC.
This is because the RF circuitry on the board needs 5V to work at optimal operating conditions.
So the 3.3V supply may not be enough.
Yeez_B Hi,
Thanks for confirming the 5V requirement—I’ve adjusted the supply accordingly.
Regarding the enclosure, I’ve placed the radar inside a PLA case with 2.5mm wall thickness. Human presence detection is working well, but I’m unsure if this setup could affect fall detection or cloud point algorithms. Could you confirm if 2.5mm PLA is acceptable, or suggest a more suitable thickness or material?
Also, is there a recommended minimum clearance between the antenna and the inner surface of the case?
Lastly, are there any soldering or ESD precautions I should be aware of when handling the module?
Appreciate your support!
Best regards
Ok, tried it again today.
Presence is working fine now — I believe the issue was due to an improper voltage supply (I gave 3.3V). But fall still isn't working. I’ve even set the proper height (2.2 m) and max sensitivity.
nikhilBhat 
