# mmWave C4001 24GHz Human Presence Detection Sensor (SEN0609)

**URL:** <https://forum.core-electronics.com.au/t/mmwave-c4001-24ghz-human-presence-detection-sensor-sen0609/24351>\
**Category:** Core Electronics\
**Created:** [3 August 2026 02:32 UTC](https://forum.core-electronics.com.au/t/mmwave-c4001-24ghz-human-presence-detection-sensor-sen0609/24351 "2026-08-03T02:32:11Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Chanchal326580](https://avatars.discourse-cdn.com/v4/letter/c/ecae2f/32.png) [@Chanchal326580](https://forum.core-electronics.com.au/u/Chanchal326580)\
**Post date:** [3 August 2026 02:32 UTC](https://forum.core-electronics.com.au/t/mmwave-c4001-24ghz-human-presence-detection-sensor-sen0609/24351/1 "2026-08-03T02:32:11Z")

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I’m exhibiting at the World Trails Conference in October, where I’ll have a 1×2‑metre booth located in the main common area — the space where attendees gather for coffee, drinks, and general networking.

My campaign focuses on the idea that trails are shared spaces for everyone: horses, pedestrians, cyclists, and other users. The message is simple and friendly — **“Go slow and say hello.”**

To bring this to life at the booth, I want to set up a playful, interactive speedometer. As people approach, it will detect their walking speed: if they’re moving at a relaxed, normal pace, the display will show a smile; if they’re walking faster than usual, it will switch to a frown. It’s a light‑hearted way to reinforce the idea of slowing down and sharing the trail respectfully.

I’m developing this concept as part of my work with ATHRA ([https://www.athra.com.au/](https://www.athra.com.au/)).

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**Author:** ![Donald23173](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/donald23173/32/12687_2.png) [@Donald23173](https://forum.core-electronics.com.au/u/Donald23173)\
**Post date:** [3 August 2026 11:15 UTC](https://forum.core-electronics.com.au/t/mmwave-c4001-24ghz-human-presence-detection-sensor-sen0609/24351/2 "2026-08-03T11:15:30Z")

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Hi ! Interesting idea 😃

My first thought is to wonder whether frowning at someone approaching your booth might be perceived as unfriendly - especially if they feel you are judging them.

Also, have you thought through where your sensor will be located, its range (distance) and width ? Will it be detecting single individuals, or groups of passers by ? On those occasions manning a booth I have noticed periods with very few people wandering aimlessly around the booths, and other times when you might get a dozen people within the sensors detection zone.

I don’t mean to be negative - but years in IT showed me that a bit more planning can save a lot of effort down the track.

I really liked [Jared’s video](https://core-electronics.com.au/guides/raspberry-pi/using-mmwave-radar-to-detect-and-track-humans-raspberry-pi-guide/) and bought a mmWave radar module … but not used it yet myself, so will be interested to hear your experiences.