Michael | Aug. 3, 2020

Ships from China

You say that you ship from Switzerland. So I payed for that. But I received the shipping information that my package will be received from China (Shenzhen). It usually takes much longer for packages to arrive from China. Strictly speaking, it would not be part of the sales contract. I need the sensor, so I'll have to wait. That is annoying. The shipping costs are therefore not conclusive and transparent for me. Especially since half of the order was almost the shipping costs.

Response from limpkin | Aug. 3, 2020

Hello!
We're very sorry you got that impression... in the HB100 product description is mentioned " Shipping will be done from Switzerland or Shenzhen depending on current stock and customer location."

Mohd | March 20, 2020

HQ Product, Fast Shipping, Useful Doc.

Hi limpkin,
first of all thank you for fast shipping, but i paid two shipping fee and get it in same box :)

I've question, in CODE you use "19" for HB100 , and for CDM324 use "44" ..

From where you get this constant??

Response from limpkin | March 20, 2020

Hi there!
Could you send me a quick message in private? I'll refund part of your other shipping fee... as this was due to 2 different orders on 2 different stores :).
The different values are because of their different operating frequencies! Have a look here: https://github.com/limpkin/cdm324_backpack/tree/master/datasheets_module

Thanks for your review!

Tanel | Nov. 18, 2019

Bernardo | Oct. 31, 2019

Very good!

Hello!
The hb100 that I bought you has good reading range. But the sensors that I get here in Argentina, are different and have little reading range, only 2 meters.
For example, yours is "ZH100" and those here are "MX100" or something similar.
Do they change anything?
The screw it brings, what is it for?
Would it serve to adjust the distance of the sensors that I get in my country?

Response from limpkin | Oct. 31, 2019

Hello!
I'm afraid I'm not familiar with these MX100...

Alexander | Dec. 1, 2018

questions about FOUT )

Hi... I recently purchased this module for detection moving people in the room.
External view of module is very good, and from VOUT output i have useful signal (>2.5V wheh i moved)
But I have a questions.
1) If I have not moving in room with your sensor, what sighal i have in FOUT ?
I think 0, but i have not null frequency.
2) And you in your speed measure's sample for arduino you connect FOUT to digital input of arduino.
But output FOUT of sensor is analog signal, isn't it ?
Why he is connected to digital input ?

Response from limpkin | Dec. 1, 2018

Hello,
1) You'll see noise on the FOUT output, which is why it is important to make sure that VOUT is relatively high to take into account FOUT.
2) FOUT is digital, VOUT is analog.
Would you modify your text content with a review? Thanks!

Kok | June 28, 2018

Aditya | Dec. 11, 2017

Daniel | Nov. 27, 2017

Martin | Aug. 24, 2017

Joseph | Aug. 31, 2016

Seller should post simple testing code. Works ok, not great

Purchase was easy and shipping was very fast with great tracking.
Hooked this up to a breadboard that I also tested the parallax microwave doppler, and another brand from China on. This one had some problems. It sends a continuous signal and doesn't stop, even when there's no motion. I checked the hook up wires to the board and they are correct. Not sure why it's doing this. I used the same exact program and ardiuno uno microprocessor as for the parallax and china models. It might be something in the programming, not sure, but as of right now, I am not able to use this 'tindie' sensor. Hopefully it just needs an adjustment somewhere, maybe in the programming. I did take notice the difference in sensor structure, this one being an HB100 and the other two being GH-719. Not sure if that has anything to do with it.
**It would be extremely helpful if the seller could post some simple testing code for arduino.**

Response from limpkin | Aug. 31, 2016

Hello Joseph,

I'm very sorry about your experience and would have wished you'd have contacted me before to request assistance for your project, as I'd be more than happy to help you.
I'll provide a sample code on this page soon.

Regards,
Mathieu

Rene | Aug. 16, 2016

Nigel | July 28, 2016

Overall A Good Board

Just interested in seeing how doppler radar works.

Concentrating on the digital output, I certainly see a change if I walk away or toward the unit at different speeds, but I cannot correlate the speed to a 'scope frequency.

Very wary about write microcontroller code for this as things are the moment.

Response from limpkin | July 28, 2016

Hello,

Could you double check your complete setup? You should get the exact same behavior shown in the demonstration video.
Because of the way the Doppler effect works, the only reason for a given output signal frequency is the speed of the object moving in front of the sensor.

Regards

Solène | May 30, 2016

Need help

Hello i have read the documentation and i think the high pass filter is to low
I would to make car speed mesurment and the velocity is 60km/h.
Your filter is designed for 72hz?
Thanks for your reply

Response from limpkin | July 12, 2016

Hello,
Actually if the sensor is right in front of the car you'll be able to measure high speeds. Have a look at this web page for reference:
http://www.limpkin.fr/index.php?post/2013/08/09/Making-the-electronics-for-a-%247-USD-doppler-motion-sensor

Regards,
Mathieu

Jean-Luc | May 4, 2016

HB100 breakout board

Hello.
Good delivery, good design.
I did not try the module yet.
On the board is written VOUT and FOUT.
I presume that those signals are prop to the speed.
But could somebody tell me if VOUT = 5VDC -----> SPEED (MPH),
or if FOUT = 32 Hz ------> SPEED (MPH) ?
Thanks for your support !
Best regards,

Jean-Luc

Response from limpkin | May 4, 2016

Hello,

Thanks for the review!
Please have a look at the application note: http://www.limpkin.fr/public/HB100/HB100_Microwave_Sensor_Application_Note.pdf

Regards

Stefano | Feb. 25, 2016

Jared | Jan. 29, 2016

Jean-Jacques | Dec. 16, 2015

Romero | Aug. 17, 2015

Josh | July 14, 2015

Joseph | June 7, 2015

Everything works, but I think the bandwidth is off.

First, the unit performs exactly as designed, is well built, shows a high level of professionalism in design and execution. I used it immediately to detect movement in the room. It's sensitive enough to detect a heartbeat up close. It also reacted to rainfall outside the window. So as a detector, it certainly works, although it's difficult to discriminate and determine precisely what is being detected. It also has limited range of about ten feet indoors.

Based on the excellent documentation and product description done by Limpkin, I expected to be able to use this device to detect people moving at about 40 feet away. Unfortunately, the amplifier upper cutoff frequency is set a bit low, so the signal to the detector is already down from maximum gain by quite a bit at 100 Hz. The average person walking at 3.1 mph would generate a Doppler frequency of about 93 Hz. In fact, the signal will vary from about 60 Hz to about 100 Hz over the course of a single step, with additional frequency components at twice those frequencies due to arm and leg motion. With the bandwidth set low, it becomes more difficult to detect people moving at some distance. For this, I believe I will need another amplifier design, and I'll need to use the analog Doppler signal through FFT's to discriminate between people and other moving objects at some distance.

Response from limpkin | June 11, 2015

Hello Joseph,

Thanks a lot for the awesome review. Heartbeat detection is neat idea!
Let me know if you need a hand for this other amplifier design...

John | Jan. 12, 2015

Tarek | Dec. 13, 2014

Paul | Oct. 20, 2014

Still hasn't turned up

Dying to try it out BUT
Said it was sent by registered post -

Response from limpkin | Oct. 20, 2014

Hello Paul,

Are you sure? tracking says you received it today: http://www.17track.net/en/result/post-details.shtml?nums=RX572403294DE

Philip | Oct. 14, 2014

Gedeon | Oct. 1, 2014

Iliya | Oct. 1, 2014

Noah | May 24, 2014

Charles | Dec. 6, 2013