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Re: Andy's Postbag and random ebay links

Posted: Sat May 13, 2017 7:23 am
by ag123
i think those doppler radars (https://en.wikipedia.org/wiki/Doppler_radar) used a *fixed* frequency echo to make life easier doing the calcs, but as we are doing *tyre noise* the calcs may need to be more esoteric in terms of filtering and change detection (a few hz differences in doppler shifts) along with a huge noise spectrum, but perhaps that can be done as well :lol:

Re: Andy's Postbag and random ebay links

Posted: Sat May 13, 2017 7:25 am
by Squonk42
ag123 wrote:there are tons of touch panels for the modern smart phones hi-tech capacitive (multi) touch often with the controller
http://www.ebay.com/sch/i.html?_odkw=4+ ... l&_sacat=0
the only trouble is that often a google search for how to interface them tend to turn up a blank

hope someone can pester some of the manufacturers to release the specs then all our arduinos would become capacitive multi touch as well and cheap :lol:

Here is a dev board to adapt the iPod Nano v6 MiPi screen with capacitive touch panel:
http://www.techtoys.com.hk/Displays/SSD ... ch-EVK.htm

I would like to replace the bridge chip by an STM32, using the findings from:
http://www.electricstuff.co.uk/nanohack.html
https://www.mixdown.ca/redmine/projects ... og_Summary

Re: Andy's Postbag and random ebay links

Posted: Sat May 13, 2017 7:26 am
by ag123
nice :D

Re: Andy's Postbag and random ebay links

Posted: Sat May 13, 2017 8:12 am
by ag123
ahull wrote:
zoomx wrote:Maybe it's better a spectrogram app that can do this
Image

Nice.. what is the App?


oh googled this, it runs on PC though, i'd guess spectrogram is somewhat too compute intensive to run on embedded (arduino or android) :D
http://spek.cc/

oh incorrect, many more on google play :D
https://play.google.com/store/search?q= ... ram&c=apps
https://play.google.com/store/search?q=fft

Re: Andy's Postbag and random ebay links

Posted: Sat May 13, 2017 9:29 pm
by RogerClark
I looked on eBay and there seem to be small doppler radar modules for around 5 pounds (GBP).

These seem to use a device called a HB100.

Im not sure if they output a voltage which is dependant on the doppler shift or the frequency of the shift, which is apparenitly a few hundred Hz for someone walking.

Either way, they look like they are investigating.

Edit.

I just googled for HB100 Arduino and it looks like its all been done already using that module. Including various youtube videos

Re: Andy's Postbag and random ebay links

Posted: Sun May 14, 2017 7:02 am
by ag123
yup HB100 seem like something fun to combine with the andy's stm32duino O'scope :lol:


Re: Andy's Postbag and random ebay links

Posted: Sun May 14, 2017 9:46 am
by ahull
The module is pretty cheap, all I need now is the magic missing ingredient... Loads of spare time. :D
EDIT: The datasheet wouldn't hurt too, so here's a copy -> https://www.limpkin.fr/public/HB100/HB1 ... n_Note.pdf

Re: Andy's Postbag and random ebay links

Posted: Mon May 15, 2017 6:32 am
by zoomx
I found this old post about it

Making the electronics for a $7 USD doppler motion sensor
http://www.limpkin.fr/index.php?post/2013/08/09/Making-the-electronics-for-a-%247-USD-doppler-motion-sensor
It seems that this sensor needs some electronics.

Edit: this one has code and a schematic for the preampiflier for the low signal that came from this module.
https://www.youtube.com/watch?v=TwmwfbFrPk4

Re: Andy's Postbag and random ebay links

Posted: Fri May 26, 2017 2:10 am
by RogerClark
I found an even cheaper Doppler radio module, for $1 AUD (less than one GBP)

http://www.ebay.com.au/itm/262783104831

http://www.ebay.co.uk/sch/i.html?_from= ... or&_sop=12

I also found some info on github

https://github.com/jdesbonnet/RCWL-0516/

So. I've ordered 3 of them!

I may never get around to using them, but they should work as intruder detectors if not speed sensors

Re: Andy's Postbag and random ebay links

Posted: Fri May 26, 2017 8:49 am
by ag123
i think one of the members here actually posted a video on those cheap radar sensors :D
https://www.youtube.com/watch?v=9WiJJgIi3W0