The technique used by Swedish Institute of Computer Science looks sound=20
on the surface. I just wonder whether the variations are really caused=20
by multi-path conditions. I didn't read far enough to see whether the=20
internals of the rf chip automatically generating an ack were=20
considered, nor do I know if the chip manufacturers disclose that info. =20
The researchers seem to consider the rf chip an ideal black box.
My guess is that internal to the rf chip, there are the same clocking=20
and latency issues that would exist in the platform microcontroller.
Did I not read far enough?
Joe W
On 1/25/2015 3:18 AM, RussellMc wrote:
> RF Time of flight distance measurement for position location using Arduin=
o
> - Superb & arcane - he is pushing what he has far above normal
> capabilities. Very intelligent application of laws of Physics.
>
>
>
>
> Adam Fabio posted: "If you carry a cell phone with GPS, you always kn=
ow
> where you are on the planet. But what about inside buildings or even your
> own home? Knowing if you're in the kitchen or the living room would be a
> great feature for home automation systems. Lights could " Respond to
> this post by replying above this line
> New post on *Hackaday*
> Trinket
> uses RF to track you through the house
>
> by
> Adam Fabio
>
> If you carry a cell phone with GPS, you always know where you are on the
> planet. But what about inside buildings or even your own home? Knowing if
> you're in the kitchen or the living room would be a great feature for hom=
e
> automation systems. Lights could come on as you enter the room and your
> music could follow you on the home audio system. This is exactly the what
> [Eric] is working on with his Radiolocation using a Pocket Size Transceiv=
er
> project. [Eric] started this project as =
an
> entry in the Trinket Everyday Carry Contest. He didn't make the top 3, bu=
t
> was one of the fierce competitors who made the competition very hard to
> judge!
>
> The heart of the project is determining Time Of Flight
> (TOF) for a radio signal.
> Since radio waves move at the speed of light, this is no small feat for a=
n
> Arduino based design! [Eric] isn't re-inventing the wheel though - he's
> basing his design on several research papers, which he's linked to his
> project description . Time of
> flight calculations get easier to handle when calculating round trip time=
s
> rather than one way. To handle this, one or more base stations send out
> pings, which are received and returned by small transponders worn by a
> user. By averaging over many round trip transmissions, a distance
> estimation can be calculated.
>
> [Eric] used a Pro Trinket as his mobile transponder, while an Arduino Mic=
ro
> with it's 16 bit counter acted as the base station. For RF, he used the
> popular Nordic nRF24L01+ 2.4 GHz transceiver modules. Even with this
> simple hardware, he's achieved great results. So far he can display
> distance between base and transponder on a graph. Not bad for a DIY
> transponder so small if fits in a 2xAAA battery case! [Eric's] next task =
is
> working through multipath issues, and testing out multiple base stations.
>
> Click past the break to see [Eric's] project in action!
>
> Read more of this post
>
> *Adam Fabio * | January 24, 201=
5
> at 10:00 am | Tags: hackaday.io ,
> radar , Radicalization
> , Trinket EDC contest
> | Categories: Arduino Ha=
cks
> , contests
> | URL: http://wp.me/pk3lN-BCG
>
> Comment
>
> See all comments
>
> Like
>
--=20
Joe Wronski
jwronski@stillwatereng.net
www.stillwatereng.net
--=20
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