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khanh_an111
Joined: 25 Dec 2008 Posts: 15 Location: VietNam
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Posted: Tue Jan 20, 2009 3:15 am Post subject: |
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Hello all,
The distance from tag to antenna is about 5cm. But
The distance in 125KHz < 50cm.
How can I increase the distance?
Thank you very much. |
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ibilzh
Joined: 11 Jul 2007 Posts: 151 Location: Germany
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Posted: Tue Jan 20, 2009 10:51 am Post subject: |
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hello khanh_an111,
to increase distance cou can play with antenna, frequency, values of
the parts around the em4095.
But you will see at the end, that distance do not enlarge noticeable.
When you look to the datasheet of the EM4083 reader chip you can see,
that more coils bring more distance.
Result: a long distance reader.
Gerhard
Additional:
The priciple of long distance is others.
The reader integrates a high sensitivity low frequency AM receiver. |
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khanh_an111
Joined: 25 Dec 2008 Posts: 15 Location: VietNam
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Posted: Fri Feb 06, 2009 5:19 am Post subject: |
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Hello all,
I have two kit EM4095. But one of ATMEGA88 died.
In VietNam there is not ATMEGA88. But they have many ATMEGA8.
Can I replace ATMEGA88 by ATMEGA8?
Could you tell me how to replace?
Thank you very much.
Khanh An. |
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Evert :-)
Joined: 18 Feb 2005 Posts: 2156
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Posted: Sun Feb 08, 2009 5:38 pm Post subject: |
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ibilzh wrote: |
@evert
>There's a error in the drawing and parts list.
>Change CDV2 from 1N to 10N.
Why? Did you calculate it after spec sheet?
Gerhard |
Hi Gehard, Little late response but it's now a rainy day here in Holland and time to solve some longterm problems.
When assembling my kit it had 1x1N to short but there was a 10N extra in the partsbag.
Place the 1N out of my private stock and the kit was not working, then i replaced the 1N with the 10N and it was working.
Today i placed back the 1N and it's still working, so i looks to me that when assembling the kit i was not sharp enough and changed something else that did the kit working.
Will keep me now with the original values.
Do you know where to buy 2x antenna?
@Khanh An
That shouldn't be a big problem to change the M88 for the M8.
You need to change the def file and take some extra attention for the fuses bits.
If it's not working then send me a private mail with you address and i will ship some M88 here from Holland.
You can find my mail address on my website. _________________ www.evertdekker.com Bascom code vault |
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ibilzh
Joined: 11 Jul 2007 Posts: 151 Location: Germany
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Posted: Mon Feb 09, 2009 12:10 pm Post subject: |
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Evert wrote: |
Do you know where to buy 2x antenna?
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Hi Evert,
The first coils were self made. Now i buy from:
https://www.distrelec.com/ishop/StaticHTML/shared/distrelec/
Munufacturer is Codatex. (1.024 mH) Partnumber: 646684
Distrelec is also in Holland.
Another German address is:
http://www.spulen.com/shop/
This guy is a full professional, but have a look to the Web Page.
regards
Gerhard |
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sato
Joined: 07 Apr 2007 Posts: 107
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Posted: Mon Feb 09, 2009 1:38 pm Post subject: |
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Hello
What is the recommended coil, or value on the page:
http://www.spulen.com/shop/
Thanks
Kind regards
Sato |
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ibilzh
Joined: 11 Jul 2007 Posts: 151 Location: Germany
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Posted: Mon Feb 09, 2009 2:19 pm Post subject: |
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Hi,
This following link to the coil should be the right one.
http://www.spulen.com/shop/product_info.php?products_id=979
I use the coils from Distrelec, but it seems to be the same in diameter
and value (1 mH).
I do not know what kind of coil is shipped with the MCS kit. I got a test
kit without coil. There was no difference in distance between coil and
key fob with coils from 400yH up to 1mH.
The diameter of round about 15 mm for the coil was best for cards
and key fobs. I use also this 1mH coil for the dooropener from my
HomePage, and it works well since june last year.
Gerhard |
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sato
Joined: 07 Apr 2007 Posts: 107
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Posted: Mon Feb 09, 2009 4:46 pm Post subject: |
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Hello again
I want put the Atmel controller in another pcb than a em4095 chip
The question is: How long "distance" can be the wires: DEMOD, SHD and MOD
Thanks
Kind regards
Sato |
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khanh_an111
Joined: 25 Dec 2008 Posts: 15 Location: VietNam
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Posted: Mon Feb 09, 2009 5:52 pm Post subject: |
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Hello Evert ,
Thanks for your answer.
I can replace mega88 by mega8 in EM4095 KIT.
First: M88def.dat --> M8def.dat
Second: $crystal = 8000000 --> $crystal = 2000000
I don't know why we must change $crystal = 2000000
Could you tell me?
Thank you very much.
Khanh An. |
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ibilzh
Joined: 11 Jul 2007 Posts: 151 Location: Germany
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Posted: Mon Feb 09, 2009 7:08 pm Post subject: |
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Hello,
sato wrote: | Hello again
I want put the Atmel controller in another pcb than a em4095 chip
The question is: How long "distance" can be the wires: DEMOD, SHD and MOD
Sato |
Never tested. A good question. A rule of thumb is guilty for antenna.
Here not longer than 1,5 meters, and the wires has to be twisted.
To your question:
SHD is not critical, it is DC voltage. MOD can be set directly
at the EM4095 to LO (read modus). The only signal of interest is DEMOD_OUT.
Because it is a demodulated output, it should not be that sensitive. If the
chip brings a "good" signal and you use shielded wires, i think you can go
up to some meters. You find a pcb of a "only EM4095" at my Homepage.
[www emagu de/testseiten/Frames.htm]RFID mit EM4095 X X
Only EM4095 and the neccessary parts. It is in pdf format.
If you need eagle docu, email me. I have at the moment no such pcb to
test it, sorry.
Gerhard |
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sato
Joined: 07 Apr 2007 Posts: 107
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Posted: Mon Feb 09, 2009 7:56 pm Post subject: |
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Hello ibilzh
If you need eagle docu, email me.
Yes, Thank you
fsantos(at)cityelectronica.com
Kind regards
Sato |
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