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Pietermaritzburg, S.A.
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I have looked for info on how to add an external antenna to the Arduino WiFi shield, but haven't found much. The one post spoke briefly about it, but not enough info for me to feel comfortable to do it.

http://forum.arduino.cc/index.php?topic=127665.0

I previously used the DFRobot wifi shield, and these had a connector on them to which I was able to attach a 2.4GHz with SMA antenna.
I now have a few of these available as I no longer use the DFRobot version.

Could anyone advise if this is possible, and how exactly I could do it?

The reason I want to do this is because the Arduino board & shield are mounted inside a metal enclosure, and I want to put the external antenna (with a magnetic base) on the outside, The metal enclosure is the problem, however if possible I don't want to have to mount the Arduino + shield on the outside of this box.
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There are pads next to the ICSP header for connecting an BNC connector for antenna, labeled X4 on the schematic.
Not sure  - have to remove chip antenna X1 to avoid interfence?
http://it.mouser.com/ProductDetail/Murata-Electronics/LDA312G7313F-237/?qs=BpFtYU5tmps/B22Q9sycsQ==
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Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Pietermaritzburg, S.A.
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Thank you for the quick reply.

So the little green component with the 2 sodler tabs on either side is the on-board antenna, I would have to somehow remove it.
The pads you mention next to the ICSP header are the pads either side of the little circle that the on-board antenna seems to be connected to?
Unfortunately I can't relate the schematic (where I found X1 & X4) to the actual WiFi board, are the 2 tabs where I must put the external antenna onto, or are the 2 tabs a common point, and where the circle on the board is, that is the other connection?

Looking at a different WiFi board, the threaded part of the connector is soldered in 2 places (although still common), and the centre pin soldered to a second point. Excuse me if what I'm explaining is incorrect, I don't know much about antennas, and why it needs 2 connections confuses me too.  smiley-grin
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Pietermaritzburg, S.A.
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This is the antenna I want to connect to it : Part No. BY-2400-03

http://www.otto.co.za/index.php?page=products&c=6&category=wifi-lan-antennas-2.4ghz
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The outer 2 rectangles are Gnd, the inner circle is the signal part of the antenna.
I think the pads are intended for some kind of BNC connector that the antenna cable would plug onto.
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Arduino for Teens available at Amazon.com.

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Thank you, before I try removing the on-board antenna, I'm going to try connect an external antenna. I understand that it might cause interference, but maybe I get lucky and it doesn't.
I will be sure to post my results.
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I am interested in this topic as well. Too bad the forum won't provide bookmark and I just have to reply in order to keep it in my list of posts.

CrossRoads,

Do you mean a square surface mount socket like this kind may replace the green antenna?

http://www.giga-concept.fr/catalog/components/coaxial_connectors/miniature_coaxial_connectors/
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I believe so liudr.
Have to check sizing: open the Wifi .brd file and take some measurements.
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Arduino for Teens available at Amazon.com.

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Thanks CrossRoads! It's good to know there is such option. I am working on a project that will likely have one wifi hotspot and several arduinos with wifi shields. I could give this a try.
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I got cold feet on making the changes to the board as I only have one which I need and can't chance messing up, however this document pertains to the possibility of adding a connector for an external antenna :

http://www.asegermany.com/ase_MC_Ultra-Miniature%20Coaxial.pdf

As per the schematic, it uses the MC-921 connector
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