my experience is that the onboard antenna works pretty good and it's not so easy to get a better performance with a small external antenna. Would be nice to see an image of your parasitic array based antenna (you wanted to show).
A good test condition is to put the Edison board in a metal box or cover keeping only the external antenna outside.
I'm pretty sure it isn't possible to switch between onboard and external antenna by software.
As mmi stated, the onboard antenna works very well and would be difficult to get a much better performance with an external antenna. However if you decide to keep using an external antenna and plan to disable the WiFi drivers take a look at these links that show the commands for disabling the WiFi drivers
However, I’ve not tried this procedure yet so I’m not sure it will work as expected. Give it a try and us know your results.
The antenna that I am attaching to edison is controllable directional antenna, this allows me to electronically steer the main radiation lobe to intended direction. the direction I can control in Software.
I am using this for something where I could make use of controllable antenna direction to reduce contention in the medium and hence reduce cross technology interference.
I have not been able to try hack to disable the antenna diversity. I want to keep the WiFi driver active, but disable the antenna diversity forcing one to take the external antenna.
As a quick hack, I wrapped the onboard chip antenna with aluminium foil ( see the image attached with this post). It seems to be working, I definitely see difference in signal strength as I steer the lobe of the antenna. I will play around with this more and get back to you.
Thanks for all the help :-)
thanks for your statements and the photo, this antenna is imposing.
I think i understood it right: disabling the diversity means to switch off the onboard antenna in this case. I don't know if you have done some measurements but in my opinion the internal (onboard) antenna should be switched off 'automatically' as soon as an external antenna was connected and that's a pure hardware thing. Maybe i'm wrong, but that's what i've seen in other hf equipment with additional external connectors so far.