I am designing a board at the moment and want to have the ability to add modules to it.
Want to add the ability for wifi, blue tooth, zigbee and gsm
Question…i love the xbee form factor…can i get modules as above with this form factor?
I want to use modules that can work with G120 chip?
Would it be possible to get the redpine wifi module on a xbee form factor…would be a great accessory…
What other methods are available to add modules to a board design?
I think gadgeteer sockets are better for this need.
But this will be a commercial product…
The other issue you would have is that, taking the RS911 module for instance, it’s not a UART interface under the GHI library (it uses SPI) so you would effectively have a non-standard Xbee form factor if you went this way.
I think Gus is wise in his choice of staying with the Gadgeteer format. At least this way, you have a number of different pinouts to plug into and 1 socket is going to be cheaper for manufacture too 
I don’t know of a GSM module with this form factor.
As for a Gadgeteer socket based approach, this may or may not be appropriate for your product. Gadgeteer sockets are high quality connectors. Depending on who your customers are, the Gadgeteer cables might be a killer, though. We’ve seen customers who say that for them, using such cables in a final product is simply not up for discussion. No further argument accepted.
@ Cuno What do you mean killer? The sockets are too expensive? Cables in commercial product not desired? Probably no justification for this feeling…it could be not wanting to change?
using standard flat flex cables when high speed high integrity signals are required, would be my suspicion on why Gadgeteer cables would be considered not ideal. If you’re working in a harsh environment, those things would be bound to be “problems” waiting to happen
Exactly. They expect reliability problems due to “flimsy” cables.
Not sure I agree with that.
Sure, if the cable is being disturbed all the time then you would need to make the right choice. Consider that the connection on a laptop to the screen is a cable of some sort. They work well and only rarely do you get a failure and yet they are being flexed all the time as you open and close the LCD. 
Modern cameras for instance, are all flex PCB designed and reliable.
I use a flat flex cable to connect the front panel to the main PCB and never had a failure. IDC cables like the Gadgeteer are also reliable if not plugged and unplugged or stressed all the time. It’s all about the correct choice at the end of the day.
Thank you everyone…i think i will use the MikroBus or use the xbee form factor as a module interface…no reason why i cannot make this universal and introduce spi,i2c, uart and gpio
To add to this question…what if i have spi going to to xbee form factor headers…is their a way to have the spi only active on one header? I was thinking of using header pins to turn on/off connections?
True and that’s why I said the right choice has to be made as to the type of cable used.
PS… When I get time, I’ll check out the CAN issue you referred to.
Not working on the Gadgeteer cable.
@ anthonys You should know that there are commercial products that use Gadgeteer on the inside. I recently worked on one. So, you should know that you would not be the first. Unless there is a business reason to go another route, I would consider Gadgeteer the default path to follow for NETMF based modular systems.
We have been using the gadgeteer sockets on many commercial projects. Take displays for example. We make a custom boards for a commercial customer and then keep the display signals on RGB sockets. Then the customer does not need to engineer display, they just use the ones already available.
We did the same for WiFi and other modules.
GSM Modem using xbee form factor found
https://www.semiconductorstore.com/cart/pc/viewPrd.asp?idproduct=48966
or
http://www.seeedstudio.com/depot/GPRSBee-p-1581.html
Would this suffice?