If you want something more complicated than a rectangular black project box from RadioShack, you’ll need to either have something custom made, or work backwards – start with your enclosure, and design the system around it.
The Cellular module requires CTS/RTS support (I believe), so you’ll need a fully-endowed serial port (something labeled “K”) – I don’t believe Cobra II has one broken out as a Gadgeteer socket, so I don’t think that’s going to work out for you.
A warning: I can tell you right now that you’re not going to get very good battery life from your system. One of my main criticisms of the stuff that GHI sells is that power is always an afterthought with these products – both in terms of hardware and software.
In terms of hardware: highly inefficient linear regulators are used in the worst possible places: the 3.3V system rail (which can pull an amp of current with multiple modules attached) is regulated down from 5V – assuming 1A of current draw, that’s more than 1.5W of power thrown away due to heat right there. Even though the cellular radio module can use up to 2A of current, they still use a linear regulator. Under heavy load, that thing is throwing away almost three and a half watts of power.
In terms of software: NETMF provides the ability to put the processor into a low-power state; once there, the processor can be set to wake up on several different interrupts.
That’s what NETMF provides, but many of GHI’s products only implement a limited set of that functionality – if any at all. For example, the FEZ Cerberus has basically no low-power support built-in. And as for the other devices, if you want anything fancier than a wake-up pin, you’re probably going to have to do some native code hacking, as I’ve found waking up from timers and other stuff doesn’t seem to work reliably.
The power management is so bad that a lot of designs use a sidecar 8-bit MCU to handle the power management of the system, and wake up the main processor when necessary.
Food for thought.
