Is there anyone hacking a different firmware which is not for Arduino and could-use? For me this design is limiting too much and i’d like to see some simple basic firmware where i have more control over the hardware.
At least i see lots of people complaining about the stability with wireless connectivity and could-connection.
And since the NSA-Stuff we all know that using a could is not cool 
I think the NSA has better things to do than snoop your local WiFi or monitor everything on Amazon ECS… The fact is, if they want to spy on you then they’ll find a way. The only way to avoid this would literally be living in a cave. (Osama Bin Laden is a good example of this. He lived in caves for years and we could never quite get to him, but as soon as he went all “Real Housewives of Pakistan” and moved into that house, boom, gone.) ;-D
Seriously though, right now you can download all the libraries and use a local build environment to cross compile and upload via USB with dfu-util. If you go this route you could easily add advanced functionality with real libraries that can work outside of the normal void setup() / void loop() sketches.
You can also just treat it like a normal STM32 and use any compiler and/or libraries that support the STM32/ARM Cortex-M (e.g., GCC, CLANG, IAR, mikroC/Basic/Pascal). You’d need to either adapt the Spark CC3000 drivers or grab the TI Reference drivers (designed for their Tiva C line of ARM Cortex-M chips) and make your own standalone driver.
Another thing to keep in mind is that the Spark Team is going to be opening up the entire Spark Cloud, which will allow you to run your own local/remote instance of it, so you don’t have to rely on Spark. 
That said, if you don’t need a Small, Always-On, Arduino Compatible and Cloud Connected Microcontroller, the Spark Core might not be for you. You could get an MSP430F5529 Launchpad (or) Tiva C Launchpad plus a CC3000 BoosterPack and use FreeRTOS + MSPWare with CCS6, all for about the same price as the Spark Core.
(I’m not trying to push sales away from Spark or anything, I just think you should always use the right tool for the right job.)
Hi @moeter,
You can code everything down to the bare metal if you like, instructions on setting up a build environment are here: https://github.com/spark/core-firmware
We’re also working on a local open source cloud so your session doesn’t need to go out over the internet if you don’t want. You also have the ability to generate your own cryptographic keys for your core if you feel like it.
Thanks,
David