Hi,
Noob question from a complete beginner - is there a way to use the 1Shield for arduino with the spark core?
I see the spark core has an optional arduino shield add on to convert the footprint and pins of your Spark Core into that of an Arduino. How would this work in practice? Would the 1Shield connect directly to this shield/board or would you have to wire the two together?
I realise this is related to both 1shield and spark but thought I would ask here first.
Thanks,
D
Their website is like not really accessible and i’m not able to find the pinouts used by the 1Shield .
So you can either use the Shield shield for simplicity but can also manually jump wires to connect direct from the 
core to the 1Shield .
Just take note that the Shield shield doesn’t not follow exactly the pinouts of an Arduino and some pins are not available. (http://docs.spark.io/#/shields)
Okydoky, I was looking at their kickstarter site to get a better understanding of how this thing works. First, the 1Shield uses Firmata to read the arduino pins. Since the Spark Shield-Shield does not provide a perfect mapping of the arduino pins, there is a potential problem since I am not sure how their phone apps would react. As kennethlimcp pointed out, you can use jumpers to configure your own pin mapping but it will never match exactly since the Spark does not have as many pins as an arduino.
For their arduino library to work, they communicate via the serial port on pins 0 & 1 which ARE connected to the correct pins on the Spark. So their library would need to be ported but it could work.
There are risks but hey, got have fun right! 