Hi there,
According what you need, can you provide your sensor link?
And about the I2C or analog sensor, the kid only supply 2 jack for our Grove product.
As I said jump wire out of the ATmega is cheap way for you.
More information you can view ATmega datasheet.
But need to remind you if you plug too many sensor on it, you should think about the code and the speed of chip, is it fast enough for you project or not?
The other sensor we are not sure how it work. So better you can someone where you bought from.
Any we are not support software. The code should solve by yourself.