We are developing a shield to build a feature rich open source tracker, It will contain GSM, GPS, an I2C accelerometer, uSD card slot and a connector for a standard 3.7v LiPo battery with charge functionality.
All the components on the shield works at 3.3v so we were wondering if it make sense to design this shield for 3.3v only in order to reduce costs and power consumption, from the programming point of view it make no difference you have only to chose the right board definition in the arduino IDE.
PROS: lower cost (less components) lower power consumption (this is particularly important for a device meant to be powered from a battery) better match with modern sensors (if you want to add other functionality)
CONS: it will be only compatible with 3.3V arduino board. (I don't know if this is a real drawback, in fact an arduino PRO 3.3v costs about 20$)
What do you think about this?