Hi,
I’m a little bit confuse about the analog inputs voltage of the Shield Shield.
I think that the Shield Shield objectif is the use of Arduino 5v compatible shield. But I also read at the Shield Shield web page this -> " Unlike other IO pins, the analog pins are rated at only a max of 3.3V and NOT 5.0V. Please remember NOT to exceed this voltage at anytime." !!
My question : Can I use the analog inputs pins of the Shield Shield with a 5v max input ?
Thank
Mio
A0, A1, A2 of the Arduino Uno footprint is wired up to A0, A1 and A6 on the core respectively. So you cannot exceed 3.3V on those 3 pins since they are not going through the Logic converter.
Does that make sense? 
Ok.
Just to be sure I understand : On the Shield Shield board, there are inputs for A0, A1 and A2. I can’t use these to input 5v.
Then… where can I input 5v to analog inputs on the Shield Shield board ?
Is it clear ? 
Are you trying to measure voltage? If you are measuring, you need an Analog pins and only A0, A1 and A2 on the Arduino footprint can do that but only up to 3.3V.
If you are doing something like digitalRead(), the other pins would work fine.
First, thank you for your answer and your time ! 
I use a 5v vacuum sensor (MPXV4115V) that ouput a 0 to 5v, connected to Arduino UNO analog inputs A0. What I want, is to use these sensor with the Photon. But, the analog input of the Photon allow 3.3v max.
It’s why I think I can use the Shield Shield to convert 5v output of the sensor to convert it to 3.3v to the Photon.
Mio
It’s a little overkill for a shield shield since you effectively need a logic converter like http://www.adafruit.com/products/757 but the shield shield is a good start 
@Miotang, @kennethlimcp, the shield shield does not convert Analog levels, only digital. You can use a resistor divider to change the voltage range from 0-5v to 0-3.3v or use a op-amp buffer with a gain lower than 1. I suggest the resistor approach.
Oh yes yes. Totally forgotten about that!
Thank’s everybody !
I’de find a 3.3v version of the vacuum sensor (MP3V5050VC6U)… Simpliest ! 
Mio