I am planning on using the EMX on several devices in the future and was considering using Sharp’s LQ043T1DG01 touch screen with the EMX since it has been tested by GHI and is currently used on the ChipworkX dev system.
In reading the screen’s data sheet I noticed it has 5V analog supply pins for the resistive touch. I also see in the EMX manual that the input pins are 5V tolerant. If the X_LEFT,X_RIGHT,Y_UP, and Y_DOWN signals on the screen are 5V analog would I be able to connect them directly to the EMX module or would I need to shift the levels down to 3.3V?
Digital input pins are 5v tolerant. Analog inputs all have to be 3v3 or less.
Thank you for the quick reply!
I will just have to shift the levels on X_LEFT and Y_UP from 5V to 3.3V then. Voltage divider circuit should do the trick!
The touch screen pins have no connections to 5V
So I will need to use a voltage divider on all 4 touch pins? I thought 2 pins were digital and 2 were analog (according to the pin outs). Please correct me if I’m wrong.
You do not need any divider on any pins. The touch interface pins go directly to EMX module. See FEZ Cobra schematics please.
Thank you Gus for pointing me in the correct direction. I did not consider looking at the FEZ Cobra schematics.