CD74HC4067 Multiplexer Info Needed

Forum 2005-2010 (read only) Hardware Interfacing
1

Hey guys,
I have a resistive touch screen using analog pins 0-3 and then i have a blinkm using up 4 and 5. I need to add an additional potentiometer but i am out of analog inputs.

If i were to get the CD74HC4067 Multiplexer, specifically the breakout from sparkfun SparkFun Analog/Digital MUX Breakout - CD74HC4067 - BOB-09056 - SparkFun Electronics would i be able to hook the screen up to 4 of the inputs on it and the additional pot and still have 11 remaining inputs?

I read somewhere that the multiplexer reads one of the inputs at a time, that might cause a problem with the touch screen since it reads the X and Y at the same time.

:-?

2

I read somewhere that the multiplexer reads one of the inputs at a time,

Yes it does and there is no latch. You might have to end up using an external A/D to read the pot. Something simple like a resistor & capacitor where you put a logic high and time how long the cap takes to charge. (single ramp converter)