I’m a little new to hardware and electronics so please bear with me.
I’m trying to make a very simple circuit - reading from a TMP36 into the Spark Core; the TMP36 works perfectly well with an Arduino in an identical circuit.
I tried the same deal with a Spark Core but the readings were off and I set out to debug it. I stuck a multimeter in and the readings were OK again. This is what we call in the software industry a “Heisenbug”. I believe that you in the hardware world call it “voodoo”.
I removed the temperature sensor entirely from the circuit and just tested the analog pin I was reading to ground - it read 1.7v. Since it was A0 I feared interference from the antennae and moved it ( and the analogRead and pinmode) to another A1, same thing on A1 , only now A0 tests 0v like it should be.
It looks like pinmode(INPUT) is rising the voltage level on that pin to 1.7 and that interferes with my sensor; am I doing anything wrong?