Crosslakeguy,
I gave up on you because you keep going off on tangents.
I told you that a 4066 would work. I don't think you ever believed me.
Alec showed you how to use them. You pretty much ignored him.
I asked you
here for details. You promised to get back with them, but never did. I was going to design a circuit that requires no analog switches or relays.
I haven't used digital pots. I could figure out how to use one from the datasheet.
A digital pot can be used as a rheostat, but there are a lot of details to attend to. Low-cost units have huge resistance tolerances, like ±20-30%, and resistor tempcos of 200-300ppm/°C. You can buy low tolerance, low tempco units, but they are relatively expensive, and have peak current specs that have to be adhered to.
You can use a low-cost unit for your application in ratiometric mode, which is what they are designed for, but it would require more parts, like an op amp, a transistor, and a couple of resistors.