Interfacing hall-effect sensor to embedded CPU

[stube40]

I ended up using a wonderful circuit simulator given away free from TI, called TINA TI.

The picture below shows the circuit. It takes an input sine wave of 2V +/- 0.28V and then outputs a sine wave a 0 - 3V (approx). The op amps are powered by the same 3.3V of the CPU/ADC and I've stuck in a 3.6V Zener diode just to be sure (not sure if I actually need that).

 

[poor mystic]

Doesn't that circuit invert the signal?

 

[stube40]

Doesn't that circuit invert the signal?

Darn!! That's the trouble with using a sine wave (or any other symmetrical wave form) to test - sometimes the obvious goes completely unnoticed.............