Differential input (whetstone bridge) to single ended output

[Glion]

I have a whetstone bridge that can output both negative and positive values. I want to interface this to a microcontrollers ADC that only takes a single ended input 0-3.3v

How can I convert an input (-1v to +1v) to 0-3.3v output?

I've looked at instrumentation amp although i would prefer the use of op amps that don't require a negative rail and i'd need to add a DC offset so 0v = 1.65v at the input to the ADC.

[Kleinstein]

An instrumentation amplifier circuit (seprate OP-amps or a ready made chip) is a good way. For the zero shift, just have the reference point at 1.6 V.
With only a gain of about 1.6 the common mode range may be an issue and it may not be worth to use the full 3 OP-amp circuit.

Depending in the use, one could also have only a half bridge and have the 2nd half already as part of the amplifier.

[David Hess]

An instrumentation amplifier is the most common way, and the reference input to the instrumentation amplifier can be lifted to 1.6 volts to offset its output by 1.6 volts and allow negative outputs, but if you do this do not forget that the reference input does not usually have a high input impedance so buffering may be required.

Check out Linear Technology application note 43 - Bridge Circuits for a discussion of the various options.  The last one shown in figure 4 on page 4 is one of the more interesting ones, and uses 2 operational amplifiers instead of an instrumentation amplifier.

[wasedadoc]

BTW the gentleman's name was Wheatstone. https://en.wikipedia.org/wiki/Charles_Wheatstone