I heard some where a while back that you get a strain gauge amplifier (instrumentation amp) that can also supply the strain gauge with an excitation voltage. Is this true? How good does it work?
We used to use an AD620 and currently we have an AD8221 in our new design, unless we can find this "one-chip" solution.
If not, any suggestions for a method for an accurate (not super precise) excitation voltage?
We have AD8290 which you can use for a low power strain gauges. It has an integrated excitation current that can provide 300 uA to 1300 uA range suitable for low power gauges. Some sigma delta ADCs has also single chip solution that comes with an integrated PGA which you might want to consider like AD7190 as shown on CN-0102.
AD8290 is a fix gain (G=50) sensor amplifier other than this, we can offer AD8221 or AD8421 for lower noise or AD8422 for low power although it doesn't come with this excitation sources.
Hopes it helps.