Whenever digital handshake or software is involved I always run into a brick wall. I am looking ahead at the Adafruit parts and what looks like the driver is very long and it has to find includes.   I don't know where to get the includes unless they are already in the Arduino C library.

This is what I figured is the driver:
https://github.com/adafruit/Adafruit_ADS1X15/blob/master/Adafruit_ADS1015.cpp

I see 300 lines of code, some looks like it repeats.  I have no idea how to handle this stuff or what each line does.

Thanks for the help.

Good find!  Many thanks especially for the speedy reply.  I am considering the option that I called a failure but I think the parts you identified are a better way. I am afraid of digital interfacing mostly because I once saw hand written PIC16F88 code for it and it was done for me.   I spent a long time fighting assembly language and it is not over yet. One day I will have to face it.
 
Is there a way to question folks on some 100 year old magnetic amplifier technology?

I am new to this forum but not to op-amps.  I would like to know if the Arduino Mega can do what the INA125 (instrumentation amplifier) does almost (but making a digital output number) sitting at the null point of a wheatstone bridge.  I imagine using the analogReference command and some kind of differential input (hopefully the reference input is an internal voltage) and using one of the rumored gains (5, 10, 20, 40).
I do not see any commands for this in the C language reference.  This is unfortunate because I am using the easily understood C that the Mega uses and so far everything is written in C.

My present input is a 1K resistor in series with a 1K ohm RTD (yes it is not the 100 ohm standard RTD) generating 2.5Vdc. If I have to make the other side of the wheatstone bridge with real resistors and use an op-amp to increase the gain, then that will work but it is considered to be a failure.
Once again what I need is the C instruction keywords and maybe an example showing how to use them.  I am already familiar with analogRead and analogReference.  I need something additional.