I want to add the 3DTouch sensor and so need to build and upload an updated firmware image.
I am very conversent with Arduinos and the IDE under WIN 7.
However, I seem to be spinning in circles finding the right firmware and build environment.
Can some kind soul please tell me :
1. What firmware archive I should use ?
2. and which version of the Arduino IDE to build it under ?
I have Arduino 1.0.1 and 1.8.10 but all possible combinations seem to give errors at build time

Any help is much appreciated.
David