||Library of classes and functions to support drawing buttons on a pixel display.
||Provides a function to convert a float to a string with a specified number of digits after decimal.
||Provides a class with member function printf() that prints to a serial port.
||Provides a function to convert a number of milliseconds into a string.
||Provides same functions as SAMD wiring_analog.c with several changes to fix problems, and a function for ADC calibration.
||Support for touchscreens using the XPT2046 controller chip, cloned from PaulStoffregen's version.