Read coordinates from an XPT2046 touchscreen and displays the coordinates by
flashing the blue and orange LEDs (MSB to LSB, red LED serves as a clock).
Sounds simple enough. Yeah, right.
Mistakes made (in addition to misreading docs):
- Trying to sample in 8-bit mode. This is damned useless.
- Trying to use the BUSY signal. Pointless, better left alone.
- Not oversampling.
Connections to use: see xpt2046.h
Requires an SPI driver with SPI_USE_WAIT; SPI_USE_MUTUAL_EXCLUSION supported.
Program includes some idiot-proofing to prevent being unable to flash the board
(press user button, press reset button, release reset button, red LED lights up
to indicate idiot-proof mode).
