4-line_resistance_touch_screen.txt

- Hot to get X coordinates.
Y(+)          Y(-)          X(+)          X(-)
INPUT         INPUT         OUTPUT(HIGH)  OUTPUT(LOW)
Read the analog value twice from Y(+).
X=valueY(+)[0]+valueY(+)[1]

- How to get Y coordinates.
Y(+)          Y(-)          X(+)          X(-)
OUTPUT(HIGH)  OUTPUT(LOW)   INPUT         INPUT
Read the analog value twice from X(-).
Y=valueX(-)[0]+valueX(-)[1]

- How to get Z value.
Y(+)          Y(-)          X(+)          X(-)
INTPU         OUTPUT(HIGH)  OUTPUT(LOW)   INPUT
Read the analog value from Y(+).
Read the analog value from X(-).
Z=ABS(valueY(+)-valueX(-))