bfgstew
Senior Member
Finally got round to getting this solution in its hardware state.
4 x 3 keypad and 4 x 4 keypad fitted with unique resistor matrix to give a near perfect linear voltage spread across each key press. 0.39v across each key on the 4 x 3 keypad.
0.29v across each key on the 4 x 4 keypad.
Now the hard part, to get the coding done.
Got to dig out my testing station and start to play.
A shot of the back of the 4 x 3 keypad showing the resistors in place, the 4 x 4 keypad is done in the same manner.
4 x 3 keypad and 4 x 4 keypad fitted with unique resistor matrix to give a near perfect linear voltage spread across each key press. 0.39v across each key on the 4 x 3 keypad.
0.29v across each key on the 4 x 4 keypad.
Now the hard part, to get the coding done.
Got to dig out my testing station and start to play.
A shot of the back of the 4 x 3 keypad showing the resistors in place, the 4 x 4 keypad is done in the same manner.