lookslikeruck:
zarobhr:
you might want to do as suggested and use a multimeter to map out the pins (shows how in the tutorial)
i mapped mine out and this was the combination i got although the keypad is. Not all keypads that seem to be the same wiring are the same wiring123
456
789
C0Econst byte rows = 4; //four rows
const byte cols = 3; //three columns
char keys[rows][cols] = {
{'1','4','7'},
{'2','5','8'},
{'3','6','9'},
{'C','0','E'}
};
Yhap, but the mapping it's not the problem...
It seems that when I pressed keys 2, 4, 6, 8 and 0 the Arduino just doesn't recognized them.I'm not sure how the keypad works internally but I think it's based on the Voltage Divider Principle, with voltage drops between the keys that can tell wich of the key is being pressed.
Is it possible that the resistors drop less voltage than the library it's configured for?
matrix keypads do not work on voltage divider principle (it shorts the wires/pins)
think of it like a switch, when you press a key only 1 pair of the seven wires will make contact and it should be nearly a complete short, just becuase the odd numbers work and even dont doesnt mean its not a mapping problem. its very likely that it is a mapping or a wiring problem