Hi
I have been through some posts and I realised that there is a common problem interfacing 4x4 keypad with 74C922 encoder. But I couldnt find the solution using 3x4 keypad. Well becouse this keypad hast got one of the column there is a problem with the left out pin in the encoder. Can you please tell me how you make this enocder from 1-16 to 1-12 . I mean how do you deal with that extra pin ? here is what I have tried but the problem is that the numbers are 1 digit ahead. So when I presss 1 it gives zero , 2 gives 1 , 3 gives 2 , 4/5/6 are ok then 7 gives 8 , 8 gives 9 .
https://www.electro-tech-online.com/attachments/keypad-jpg.17043/
I have been through some posts and I realised that there is a common problem interfacing 4x4 keypad with 74C922 encoder. But I couldnt find the solution using 3x4 keypad. Well becouse this keypad hast got one of the column there is a problem with the left out pin in the encoder. Can you please tell me how you make this enocder from 1-16 to 1-12 . I mean how do you deal with that extra pin ? here is what I have tried but the problem is that the numbers are 1 digit ahead. So when I presss 1 it gives zero , 2 gives 1 , 3 gives 2 , 4/5/6 are ok then 7 gives 8 , 8 gives 9 .
https://www.electro-tech-online.com/attachments/keypad-jpg.17043/