Matrix Keypad for Atmel AT89C51SND1

Hi all,

I'm quite new at this, so please bare with me. I have a question regarding Atmel AT89C51SND1. For my application I need 12 different keys. As i understadn the AT89C51.. has 4 interrupt driven keys.

My guess is I can setup a 4 x 3 matrix keyboard? But, I need help in understanding how I would go about doing this in C.

Also, more specifically I need to know, if a user presses a key then how would I know which one of the 12 keys was pressed?

Thank you very much for your help.

Parents
  • so please bare with me.
    I do not think so, but I will bear with you :-)

    I have a question regarding Atmel AT89C51SND1. For my application I need 12 different keys. As i understadn the AT89C51.. has 4 interrupt driven keys.
    I do not understand, the chip does not have keys

    My guess is I can setup a 4 x 3 matrix keyboard? But, I need help in understanding how I would go about doing this in C.
    C or assembler, no difference:
    1)enable col1, any rows low? if yes, process
    2)enable col2, any rows low? if yes, process
    3)enable col3, any rows low? if yes, process
    4)again from 1

    Also, more specifically I need to know, if a user presses a key then how would I know which one of the 12 keys was pressed?
    answered above

    Erik

Reply
  • so please bare with me.
    I do not think so, but I will bear with you :-)

    I have a question regarding Atmel AT89C51SND1. For my application I need 12 different keys. As i understadn the AT89C51.. has 4 interrupt driven keys.
    I do not understand, the chip does not have keys

    My guess is I can setup a 4 x 3 matrix keyboard? But, I need help in understanding how I would go about doing this in C.
    C or assembler, no difference:
    1)enable col1, any rows low? if yes, process
    2)enable col2, any rows low? if yes, process
    3)enable col3, any rows low? if yes, process
    4)again from 1

    Also, more specifically I need to know, if a user presses a key then how would I know which one of the 12 keys was pressed?
    answered above

    Erik

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