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PSoC 5, 3 & 1 MCU

Anonymous
Not applicable

 I' ve been trying to write the code for a 8 by 7 keypad using polling method . The problem is that I have all the coloumns connected to 4.7K external pull up resistors. And I cant able to find out which drive mode to be set for both cols. & rows. I have tried every possible combination. Pls suggest which should be used and also pls verify my code. The project is attached below.  

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1 Solution
Bob_Marlowe
Expert II

I would suggest not to use external resistors (if that is possible), otherwise you have a voltage divider between the internal pullup resistor and the external. This will result in a voltage that is neither High nor Low.

   

Bob

   

 

   

PS: I've posted some time ago a solution for a 3x4 matrix keyboard for PSoC3 and PSoC5. Just for your understanding have a look at it (with PSoC Creator 2.0) Search for "matrix" here or in the PSoCDeveloper forum.

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Anonymous
Not applicable

 My only problem is I cannot able to make a key's  coloumn low and row high at the same time. Help me with the driving mode for the coloumn and row of the keys

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Bob_Marlowe
Expert II

I would suggest not to use external resistors (if that is possible), otherwise you have a voltage divider between the internal pullup resistor and the external. This will result in a voltage that is neither High nor Low.

   

Bob

   

 

   

PS: I've posted some time ago a solution for a 3x4 matrix keyboard for PSoC3 and PSoC5. Just for your understanding have a look at it (with PSoC Creator 2.0) Search for "matrix" here or in the PSoCDeveloper forum.

View solution in original post

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