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Modern and New and Easier Example of Locker With Arduino Matrix Keypad 4x4

Another example of using a LCD keypad matrix 4x4 with an I2C circuit.

This matrix keypad is made of 16 push buttons and with I2c communication, you just need 2 pins to manage it: SDA (A4 on arduino board) and SCL (A5 on arduino board).

I used a PCF8574A 16 DIP I/O I2c circuit the small schematic is given above. The address of this kind of components is 0x3C in my example (A0=0, A1=0, A2=1).”

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