Learn how to connect 4x4 hex keypad with Atmega16 using interrupt and MM74C922 encoder ic. The MM74C922 ic is a 16 key encoder with output enable, button debounce and data avaliable functionalities.
The output enable is inverted pin and should be grounded for continuous data output. Data avaliable pin goes high for one cycle if new data is present on the output pins of MM74C922.
Another method not to use MM74C922 is polling the microcontroller continuusly. Polling reduces microcontroller efficiency and de
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