TCA8418: How to configure TCA8418 IC to save only "Pressed" events in the FIFO?

Chameera Wijethunga

Part Number: TCA8418

The TCA8418 key scanner IC, contains a FIFO which stores both "Pressed" and "Released" events. I want to configure it to save only the "Pressed" events. How can I do it and what are the register addresses and the values that I should set?

over 1 year ago

0 Tyler Townsend over 1 year ago

TI__Mastermind 43413 points

Hi Chameera,

The recording of the key press / release events is not configurable to just the recording of press events. The filtering between these two events would need to be done in software by throwing away the data that contains KEA[7] = 0.

Regards,

Tyler

0 Chameera Wijethunga over 1 year ago in reply to Tyler Townsend

Prodigy 10 points

Hi Tyler

Thanks a lot for your response. I have another question. Is there a way that I can clear the entire FIFO with a single register write operation? (without reading the "TCA8418_REG_KEY_EVENT_A" register)

0 Clemens Ladisch over 1 year ago in reply to Chameera Wijethunga

Guru 314120 points

Only with the /RESET pin, which would also reset the configuration.

During normal operation, you can empty the FIFO only by actually reading all events.

0 Tyler Townsend over 1 year ago in reply to Chameera Wijethunga

TI__Mastermind 43413 points

Hi Chameera,

Please let me know if Clemens response answered your question. I agree with his solution.

Regards,

Tyler

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TCA8418: How to configure TCA8418 IC to save only "Pressed" events in the FIFO?