Dmitry Dzhafarkhanov

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10 years, 1 month ago.

Doesnt work any keypad programm on FRDM-K22F

for example http://developer.mbed.org/users/yoonghm/code/keypad/ or http://developer.mbed.org/users/DimiterK/code/keypad/

Question relating to:

Last updated: 30 Jun 2020
The FRDM-K22F is an ultra-low-cost development platform for Kinetis K Series K2x (K22F) MCUs built on ARM® Cortex™-M4 processor. Features include easy access to MCU I/O, battery-ready, low-power operation, a …

1 Answer

Erik -
10 years ago.

Can you give more details? Does it not compile? Does it give a runtime error? (Red LED blinking and mesage on serial terminal). Does it not find any keystrokes? Did you try other pins?

I use http://developer.mbed.org/users/DimiterK/code/keypad/ on LPC 1768 and it work well but on FRDM-K22F it not find any keystrokes. Tryed change other pins and no result.

posted by Dmitry Dzhafarkhanov 15 Dec 2014

That library might need external pull downs, since I don't see pull resistors enabled in the code.

posted by Erik - 15 Dec 2014

Why it worked on LPC1768 without pull downs? Could you please describe can I should connect keypad to MCU or modify code.

posted by Dmitry Dzhafarkhanov 19 Dec 2014

That I wonder too. But problem is that I don't have a keypad. I might check it later, but no guarantees since I can't really test it.

posted by Erik - 19 Dec 2014