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11 years, 8 months ago.
Keypad 4x4 some keys not working, Software fault
Hello there,
I am trying to create a project using the MBED 1768 and I am using a 4x4 keypad for the user data input. I am new to the keypad library and not a professional user of #C but i was wondering if you can give me a hand.
I connected the keypad without any extra components, ie resistors, and I am using the interrupt triggered keypad library. The problem that I have is that keys 3,6,9,8,0,D are not working! At first I thought it was a hardware problem so i purchased a different keypad from a different manufacturer but still the same keys are not providing an input.
I tried shorting the pins with a wire, ie Pin 8 and Pin 5 to get a '3' and it is working, I am displaying on the LCD the number 3. When pressing the specific keys I do not get an output of around 3.3V on the pins as I do with other keys and when checked for resistance is an open circuit! I checked the program with 3 different keypads and I ve got the same problem with all 3 of them!
I tried changing the debounce time but still no positive effect!
Did anyone have the same problem? Does anyone have any advise to give me?
Any help would be greatly appreciated!
Thank you very much for your time!!
Problem solved! Wrong datasheet provided by manufacturer. Keypad broken apart and got the correct pin configuration. Input and output pins re-initialised and it is working as expected.
posted by Georgios Vasou 19 Mar 2013