Hardware to key in / dial in numerical inputs

Hi Arduino community!

My project is to make a count-down timer device to signal speakers that their time is up. This device would sit on, say, the speaker’s podium and will use LEDs to signal when one minute remains and when the time has run out. Additionally I could have a 7-segment display showing the minutes remaining. In the sketch I intend to take advantage of the millis() function to count down the time from reset. What is needed is a way to “key in” the time interval to be counted down. Ideally, this would not require connecting to a laptop via USB cable (although that would be easy to do). It would be better to have a small input device on the device itself to enter the time. I think that a rotary selector switch would work for this, but it would limit the number of possible time intervals that could be chosen. Is there a small keypad device for keying in numbers? What would you recommend?

Use with the <Keypad.h> library.

Small keypad!
Thanks very much!

Nah nah nah nah...

Use this! :wink:


with this face plate:


This video is using a different style of the panel but works exactly the same way, just different keypad layouts:

Thanks !

Just today I noticed this...

a digital keypad but only 4 digits. Very compact.

Yes, these are the same as 4 push buttons. Notice the 5 silver stripes inside the ribbon cable and connector? Four out of 5 come from the buttons and the fifth is the common wire that the buttons connect to, when depressed. If you want, you may connect this very keypad to a phi-panel LCD backpack. The full 4*4 keypad is just the same width but four times as tall.