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### Topic: Numeric keypad to HH:MM:SS & millis (Read 896 times)previous topic - next topic

#### polepole

##### Feb 06, 2011, 04:22 am
I'd like to use a numeric keypad to have the user input a time (in HH:MM:SS format), and then be able to set a timer based on that input. The problem is that the user, if they want to enter 1m30s, won't be hitting 0-0-0-1-3-0. They'll just hit 1-3-0.

(to summarize: when user hits 1, display will show: 00:00:01. When they hit 3, it'll show: 00:00:13. When they hit 0, it'll show: 00:01:30.)

So how do I transpose the input into something usable? I can figure out how to display the input on the screen by sliding each number left one after a keypress, I just can't figure out how to get the corresponding millis out of it.

I've thought about dropping each keypress into it's own variable as there are only 6 total (keypress1 = 1, etc.), but I still can't figure out how to manipulate the numbers.

Thoughts?

#1
##### Feb 06, 2011, 04:35 am
What is your plan to determine when time entry is complete?
Millis (for counting down?) can then be determined by simple math:
tens_hours + ones_hours x 60 minutes/hour x 60 seconds/minute x 1000 mS/Sec =  hours_milliseconds
tens_minutes + ones_minutes x 60 seconds/minute x 1000 mS/Sec  = minutes_milliseconds
tens_seconds + one_seconds x 1000 mS/Sec  = seconds_milliseconds
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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