TI-84 Plus CE:
Stopwatch and Countdown Timer
A clock in the TI-84 Plus?
It is common knowledge that the TI-84 Plus allows you to
set the time and date. What may not be
so common is that the TI-84 Plus has two functions that you can use to time
projects.
startTmr: starts
the TI-84’s timer. A time code, in a form of a real number, will be returned. For example, 476286143. For
future calculations, store the result in a variable.
checkTmr(time code):
Uses the TI-84’s internal clock to determine how many seconds passed
since the given time code.
For example:
startTmr → T
checkTmr(T)
These commands are only found in the Catalog ([2nd]
[ 0 ]).
Here are two basic programs that use these functions:
basic stopwatch (STOPWTCH) and countdown timer (TIMER).
STOPWTCH:
Stopwatch for one event
TIMER: Count down
timer from a given number of seconds, up to 999,999 seconds (277.7775 hours or
just over 11 ½ days).
TI-84 Plus CE Program STOPWTCH
ClrHome
startTmr→T
While 1
getKey→K
Output(1,1,"TIMER")
Output(2,1,"PRESS ENTER TO STOP")
While K=0
getKey→K
Output(3,1,checkTmr(T))
End
If K=105
Then
checkTmr(T)→S
Output(4,1,"SECONDS:")
Output(5,1,S)
Stop
End
End
TI-84 Plus CE: TIMER
Input "NO. SECONDS:",N
startTmr→T
ClrHome
While checkTmr(T)≠N
N-checkTmr(T)→R
Output(3,1,"000000")
Output(3,7-iPart(log(R)),R)
End
Output(3,7,"0")
Output(5,1,"TIME UP")
Note: I tried several methods to display the timer while the seconds are counting down. It wasn't enough just have Output(3,1,R) because after 10 seconds, the display would read: 10, 19, 18... Having ClrHome before Output(3,1,R) would make the time flicker too much.
Pretty basic. This should work with any version of the
TI-84 Plus since they have an internal clock.
The TI-83 and the TI-83 Plus do not internal clocks.
P.S. Any one purchased the white or gold limited edition TI-84 Plus CE yet? I'm thinking about getting a gold one.
Eddie
This blog is property of Edward Shore, 2016.