MLX90720 Datasheet, PDF (5/12 Pages) List of Unclassifed Manufacturers – One Button Timer

MLX90720
One Button Timer
TBT with restore memory
The second button (button 2) has two functions: it is
used to restore the last programmed time and is
used to decrement the timer value in programming
mode. Whatever mode the chip is in, when button 2
is pressed (long press in programming mode and
short press in the other modes) and button 1 is not
pressed, the last programmed time is restored (not
blinking) and the chip enters programming mode.
Wake up:
Pressing button 1 or button 2 always wakes up the
chip within two seconds (debouncing + startup
oscillator):
If the chip is activated by pressing button 1, the time
value 00 is displayed (not blinking).
If the chip is activated by pressing button 2, the last
programmed time is restored (not blinking)
The chip always enters programming mode.
Programming mode:
In this mode the last programmed time can be
displayed by pressing button 2.
Programming of the timer is done with button 1 and
button 2.
When button 2 is not pressed:
If button 1 is pressed and released (short press), the
single increment mode is selected, in which the time
value is incremented with one least significant digit
(LSD), i.e. with one minute.
If button 1 is pressed for more than 1 second, the
chip enters the fast increment mode, increasing the
value of the programmed time with a speed of 4 LSD
per second. The timer can switch back and forth
between single and fast increment mode.
While button 1 is pressed:
If button 2 is pressed for a short time, the chip enters
decrement mode. Each short press on button 2
decrements the time with 1 LSD, and when pressing
for more then 2 seconds, the chip enters fast
decrement mode, decrementing the programmed
time with a speed of 4 LSD per second.
If button 2 is not pressed for more then 1 second, the
chip enters increment mode again.
If button 1 is released and button 2 still pressed, the
last programmed time is restored.
In increment mode, when exceeding 99 minutes the
timer jumps to 00 minutes.
In decrement mode, when passing 00 minutes the
timer jumps to 99 minutes.
If no button is pressed for more than 2 seconds and
the display is not at 00 the chip enters countdown
mode.
When 00 is displayed and no button has been
pressed for more than 45 sec. the chip enters
power down mode.
Countdown mode:
In this mode the last programmed time can be
restored by pressing button 2 for more than 1
second.
The countdown mode is indicated with a blinking
display with a cycle of one second (0.5 sec's on,
0.5 sec's off). The countdown of the last minute is
displayed in seconds: 1min, 59s, 58s,...0s.
At the end of the countdown, the chip enters
ringing mode.
Reset is possible during the countdown by
pressing button 1 or button 2 for more than 1
second. If a reset is generated with button 1, the
value 00 is displayed and the chip enters
programming mode. If a reset is generated with
button 2, the restore function is activated and
programming mode is entered.
Ringing mode:
In this mode the last programmed time can be
restored by pressing button 2.
At the end of the countdown, a ringing is produced,
which warns the user :
- 10 groups of 3 sounds = 10 sec.
- a delay of 20 seconds
- 10 groups of 3 sounds
The second group of sounds starts 30 seconds
after the end of countdown. In this way a time with
a resolution of 30 seconds can be achieved.
At the end of the cycle, the timer value 00 is
returned and programming mode is entered.
During the ringing mode, the display continues to
blink. This mode can be interrupted by pressing
button1. In this case the value 00 is displayed (not
blinking) and the chip enters programming mode.
Ringing mode can also be interrupted by pressing
button 2. In this case the last programmed time is
restored and programming mode is entered.
Power down mode:
When the chip enters this mode the oscillator and
the display are disabled, and current consumption
is minimized.
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RePvaYg.Xe 5
22/Aug/98 Rev 1.0 30P/aNgoev5/00