2. It keeps approximately one second's worth of temperature scans stored in a buffer. This buffer is continually
refreshed. Because only the most recent second of data is held in the buffer, it is very unlikely that the unit
would store a "false peak," such as would be seen when passing the probe tip over a hot cup of coffee.
3. When the probe is positioned in the ear canal, and the scan button is pressed, the Genius collects another
buffer of data in addition to the "pre-scan buffer."
4. When determining target temperature, both buffers of data are examined for peak reading.
6.12 Sleep Mode Compared to, or Versus, Wake Mode
The Genius is able to conserve battery life by automatically placing itself into a special low-power ("sleep")
mode, whenever it is left unused for approximately one minute.
1. When in sleep mode, the +5 volt supply is disconnected from all circuitry except the CPU.
2. Installing a Probe Cover will trigger an interrupt to the CPU, putting the CPU into its normal operation
("wake") mode.
3. After "wake-up," the CPU will cause the +5 volts to become active to the rest of the circuit board. A short
time after the user completes the task of taking a temperature, the CPU will again return to sleep mode in
order to conserve power.
6.13 Sleep/Wake-Up
1. Pin 29 of the CPU is INTO. INTO is used in this application to wake-up the CPU from low-power sleep mode.
2. When the unit is residing in its base, the reed switch, SW1, is open and INTO is pulled low. If the unit has
not been used for at least one minute, the CPU is in its low-power sleep mode.
3. Removing the unit from the base causes the spring-loaded release button to drop to the "down" position.
There is a magnet bonded to the underside of the blue RELEASE button.
4. The magnet causes the contact of SW1 to close. This causes a high on INTO.
5. When a probe cover is installed, the RELEASE button is forced high, causing the contacts of SW1 to open,
thus causing a high to low transition on INTO, bringing the unit out of sleep mode.
6. If the probe cover is left in place but a temperature has still not been taken, after approximately one minute,
the CPU will again go into low-power sleep mode. In this case the INTO line is held high as described in
step 5. If this condition occurs, the menu will return to "USE NEW COVER." To reactivate the unit, the
Probe Cover must be RELEASED and reinstalled.
7. You will notice that the MODE button (SW3) is tied to INTO. The reason is as follows: If the user desires
to use the MODE button to change modes, or switch between
º
C and
º
F, he or she has no way of knowing,
nor cares, if the CPU is awake or asleep. In case the CPU is asleep, there needs to be a mechanism in
place to wake it up and cause it to perform its desired function. This is accomplished by tying the MODE
button to INTO.
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