|Summary:||The Programmable Timer stores an Event time list. As each
time is reached, the beeper sounds and waits to be acknowledged
by the user. A Snooze option allows the user to delay acknowledging
the event. A logging option records which event were acknowledged
and which were delayed with Snooze.
The ATmega328 is kept in sleep mode to conserve battery power.
The UI consists of two LEDs, two buttons, and a beeper. There is also a mute switch for the beeper.
|Specifications||1 MHz ATmega328PA with 3v CR2032 coin cell battery. A FTDI/USB serial interface for programming and reading back data.|
|Dimensions:||2.1" x 2.1 x 0.65"|
|Power:||3v from battery or 5v from FTDI.|
|Schematics||Programmable Timer schematic|
The Programmable Timer (PT) project is designed store a list of Event time to notify the user that
an action needs to be taken. Event times are in real time Date-Time isoformat and the PT uses a 32.768 kHz
crystal to maintain local time.
Event times are programmed through a FTDI/USB serial port. The port can also be used to set the local time, read the local time, dump the event table, dump the data log, erase the data log, and place the unit in self-check mode.
The unit is normally in Sleep mode and wakes up every eight seconds to check for an event or comm port data. An Event that is earlier than the local time will trigger a beep or tune that the user should acknowledge (A button) or delay with Snooze (S button). These action are recorded in the log maintained in non-volitile EEPROM for recovery later.
Different beep sequences or tunes that are played can be selected for the event by using the ones digit of the seconds time for the event. Therefore, all event times resolve to 10 second steps.
The FTDI/USB serial interface is 8N1 at 4800 baud without handshaking.