OPERATING INSTRUCTIONS FOR THE KENTUCKY DEPARTMENT FOR THE BLIND BRAILLE DIGITAL CLOCK CALENDAR December 3, 1992 GENERAL DESCRIPTION The Braille Digital Clock Calendar described below was designed by the Kentucky Department for the Blind. It displays the time or date on a six cell refreshable braille display. An audible alarm can be set to sound at any second within a 24 hour day. The calendar automatically adjusts for daylight savings time and leap year. A coax power jack is provided to connect the AC/DC wall transformer required to power the braille display. The power supply output should be rated at 12 VDC, 500 ma, center post positive. A power switch turns on the braille display and enables the four user pushbuttons. The internal clock runs continuously under battery power regardless of the on/off switch position or presence of the AC/DC transformer. Battery power is built into the clock chip and is rated at 10 years life expectancy. Accuracy is rated at plus or minus one minute per month or better. The unit is housed in a rugged ABS plastic enclosure measuring approximately 7" x 5" x 1.5". The total parts cost of this device (not including labor) is approximately $600. (And that's without the gold plated wristband). The Tiflotel six cell piezoelectric refreshable braille display constitutes about 75% of the parts cost. To locate the user controls, position the device with the braille display at the lower right corner of the top surface. The on/off switch will be on the left side. The power jack will be on the rear side. The four user pushbuttons will be in a horizontal row on the left half of the top surface. They are labeled from left to right with the braille characters M, F, S, C. This corresponds to MODE, FUNCTION, SELECT, and CHANGE. These pushbuttons are used to control the device. Unless noted otherwise, all references to pushbutton depressions are intended to mean press and then release that button by itself. Immediately after powering on, the braille display will show the current time incrementing each second. THE MODE SWITCH The MODE switch selects one of two modes, View or Set. To see which mode is currently active, press and hold the MODE switch. The braille display will read either View or Set. The default mode after power up is View. VIEW MODE means you can only view items with no danger of accidentally changing any item. SET MODE means you can set various items using the other pushbuttons described later. To change from one mode to the other, press and release the CHANGE button while holding down the MODE button. The braille display will alternately read View and Set. Requiring such a deliberate action to get from VIEW to SET mode ensures that clock values will never be accidentally changed by inadvertent switch depressesions. The MODE switch is also used to silence a sounding alarm described later. THE FUNCTION SWITCH The FUNCTION switch selects one of three different functions, Time, Alarm, or Date. To see which function is currently active, press and hold the FUNCTION switch. The braille display will read either Time, Alarm, or Date. The default FUNCTION after power up is Time. To change from one FUNCTION to another, press and release the CHANGE button while holding down the FUNCTION button. The braille display will alternately read Time, Alarm, and Date. Time function means that the current time is displayed as six digits. The leftmost two digits are hours, the middle two digits are minutes, and the rightmost two digits are seconds. Of course, one or more cells will automatically change each second because time marches on. Alarm function means the current alarm setting is displayed as six digits. The format is the same as the time function. Date function means that the current date is displayed as six digits. The leftmost two digits are month, the middle two digits are day of month, and the rightmost two digits are year. These three functions (time, alarm, and date) may be viewed or set depending on the currently selected MODE. THE SELECT SWITCH The SELECT switch selects various items for setting or viewing. It works differently in SET MODE versus VIEW MODE. While in VIEW mode each press of the SELECT button displays one at a time, the following items: current function (that is, time, date, or alarm), AM/PM status, alarm on/off status, and weekday. You cannot CHANGE the value of these items while in VIEW mode. While in SET mode, the SELECT button works a little differently. Each depression of the SELECT switch will select the next braille cell to the right for setting. The cell currently selected is indicated by raised dots 7 and 8. If you want to change the value of the cell currently selected, each depression of the CHANGE button will increment that cell's value by one. Keep pressing CHANGE until the digit becomes what you want. Then press SELECT to move to the next digit to the right. In this way, all six cells may be set, one at a time, to the desired digits for time, date, or alarm. There is one exeception to the above procedure. If the rightmost digit is selected while in SET TIME mode, then pressing the CHANGE button will force that digit to be zero rather than incrementing it. This facilitates setting the clock to the exact second. Simply set the other five digits first then SELECT the unit seconds digit (rightmost cell). Press CHANGE at the exact instant your reference timepiece reaches zero in the unit seconds column (which of course happens every ten seconds). There are a few more items to SET in addition to the six digits. While setting the time, if the rightmost digit is already selected and the SELECT button is pressed again, the display will show either AM or PM. Press the CHANGE button to toggle between AM and PM. Press SELECT again and the display will show either ALM ON or ALMOFF indicating the alarm status. Press CHANGE to toggle between ALM ON and ALMOFF. Press SELECT again and the display will show one of the seven weekdays. Press CHANGE repeatedly to step through all seven weekdays. Pressing SELECT one more time will take you back to the starting place, that is, the leftmost braille digit (indicated by dots 7 and 8 raised on cell 1). You may go through any or all of the SELECT items again as necessary until they are all set the way you want them. When setting the alarm, the weekday choices are skipped. If the alarm is turned on, the clock will emit a continuous high pitched tone each day when clock time matches the previously set alarm time. Be sure to correctly set alarm am/pm setting also. (Alarm on/off can also be set from within the set time function). To silence a sounding alarm, simply press the MODE switch. When setting the date, the weekday, am/pm, and alarm on/off choices are skipped. THE CHANGE SWITCH The CHANGE switch has already been described in the preceding discussion of the other switches. In summary, it is used in SET mode to change the various item values of time, alarm, and date. It is also used to change MODES (SET or VIEW) and to change FUNCTIONS (TIME, ALARM, or DATE). FURTHER INFORMATION To express comments or obtain further technical information on the Braille Digital Clock Calendar such as schematics or source code listing, contact the Kentucky Department for the Blind. Wayne D. Thompson Electrical Engineer Kentucky Department for the Blind P.O. Box 757 209 St. Clair Street Frankfort, Kentucky 40601 U.S.A. Phone 502-564-4754 or 800-321-6668 FAX 502-564-2951