his clock timer uses a PIC16F628 microcontroller to display 3 and 1/2 digit time and control an external load. The clock includes a calendar with leap year and optional daylight savings adjustments. The timer output can be set from 1 to 59 minutes and manually switched on and off. The clock also has a correction feature that allows an additional second to be added every so many hours to compensate for a slightly slow running oscillator. The oscillator uses a common 32.768 KHz watch crystal and the frequency can be adjusted slightly with the 24pF capacitor on the right side of the crystal. There are 7 displays that advance each time the 'D' switch is toggled. To make adjustments, set the RA5 switch to the "B" position and then toggle the E and F switches to advance the data in the hours or minutes digits. Then toggle the "D" switch to move to the next data. After the 7th display, it will go back to the top and display the current time. Or, just press the tim...