Simple Clock PCBs

January 2020   Bianchini-Love

Project Documents

After completing our Simple Clock project, which housed four breadboards full of clock components, we decided to make a PCB version. This version has all of the same components and capabilities of Simple Clock, all in a much smaller form factor that we designed to comfortably sit on a surface.

Overview

This clock is very similar to the breadboarded Simple Clock project, which has nearly identical circuitry and firmware.  The PCB version of this clock is meant to sit on a desk or a shelf, though may be mounted in other ways using the threaded insert that protrudes from the back of the PCB.  The clock provides two different brightness modes: manual brightness and auto brightness.  In manual brightness mode, the brightness of the display is adjusted using a potentiometer, and will remain at that brightness until adjusted by the user.  In auto brightness mode, the brightness of the display will change depending on the ambient light in the environment.  In this mode, the potentiometer should be set to approximately 8 o'clock.  Time is set using a single push button, which when held, will speed up the clock.  If the set button is held for a prolonged period of time, the clock will increment even faster.  When the desired time is displayed, the set time button may be released, and the clock will resume keeping time at a normal pace.

Figure 1:  Simple Clock PCB

Construction

Since we already had a baseline schematic for this clock from our Simple Clock project, getting our PCBs made involved making minor schematic adjustments and laying out the components.  Construction involved a lot of soldering, but the results were worth it.  You can find the gerber files for the PCB under "Project Documents" as SIMPLE_CLOCK.zip.

Figure 2:  The top layer of the PCB.