A portable clock with an OLED character display |
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This describes the current, third, version of this project. The first version was put into service in the fall of 2022. It worked as intended, but was little used, partly because it was clumsy to use and had to be removed from its case to set the clock using two push buttons which did not work very well. In august 2023 it failed and I balked at repairing it because the connections were so difficult to get to or trace the wiring. I decided to remodel it more neatly. The second version retained the case, front panel, platform, securing screw, battery, sensor, and display from the original. The major change was to replace the 12-position switch with an incremental encoder with an integral push-button switch. The seperate battery charger and DC-DC converter modules were replaced by a combined module. To save space, the DS3231 RTC was replaced by a DS1307 module with attached backup battery. A way to control power was now needed. It would have to be initiated by the push-button without intefering with the push-button's uses during operation, and not consume much power when off. The second version used a Picaxe micro-controller operation at a reduced clock rate of 31 KHz as an elegant solution. Unfortunately the Picaxe operated erratically and its programming connection was a nuisance to use. After many attempts with software testing this approach was abandoned in this third version with a discrete transistor circuit which was satisfactory as designed. | |
| These are the photos of the Clock. | |
These are the components which constitute the Clock, | This program has been written for this Clock.
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