From old alarm clock to Wi-Fi-controlled LED display

Index, feed.

I have been actively avoiding classic clocks for quite some time. While they might come in a variety of lovely designs, I also find them a pain to maintain: without frequent manual updates, the time they display will skew further and further from the correct time and, at best, they need to be updated twice a year to account for daylight saving time changes.

Of the models that do not run on a battery, there are different failure modes; when power returns, the clock may:

• start from the time displayed when power was cut off; or

• start from midnight, with or without a visible reset indicator (when present, this is typically blinking; or

• have kept running from a backup battery, but the backup clock may run slower or faster than in the normal operation mode, resulting in noticeable shifts except for short power failures.

For this reason, and also because I like to reduce always-on lights in my bedroom to a minimum, I have not been using an alarm clock for many years.

Still, I couldn’t get myself to throw away an otherwise perfectly fine, relatively good-looking alarm clock I had. Instead, I finally spend the time to gut it and replace its innards with an ESP8266-based LED clock.

Alarm clock build

This uses a smaller display than the previous project (16x8 LEDs instead of 32x8), and the bottom row of pixels is mostly obscured by the FM radio frequency bar. I did not bother to update the code to account for either condition; rather, I make sure to:

• send strings that fit within the horizontal limit; and
• use a shorter font than the default (3x5 pixels rather than 3x7).

www.kurokatta.org

David Haguenauer <www@kurokatta.org>
$Id: cyberpunk-alarm-clock.malblog,v 1.3 2022/08/03 22:49:44 homer Exp $