A Feather-based alarm clock with sound #AdafruitForums #Feather

An LCD Alarm Clock using the Adafruit Feather M0 Express with automatic correction for Daylight Saving Time and plays a short WAV file for the alarm.

Items used were:

• an Adafruit Feather M0 Express (I recommend stacking headers for the eventual attachment of wires)
• DS3231 Precision RTC FeatherWing (with stacking headers)
• CR1220 12mm Diameter – 3V Lithium Coin Cell Battery (for the RTC)
• 4-Digit 7-Segment Display FeatherWing
• Mono 2.5W Class D Audio Amplifier – PAM8302
• Mono Enclosed Speaker – 3W 4 Ohm
• 2 small pushbuttons (7 mm threaded with nuts for mounting in the case)
• 1 larger latching pushbutton (12mm – I found one with a blue 5V blue LED which works fine with 3V)
• a 1000 mAh Lithium battery to keep the clock running for a period in case of a power outage (if it loses power the alarm time would reset to the default time). See note below.

See this Adafruit Forums post for details and the code on GitHub.