I realized that my life needs a balance between regularity and irregularity.

Weeks and months provide regularity and to have an element of irregularity I have created an Arduino project to show the number of days remaining until my age in days (not years) is a prime number.

Since prime numbers appear at irregular intervals, this will divide my life into segeents of irregular length.

On irregular days I might perform irrational activities such as gambling, praying, dancing or arguing.

The number of days remaing is displayed as a Matula Tree. These characters are stored in PROGMEM.

On days where my age is a prime number (an irregular day) the screen will twinkle.

Currently my age in days is around 16000~17000 and primes appear on average every 8 days. A maximal prime gap will appear in ~10 years and will be 44 days long.

To calculate the next prime (until i'm ~100 years old) its only necessary to test numbers for divisibility by the first ~50 primes.

Components used

• Arduino Nano

• RTC DS1307 Clock module

• Mod4 Max7219 8x32LED Matrix

Libraries used

Chronos Library to calculate number of elapsed days.

Serial I/O

Connect to phone Serial USB Terminal

output: current date, days until next prime

input: new current date (RTC does not support time zones)

Planned improvements

• To resemble pendulum clock, use a sine wave to swing the number across the display rather than bouncing it.

• To make the clock seem more lively on prime days, use a sine wave to gradually increase and decrease amount of twinkles every 4 seconds.

• Use EEPROM to store led intensity level.

• Use EEPROM to store start date.

• Perhaps use the parola's font mechanism to store the numbers.

• Count down to even more irregular twin primes.

https://github.com/arnodenhond/IrregularClock