# Irregular Countdown Calendar

## Arduino project to divide life into segments of irregular length

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.