primetime

are you living on a prime numbered day of your life?

What It Does

• Tracks up to 4 people's birthdates
• Calculates the number of days each person has been alive
• Lights up their dedicated LED when that number is prime
• Each LED stays on for the entire prime day
• Includes a status LED for system health monitoring
• Automatically syncs time via NTP (Network Time Protocol)
• Reconnects to WiFi automatically if connection drops

Hardware Required

Core Components

• ESP8266 microcontroller (choose one):
  • NodeMCU v1.0
  • Wemos D1 Mini
  • Any ESP8266-based board with at least 5 available GPIO pins

LEDs & Resistors

• 5x LEDs (any color you prefer):
  • 4 for family members
  • 1 for status indicator
• 5x 220-330Ω resistors (one for each LED)
• Breadboard (or perfboard for permanent installation)
• Jumper wires

Power Supply

• Micro USB cable (for programming and power)
• USB power adapter (5V, 1A minimum) for permanent installation

🔌 Wiring Diagram

ESP8266 (NodeMCU)          Component
─────────────────          ─────────
D1 (GPIO5)  ──[220Ω]────── LED1 (Person 1) ──── GND
D2 (GPIO4)  ──[220Ω]────── LED2 (Person 2) ──── GND
D5 (GPIO14) ──[220Ω]────── LED3 (Person 3) ──── GND
D6 (GPIO12) ──[220Ω]────── LED4 (Person 4) ──── GND
D7 (GPIO13) ──[220Ω]────── LED5 (Status)   ──── GND

LED Connection Steps

1. Connect the long leg (anode) of each LED to a 220Ω resistor
2. Connect the resistor to the corresponding GPIO pin
3. Connect the short leg (cathode) of each LED to GND
4. Double-check polarity before powering on!

💻 Software Setup

Prerequisites

1. Arduino IDE (1.8.x or 2.x)

   • Download from: https://www.arduino.cc/en/software

2. ESP8266 Board Support

   • Open Arduino IDE
   • Go to File → Preferences
   • Add to "Additional Board Manager URLs":

     http://arduino.esp8266.com/stable/package_esp8266com_index.json
     

   • Go to Tools → Board → Board Manager
   • Search for "esp8266" and install "esp8266 by ESP8266 Community"

3. Required Libraries (install via Library Manager):

   • NTPClient by Fabrice Weinberg
   • TimeLib by Michael Margolis
   • ESP8266WiFi (included with ESP8266 board package)

Installing Libraries

1. Open Arduino IDE
2. Go to Sketch → Include Library → Manage Libraries
3. Search for and install:
   • "NTPClient"
   • "Time" or "TimeLib"

⚙️ Configuration

1. WiFi Settings

const char* ssid = "YOUR_WIFI_SSID";        // Your WiFi network name
const char* password = "YOUR_WIFI_PASSWORD"; // Your WiFi password

2. Timezone Configuration

const long TIMEZONE_OFFSET = -7 * 3600; // GMT-7 (Pacific Time)

Find your timezone offset:

• PST (Pacific): -8 * 3600 or -7 * 3600 (DST)
• MST (Mountain): -7 * 3600 or -6 * 3600 (DST)
• CST (Central): -6 * 3600 or -5 * 3600 (DST)
• EST (Eastern): -5 * 3600 or -4 * 3600 (DST)
• GMT/UTC: 0
• CET (Central Europe): 1 * 3600 or 2 * 3600 (DST)

Full list of UTC offsets

3. Family Member Configuration

FamilyMember family[4] = {
  {"Aba",   1990, 1, 15, D1, false, 0},  // Name, Year, Month, Day, Pin
  {"Bobo",     1992, 6, 22, D2, false, 0},
  {"Coco", 2015, 9, 8,  D5, false, 0},
  {"DeeDee",   2018, 12, 3, D6, false, 0}
};

4. LED Brightness (Optional)

const int LED_BRIGHTNESS = 40;  // 0-1023 (1023 = full brightness)

• 40 = ~4% brightness (wasy on eyes)
• 100 = ~10% brightness
• 512 = ~50% brightness
• 1023 = 100% brightness

5. Test Mode

const bool TEST_MODE = false;  // Set to true to test all LEDs

When TEST_MODE = true, the system cycles through each LED (including status LED) every second.

Uploading the Code

1. Connect your ESP8266 to your computer via USB
2. Open primetime.ino in Arduino IDE
3. Select your board:
   • Tools → Board → ESP8266 Boards → NodeMCU 1.0 (ESP-12E Module) (or your board)
4. Select the correct port:
   • Tools → Port → (select your USB port)
5. Click the Upload button (→)
6. Wait for "Done uploading" message

Testing & Debugging

Serial Monitor

1. Open Tools → Serial Monitor
2. Set baud rate to 115200
3. You should see:
   • WiFi connection status
   • Network scan results
   • Time sync confirmation
   • Current prime day status for each person
   • System status updates

Test Mode

1. Set TEST_MODE = true in the code
2. Upload the code
3. Watch each LED light up in sequence (1 second each)
4. Verify all connections are working
5. Set TEST_MODE = false and re-upload for normal operation

Status LED Indicators

• Solid ON: System operational, WiFi connected
• Blinking: WiFi disconnected, attempting to reconnect

Understanding Prime Days

A prime number is a number greater than 1 that can only be divided by 1 and itself. For example:

• 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37...

The system calculates days since birth starting from day 0 (birth date). So:

• Day 0 = Birth date (not prime)
• Day 1 = 1st day after birth (not prime)
• Day 2 = 2nd day after birth (PRIME! ✨)
• Day 3 = 3rd day after birth (PRIME! ✨)
• Day 4 = 4th day after birth (not prime)
• Day 5 = 5th day after birth (PRIME! ✨)

Expected Prime Day Frequency

As you age, prime days become rarer:

• First year: ~61 prime days
• Age 10: ~1 prime day every 5-6 days
• Age 30: ~1 prime day every 10-11 days
• Age 60: ~1 prime day every 14-15 days
• Age 90: ~1 prime day every 17-18 days

Troubleshooting

WiFi Won't Connect

• Verify SSID and password are correct (case-sensitive!)
• Check that your router supports 2.4GHz (ESP8266 doesn't support 5GHz)
• Ensure router is within range
• Check serial monitor for connection error codes

LEDs Don't Light Up

• Verify wiring and LED polarity (long leg = positive)
• Check resistor values (220-330Ω)
• Test with TEST_MODE = true
• Measure voltage with multimeter (should be ~3.3V on GPIO pins)

Wrong Time/Date

• Verify timezone offset is correct
• Check that ESP8266 can access internet (required for NTP)
• Wait a few minutes for initial time sync

Compilation Errors

• Verify all libraries are installed
• Check that ESP8266 board package is installed
• Try updating to latest library versions

Advanced Modifications

Change NTP Server

NTPClient timeClient(ntpUDP, "us.pool.ntp.org", TIMEZONE_OFFSET, NTP_UPDATE_INTERVAL);

Use regional NTP servers for faster sync:

• North America: us.pool.ntp.org
• Europe: europe.pool.ntp.org
• Asia: asia.pool.ntp.org

Add More Family Members

Currently limited to 4 members due to available GPIO pins. To expand:

1. Use GPIO expander (MCP23017)
2. Use ESP32 instead (more GPIO pins)
3. Use multiplexing

Change Update Frequency

delay(60000); // Check every minute (default)
delay(10000); // Check every 10 seconds (more responsive but higher power usage)

Acknowledgements

• NTP library by Fabrice Weinberg
• TimeLib by Michael Margolis
• Don Zagier
• Sieve of Eratosthenes

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