🥧 Pi Day 2026 Experiments

Experiment 1: LED Morse Code "3.14159"

What It Does

A green LED blinks the digits of Pi (3.14159...) in Morse code. Short flash = dot, long flash = dash. Green LED ties into St. Patrick's Day too! 🍀

Components Needed

Wiring

Code: pi_morse.py

# pi_morse.py — Blink Pi digits in Morse Code
# Pi Day TikTok Livestream — ProTechTrader Make: Radio Kit Demo
# Upload to Pico #1, run with Thonny

from machine import Pin
from time import sleep

led = Pin(15, Pin.OUT)  # GP15

# Morse code timing (seconds)
DOT = 0.15        # Short flash
DASH = 0.45       # Long flash (3x dot)
SYMBOL_GAP = 0.15 # Gap between dots/dashes
CHAR_GAP = 0.45   # Gap between digits
WORD_GAP = 1.0    # Gap between repetitions

# Morse code for digits 0-9 + decimal point
MORSE = {
    '0': '-----',   # 5 dashes
    '1': '.----',   # 1 dot, 4 dashes
    '2': '..---',   # 2 dots, 3 dashes
    '3': '...--',   # 3 dots, 2 dashes
    '4': '....-',   # 4 dots, 1 dash
    '5': '.....',   # 5 dots
    '6': '-....',   # 1 dash, 4 dots
    '7': '--...',   # 2 dashes, 3 dots
    '8': '---..',   # 3 dashes, 2 dots
    '9': '----.',   # 4 dashes, 1 dot
    '.': '.-.-.-',  # Decimal point
}

PI_DIGITS = "3.14159265358979323846"

def blink_morse(char):
    """Blink one character in Morse code"""
    pattern = MORSE.get(char, '')
    for i, symbol in enumerate(pattern):
        led.on()
        if symbol == '.':
            sleep(DOT)
        else:
            sleep(DASH)
        led.off()
        if i < len(pattern) - 1:
            sleep(SYMBOL_GAP)

def main():
    print("=== Pi Day Morse Code ===")
    print(f"Blinking: {PI_DIGITS}")
    print("Dot = short flash, Dash = long flash")
    print("Watch the LED on GP15!")
    print()
    
    while True:
        for char in PI_DIGITS:
            morse = MORSE.get(char, '?')
            print(f"  {char}  {morse}")
            blink_morse(char)
            sleep(CHAR_GAP)
        
        print("\n--- Looping ---\n")
        sleep(WORD_GAP)

main()

How to Run

Experiment 2: LCD Scrolling Pi Digits

What It Does

The 1602 LCD screen scrolls the first 100 digits of Pi infinitely. Shows a "Pi Day 2026! / ProTechTrader" splash screen on startup. Very visual for camera!

Components Needed

Wiring — Only 4 Wires!

Connection Reference Photos

Click any image to view full size. Use these as a visual guide while wiring.

3D View — Overall Connection Layout

Close-Up — Pico Pin Connections

Close-Up — LCD I2C Backpack + Contrast Dial

Cartoon Wiring Diagram — Color-Coded

Full Setup — Desk Layout with Laptop

Lifestyle Shot — Maker Workshop

📌 Pico Pinout — LCD Wiring Reference

Physical pin numbers (1-40). The 4 highlighted rows are the only pins you need for this experiment.

Connect: Pin 6 SDA Pin 7 SCL Pin 38 GND Pin 40 VBUS

Complete Beginner Guide: Step by Step

Never programmed before? No problem. Follow every step below and you'll have scrolling Pi digits in about 15 minutes.

Pre-Setup: Upload Libraries First!

Download these two files and save them TO the Pico via Thonny (File → Save As → Raspberry Pi Pico):

Verify Wiring: i2c_scan.py

# i2c_scan.py — Find your LCD's I2C address
# Run this FIRST before pi_lcd.py to verify wiring!
# Most LCDs are 0x27, some are 0x3F

from machine import Pin, SoftI2C

i2c = SoftI2C(sda=Pin(4), scl=Pin(5), freq=400000)
devices = i2c.scan()

print("=== I2C Scanner ===")
if devices:
    print(f"Found {len(devices)} device(s):")
    for d in devices:
        print(f"  Address: {hex(d)} ({d})")
    print()
    if 0x27 in devices:
        print("LCD at 0x27 — default, no code changes needed!")
    elif 0x3F in devices:
        print("LCD at 0x3F — change I2C_ADDR in pi_lcd.py to 0x3F")
    else:
        print("Unexpected address — update I2C_ADDR in pi_lcd.py")
else:
    print("No I2C devices found!")
    print("Check wiring:")
    print("  SDA -> GP4 (Pin 6)")
    print("  SCL -> GP5 (Pin 7)")
    print("  VCC -> VBUS (Pin 40) — must be 5V!")
    print("  GND -> GND (Pin 38)")

Code: pi_lcd.py

# pi_lcd.py — Scroll Pi digits on 1602 LCD
# Pi Day TikTok Livestream — ProTechTrader Make: Radio Kit Demo
# PREREQ: Upload lcd_api.py and pico_i2c_lcd.py to Pico first!
# Upload this to Pico #2, run with Thonny

from machine import Pin, SoftI2C
from pico_i2c_lcd import I2cLcd
from time import sleep

# --- CONFIG ---
I2C_ADDR = 0x27    # Most common. Change to 0x3F if yours is different
I2C_ROWS = 2
I2C_COLS = 16
SDA_PIN = 4        # GP4 (Pin 6)
SCL_PIN = 5        # GP5 (Pin 7)
SCROLL_SPEED = 0.3 # Seconds between scroll steps

# --- SETUP ---
i2c = SoftI2C(sda=Pin(SDA_PIN), scl=Pin(SCL_PIN), freq=400000)
lcd = I2cLcd(i2c, I2C_ADDR, I2C_ROWS, I2C_COLS)

# First 100 digits of Pi
PI = ("3.14159265358979323846264338327950288419716939937510"
      "58209749445923078164062862089986280348253421170679")

def scroll_pi():
    """Scroll Pi digits across top row, static message on bottom"""
    lcd.move_to(0, 1)
    lcd.putstr(msg_display)
    
    pos = 0
    while True:
        display = ""
        for i in range(I2C_COLS):
            display += PI[(pos + i) % len(PI)]
        
        lcd.move_to(0, 0)
        lcd.putstr(display)
        
        pos = (pos + 1) % len(PI)
        sleep(SCROLL_SPEED)

def main():
    print("=== Pi Day LCD Display ===")
    print(f"Scrolling {len(PI)} digits of Pi")
    print(f"I2C Address: {hex(I2C_ADDR)}")
    print(f"SDA: GP{SDA_PIN}, SCL: GP{SCL_PIN}")
    print()
    
    lcd.clear()
    
    # Splash screen
    lcd.move_to(0, 0)
    lcd.putstr("  Pi Day 2026!  ")
    lcd.move_to(0, 1)
    lcd.putstr(" @ProTechTrader ")
    sleep(3)
    
    lcd.clear()
    scroll_pi()

main()

Software Setup

Step 1: Install Thonny IDE

Step 2: Flash MicroPython on Pico

Step 3: Connect Thonny