Turn Your Plant Into a Pet - Complete Wiring Guide
📺 LCD Display → Raspberry Pi
LCD Pin
Wire
Pi Pin
GPIO
VCC
Red
Pin 1
3.3V
GND
Black
Pin 9
Ground
DIN
Green
Pin 21
GPIO 9 (MOSI)
CLK
Purple
Pin 23
GPIO 11 (SCLK)
CS
Brown
Pin 24
GPIO 8 (CE0)
DC
Gray
Pin 37
GPIO 26
RST
Pink
Pin 36
GPIO 16
BL
Cyan
Pin 19
GPIO 10
📊 ADS1115 ADC → Raspberry Pi
ADS Pin
Wire
Pi Pin
GPIO
VDD
Red
Pin 1
3.3V
GND
Black
Pin 9
Ground
SCL
Orange
Pin 5
GPIO 3 (SCL)
SDA
Blue
Pin 3
GPIO 2 (SDA)
🌡️💧☀️ Sensors → ADS1115
Sensor
Sensor Pin
Connects To
LM35 (Temp)
VCC
3.3V Rail
OUT
ADS1115 A1
GND
Ground Rail
Moisture
VCC
3.3V Rail
OUT
ADS1115 A2
GND
Ground Rail
LDR (Light)
VCC
3.3V Rail
OUT
ADS1115 A3
GND
Ground Rail
🎨 Wire Color Reference
Red - 3.3V Power
Black - Ground
Blue - I2C SDA
Orange - I2C SCL
Green - SPI MOSI
Purple - SPI SCLK
Brown - SPI CS (CE0)
Gray - LCD DC
Pink - LCD Reset
Cyan - LCD Backlight
Yellow - LDR Signal
⚡ Important Wiring Notes
Use a Logic Level Converter! The Pi's GPIO runs at 3.3V. If any sensor outputs 5V, use a bi-directional level converter to avoid damaging the Pi.
Use the LM35, NOT DS18B20. The code requires an analog temperature sensor. The DS18B20 is digital and won't work without code modifications.
Check ADS1115 channel assignments. The original Instructables diagram shows different channels. Wire as shown here to match the code (A1=Temp, A2=Moisture, A3=Light).
Enable I2C on the Pi. Run sudo raspi-config → Interface Options → I2C → Enable. Also disable Serial.
Double-check pin numbers! The Pi Zero uses the same 40-pin header as the Pi 4, but some tutorials reference the Pi 4 specifically.
Test sensors individually first. Use calibration.py to verify each sensor works before final assembly.