Quantity   Component name
2 × DHT22 Temperature and humidity sensor plus pull-up resistor
2 × BMP180 Barometric pressure, temperature, and altitude sensor. Adafruit version on breakout board with 5v conversion onboard
1 × 20x4 LCD display White on blue with backlight
1 × P2N2222 Transistor Helps control the LCD's backlight via one of the Arduino's PWM pins
1 × 1N4001 Diode Helps control the LCD's backlight via one of the Arduino's PWM pins
1 × 560 Ohm Resistor Helps control the LCD's backlight via one of the Arduino's PWM pins