An Arduino Nano, an old mobile phone display and a GY-BM E/P 280 sensor will give you a geeky thermometer/barometer.

Here is a photo:

• 1 x Arduino Nano (or as in my case a Chinese clone)
• 1 x 200 Ohm resistor
• 1 x breadboard
• 1 x GY-BM E/P 280 sensor
• 1 x Nokia 5110 display
• a lot of cables

To make this work you have to make a change in the Adafruit BMP 280 Library: Change the I2C address in Adafruit_BMP280.h to 0x76. If you forget this, the library won't be able to find the sensor.