Raspberry Pi Pico Mini Weather Station (DHT22 + OLED Chart)

How has your room's temperature changed over the last two minutes? The **Raspberry Pi Pico** reads temperature and humidity from a **DHT22** every 2 seconds and shows the value in big digits on a **0.96 inch OLED**, with a **line chart** of the last 60 readings below. An arrow shows the trend and the temperature and humidity pages swap every 4 seconds. The OLED driver is built into the code: one file, no libraries.