External temp probe is a DS18B20, other sensors part of Sense Hat

The data on this page was assembled by a Python script that collects sensor data from a Sense Hat attached to a Raspberry Pi. One temperature probe external to the Sense Hat, but connected to the same Raspberry Pi, is included. The temperature probe included with the Sense Hat indicates a higher temperature than the external probe because the Sense Hat sensor is heated by the Raspberry Pi and Sense Hat electronic circuits. The external temp probe was located about three inches from the Raspberry Pi and is a much better indicator of the room temperature.

The Sense Hat connects to six of the GPIO pins of the Raspberry Pi (GPIO pins 2, 3, 8, 23, 24, and 25, which are physical pins 3, 5, 16, 18, 22, 24). The Sense Hat was connected to the Raspberry Pi with a GPIO Stacking header rather than the header provided with the Sense Hat. The stacking header has longer pins, which protrude above the Sense Hat. This allows for connection of the external temperature probe to GPIO pin 4 which is not used by the Sense Hat.