Open-Source Microcontrollers for Science - Open-Source Lab: How to Build Your Own Hardware and Reduce Research Costs - page 65

Table 4.3
Bill of Materials for the Polar Bear Open-source Environmental Chamber
The Polar Bear Chamber is made up of eight subsystems, all controlled by the Arduino,
which will be individually detailed in wiring diagrams below:
The LCD interface, which enables feedback to the system operator on the state of the sys-
tem.
The keyboard interface, which enables the system operator to input desired environmental
conditions and run the Arduino sketch.
The thermistors that measure the chamber temperature.
The humidity sensor that measures the relative humidity within the chamber.
The power resistors that are used to heat the chamber when the chamber temperature is
below the temperature set point.