Glossary

Block: A wireless bridge that runs Slate firmware, acting as a router and controller between WiFi/Bluetooth and hardware buses. Features LIN for retrofitting heaters using stock wiring, RS-485 for new builds, WiFi and Bluetooth for user connectivity, and 4 RGB status LEDs. Designed to be IP68 compliant.
Fusain: The serial communication protocol used between Thermoquad devices. Open, documented, and designed for extensibility.
Glow Plug: A resistive heating element used to ignite fuel in diesel heaters. Draws approximately 10 amps and heats a metal mesh in the combustion chamber. Fuel vaporizes and ignites on contact with the hot mesh. Appears to be ceramic construction; further research is needed.
Hades: The ICU board that runs Helios firmware. Connects to heater components and replaces the stock control board. Based on the RP2350.
Heat Exchanger: The chamber where combustion heat transfers to air blown into the heated space. In diesel heaters, the combustion chamber is surrounded by the heat exchanger. A fan blows ambient air over the heat exchanger’s outer surface, absorbing heat and delivering warm air to the cabin or space.
Helios: The Ignition Control Unit firmware for burner control. Runs on Hades hardware, or a Raspberry Pi Pico 2 for prototyping.
Heliostat: Development tool for Fusain protocol analysis and debugging.
ICU: Ignition Control Unit. The controller that manages burner operation including ignition, combustion, and shutdown sequences.
IP Code: Ingress Protection Code, a classification system defined by IEC 60529 that rates protection against solid objects and water. Format is IP[X][Y] where the first digit (0-6) indicates solid particle protection and the second digit (0-9) indicates water protection. IP68 means dust tight with continuous water immersion capability. See IP Code on Wikipedia.
LIN: Local Interconnect Network. A low-cost single-wire serial protocol used in automotive applications, operating at up to 20 kbit/s. Used in Thermoquad for retrofitting heaters with stock wiring. See LIN on Wikipedia.
Luna: A handheld client device with an OLED display and 3 buttons. Battery powered and IP68 compliant, designed for use in dark settings. Can be wall mounted with hardwired power (5V-36V). Connects wirelessly to a Block.
PID Controller: Proportional-Integral-Derivative controller. A control loop feedback mechanism that continuously calculates an error between a setpoint and measured value, adjusting output to minimize error. Used in Thermoquad to maintain heat exchanger temperature by adjusting fan speed. See PID Controller on Wikipedia.
Pump Pulse Rate: How often the fuel pump receives power, expressed in milliseconds. A pump has a pulse duration (typically 50ms) that drives the solenoid and moves the piston, pumping fuel. A spring then pushes the piston back to its reset position during the recovery period (also typically 50ms). The maximum pump rate is the pulse duration plus the recovery period.
Roastee: A client progressive web app for desktops and phones. Connects to Block and Luna devices via WiFi or Bluetooth for remote monitoring and control.
RP2350: Raspberry Pi’s dual-core Cortex-M33 microcontroller. All Thermoquad hardware is based on this chip.
RS-485: A serial communication standard defining electrical characteristics for balanced, multipoint systems. Uses differential signaling on two wires, supporting distances up to 1200 meters and speeds up to 10 Mbps. Used in Thermoquad for new builds and multi-heater installations. See RS-485 on Wikipedia.
Slate: The thermostat and control hub firmware. Manages temperature regulation and serves as the integration point for automation systems. Runs on Block and Luna hardware, or a Raspberry Pi Pico 2 for prototyping.
West: Zephyr’s meta-tool for workspace management.
Zbus: Zephyr’s publish-subscribe messaging system.