HomeIO : Automatically actuated ac vents and smart thermostat

Electronics, Firmware, & Mechanical design

HomeIO is a system of smart vents and a central thermostat that allows zone control of a house without dampeners. The system is cheap and easy to install. The vents are daisy-chained together and each is motorized and has sensors.

Vents consist of:

  • 8-bit micro
  • Isolated RS-485 bus
  • Motor driver (using stall current to detect open or shut)
  • BMP280 (pressure, temperature, humidity sensor)
  • Ambient light sensor
  • Capacitive touch pad (for setup ID assigning during installation)

Thermostat control board consists of:

  • 6 solid-state relays for system control (AC, heater, furnace, etc.)
  • ARM M0+ micro
  • Isolated RS-485 bus
  • Power management and monitoring circuitry  (short-circuit protection, ESD protection)