1Set up the Raspberry Pi
2Electrical Connection of Sensores and Actuators
2.1AD Converters connected via SPI
2.2Relay on GPIO via Opto-Coupler
2.3PWM Control of Ventilation via i2c
2.4OneWire Temperature Sensor
2.5Ultra-sonic Distrance Measurement
2.6Serial RS232 connection
2.7Stepper Motor Control
3Heating Control
4Ventilation Control (Paul Lüftung, Thermos 200)
5 z-wave


To operate the bypass one pin for opening and one for closing is used. If both pins should be switched on, this indicates a fast stop to the motor, defined by the full-bridge driver L298.

I experienced that the L298 comes with a voltage drop of 3 V. Therefore, to drive the Bosch VMC 24V of my Bypass, I need a voltage supply of 29 V at least.