The mikrocontrollerI used the same type of mikrocontroller as for the one-wire controller: AT90CAN128. It has a CAN interface, which I knew how to use. The PCA82C250 I use for the CAN transceiver.
The power supplyThe power supply contains the same chips as for the one-wire controller. The step down contoller
LM2575 converts 12V DC to 5V DC and drives the digital chips. The 12V DC comes along with the CAN bus cable, which I have installed inside my basement.
The 220V driversTo drive the ventilators, I use two S202 S12 solid state relais. Each relais contains a digital input, which can be directly connected to the mikrocontroller. I also added varistors and fuses for circuit protection.
Below a picture of the circuit I created. The red lines indicate the chip positions.