Hardware circuit and diagram for interfacing to the Webasto WBUS interface from a PC/Arduino
This small circuit allows you to connect a 5 volt device with a serial port to a Webasto Heater which communicates in the WBUS protocol.
The circuit expects you to connect a FT232R USB Serial to TTL interface, or a micro controller such as the Arduino.
Its a http://fritzing.org/home/ circuit/file so you can make a PCB from it if you want (not tested!).
It uses hardly any parts, costs less than £1 (GBP) to make.
Amount Part Type Properties 1 Generic female header - 3 pins row single; hole size 1.0mm,0.508mm; pin spacing 0.1in (2.54mm); pins 3; form ♀ (female); package THT 3 NPN-Transistor variant variant 2; type NPN (EBC); package TO92 [THT]; part # BC548 NPN 1 Generic female header - 6 pins row single; hole size 1.0mm,0.508mm; pin spacing 0.1in (2.54mm); pins 6; form ♀ (female); package THT; part # FTDI BASIC 1 Yellow (595nm) LED color Yellow (595nm); package 3 mm [THT]; 1 PNP-Transistor type PNP (CBE); package TO92 [THT]; part # BC557 PNP 4 10kΩ Resistor bands 4; tolerance ±5%; pin spacing 400 mil; resistance 10kΩ; package THT 3 1kΩ Resistor bands 4; tolerance ±5%; pin spacing 400 mil; resistance 1kΩ; package THT
Have fun!