Webasto Preheater Control Unit (Arduino + Webasto = Ardubasto)
They installed me on a car pre-starting Webasto heater. After installation, it turned out that it is not controlled by a discrete signal (as on my previous car), but only via the digital W-bus. The W-bus, by electrical parameters, is analogous to the K-line bus and for it there is an K-line integrated converter - RS232TTL - this is the L9637D chip. On this chip, based on Arduino, it was decided to make heater control. The task was complicated by the fact that Arduino supports only the serial port transmission protocol without parity, and the W-bus protocol works with the settings of the 2400/8-E-1 port. To get around this, the waveforms of the Webasto start command were taken and the commands to Webasto were implemented with timing delays.
Control Unit Functions:
1) When power is supplied to the control unit via normally open alarm output contacts (with remote control via SMS), the unit continuously sends a heating command to the W-bus.
2) When connecting Arduino to a computer via USB and using Webasto diagnostic programs, it is possible to diagnose, manage and erase heater errors. To do this, you need to load an empty sketch.
Scheme of the device in AutoCad format.
Appearance
Sketch
This was the first fully functional implementation of the control unit.
Further development, not yet fully realized is the implementation of the following functions and characteristics of the device:
1) Control the activation via SMS from the signaling unit Webasto - when the contact signalization is short-circuited, the Arduino should be self-powered according to the power of Webasto.
2) Complete the device with a monochrome display such as Nokia 5110.
3) Display the temperature of the coolant and the voltage of the car battery received from Webasto via W-bus.
4) Display Webasto operation status
5) Webasto must be switched off either at a sufficient coolant temperature or at a low voltage of the car battery.
6) Sound alarm (melody) on / off Webasto, button press, etc.
7) Turn on / off Webasto from the button on the device.
8) Navigation light control - when the power supply to consumers of the 2nd group appears - turn on and when the dimensions turn on or the voltage of the car battery drops below 13.5 volts (polite backlight) - turn off.
All this is basically implemented and described in the control algorithm e (program format yED).
Scheme in AutoCad format
Signet
The device itself front view and rear view is
implemented, but not fully debugged and there are problems with the display - the first installed one refused to work, the second one is also buggy. Perhaps I will switch to the OLED display.
Thanks for attention.
Control Unit Functions:
1) When power is supplied to the control unit via normally open alarm output contacts (with remote control via SMS), the unit continuously sends a heating command to the W-bus.
2) When connecting Arduino to a computer via USB and using Webasto diagnostic programs, it is possible to diagnose, manage and erase heater errors. To do this, you need to load an empty sketch.
Scheme of the device in AutoCad format.
Appearance
Sketch
This was the first fully functional implementation of the control unit.
Further development, not yet fully realized is the implementation of the following functions and characteristics of the device:
1) Control the activation via SMS from the signaling unit Webasto - when the contact signalization is short-circuited, the Arduino should be self-powered according to the power of Webasto.
2) Complete the device with a monochrome display such as Nokia 5110.
3) Display the temperature of the coolant and the voltage of the car battery received from Webasto via W-bus.
4) Display Webasto operation status
5) Webasto must be switched off either at a sufficient coolant temperature or at a low voltage of the car battery.
6) Sound alarm (melody) on / off Webasto, button press, etc.
7) Turn on / off Webasto from the button on the device.
8) Navigation light control - when the power supply to consumers of the 2nd group appears - turn on and when the dimensions turn on or the voltage of the car battery drops below 13.5 volts (polite backlight) - turn off.
All this is basically implemented and described in the control algorithm e (program format yED).
Scheme in AutoCad format
Signet
The device itself front view and rear view is
implemented, but not fully debugged and there are problems with the display - the first installed one refused to work, the second one is also buggy. Perhaps I will switch to the OLED display.
Thanks for attention.
