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General System Description
The BCM RF-remote control system is a subsystem of a Body Computer Module (BCM) for
an automotive carline.
It consists out of a tuning free RF- transmitter in the keyhead (container concept) and the
receiver module, which is directly soldered on the printed circuit board of the BCM control
unit.
The receiving distance around the vehicle is typically more than 4 meters.
General description RF transmitter
The BCM transmitter is equipped with an integrated antenna for the reception of the RF
signal within the PCB.
The transmitter is used to transmit information for locking and unlocking the vehicle by
unidirectional RF-transmission. The RF key consists of a plastic container with a battery
powered RF- transmitter PCB inside. The electronic subassembly is realized in SMD
technology on a double sided FR-4 printed circuit board and is supplied by a 3V Lithium
battery.
The antenna is integrated on the PCB. The design of the plastic housing allows the user to
change the battery.
A microcontroller monitors the buttons, calculates the next data protocol with a specified
algorithm and activates and modulates the transmitter with the appropriate data telegram.
The RF key is normally in inactive state with very low power consumption. If one of the
buttons is pressed for more than 20 ms (debounce time) the key will be activated and
transmit at least 5 telegrams.
Once activated, it generates and transmits the associated data stream for the pressed key.
Pressing the button is visually indicated by a flashing LED.
After the user releases the button, the RF key returns to inactive state.
Buttons
The transmission is activated by pressing the pushbuttons:
Button 1:
lock central door locking and theft protection
(Lock) comfort closing (if button 1 is pressed for more than 0,5 sec.)
Button 2:
unlock central door locking
(Unlock)
Transmitter Versions
PN Customer
PN Conti
Description
93316265
5WK4 8668
transmitter 433 MHz,
housing with customer logo
93316265
5WK4 8669
transmitter 433 MHz,
housing without customer logo
The difference between the two versions is the customer logo outside on the transmitter
housing.
Both versions use the same PCB, layout and assembly.