• Wiring
• Voltage converter
• Audio connection cable
• Control cable
• Pictures
• Operating in the car

Voltage converter:

• The voltage converter is connected with a 2-cored cable (cores as thick as possible) to a car cigarette lighter connector.
• This connector is then plugged into the car cigarette lighter socket.

ATTENTION
• Please check the current consumption on the 12V side of the voltage converter before (with PC running !).
• Then check if the fuse of the car cigarette lighter is allowing that current.
• Otherwise connect directly to the battery, but with fuse between (ABSOLUTELY NECESSARY !).
• Never connect unfused loads directly to the battery !

• The audio connection cable connects the audio output of the PC (sound card or output of sound adjustment card) to the line-in input of the car radio.
• I'm using a Blaupunkt Casablanca car radio, that has to be connected with a Mini-DIN-ISO connector (Blaupunkt specific) on the rear side.
• This special connectors sometimes are difficult to purchase, but you may find them in car utility shops or in specialized car stereo shops.
• The pins of the connector sometimes have to be bought separately from the plastic socket (3 pins are needed).
• On the PC side, a normal 3,5mm jack plug is needed (I used a 90° cranked one, because the cable conduit in the car was easier that way).
• You should use a 2-cored, shielded audio cable, explicitely specified for audio purpose, because the cable might get a length of some meters. So the risk of interferences on the long cable is less.

Audio cable
Blaupunkt radio line-in (Mini DIN-ISO) to PC (3,5mm jack plug)

Control cable:

• The control cable connects the Num pad to the PC and has different functions.
• First of all the keyboard itself.
• My PC has a switch button and no 220V switch as power on button.
• So it's possible to build in such a low voltage switch button into the num pad and to switch on the PC remotely from the num pad.
• If the PC uses a 220V AC switch, you would need to connect the num pad with a 220V power cable to the num pad (!!). That means also, that there are 220V AC inside the num pad. In case of any defect that might destroy everything, including the driver.
• Additionally I have mounted a LED into the num pad, that is connected to the power LED of the PC.
• That indicates at the num pad, if there is power available at the PC. I think this is very useful, if nothing works. Then you are able to see from the driver seat, if the PC is power supplied.
• I am using a standard 10-cored shielded control cable with thin cores, as it is used for different general purposes.
• First of all the standard cable, as it comes with the num pad, is disconnected from the num pad (that's because I wanted only one cable instead of some).
• The PS2 connector of the num pad's standard cable normally can not be used, because it is weld together with the cable.
• Now the old num pad cable has to be ohmically measured between each core and the PS2 connector's pins. That is to get a relation between the core cable colours and the PS2 connector pins.
• 4 cores and the shield of the new control cable are now soldered at that points of the num pad, where the old cable was connected.
• After that you solder a new PS2 connector on the other side of the new control cable (logically according to the previously evaluated relation).
• Now you drill a whole in one of the slot base plates and mount any 4-pin socket there (I used a 4-pin DIN socket).
• 2 cores of the control cable are now soldered to the LED, 2 other cores are soldered to the switch button in the num pad.
• This 4 cores are now soldered to a corresponding 4-pin male connector on the other side of the control cable.
• The Y cable end (PC side) is held together with adhesive tape or shrink sleeves.
• That's it, the control cable is ready.
• Now the LED and the switch button have to be internally connected to the socket in the slot base plate of the PC.
• Therefore the power LED of the PC is disconnected from it's original cable.
• The switch button of the num pad is connected in parallel to the switch button of the PC.

Control cable
num pad (with power switch button and power LED) to the PC (keyboard, power LED, power switch button)

	Connection to the car cigarette lighter (connector with LED, that indicates if the car cigarette lighter is supplied with 12V)
	PC in the trunk (unfortunately there was not enough space below the back seat ;-(
	Num pad laterally can be seen: Power-on switch button to switch on the PC The green power LED
	Rear view of the slots from left upper side to right lower side: The sound adjustment card with 4 adjust buttons (volume, base, treble, balance) and the audio output (3,5mm jack plug) to the car radio. Empty slot base plate with 4-pin DIN connector (control cable with power LED and power switch button). PS2 connector for the keyboard. The Y control cable, protected with shrink sleeves.
	Inner view of the slots from upper side to lower side: Additional IDE controller Sound adjustment card Empty slot base plate with female 4-pin DIN connector
	Voltage converter (view from front side of seat) Mounted below the driver seat The voltage converter gets hoter on the bottom side than on the upper side. Voltage converter is mounted upside down (because of cable conduit and heat rejection). The red power-on switch is accesable from the front side of the seat.
	Voltage converter (view from rear side of seat) White 2-cored cable in the middle (12V) leads to the car cigarette lighter. Light grey 220V power cable (to right bottom side) leads to the PC in the trunk.

• The engine is running and the car cigarette lighter is power supplied.
• Put the connector of the voltage converter into the car cigarette lighter.
• Switch on the voltage converter.
• Switch on the PC with the power switch button of the num pad.
• Change the audio source of the car radio to line-in.
• Wait until PlayIt plays the start message acustically.
• The number of the album is announced.
• MPxPlay starts to play music.
• To end, press ",".
• PlayIt plays acustically the end message.
• Now type in a new number or press 2 x NUM to switch off the PC.
• The shutdown message is announced.
• After ca. 1s the PC switches off.
• Now switch off the voltage converter, otherwise it might decharge the battery.
• The detailed sequence can also be read here.