Thread: E46 - CarPC Work Log

I have investigated the pinout on the motor and sensor pcb of the BM.

Motor draws 110mA at 6V, but if door is jamed the motor draws 190mA. It is not more than 190mA since there is a clutch so that the motor still moves even if door is still.

Because of the motor being a 6V motor I have desided to build my own H-bridge with P-FET and current limiting NPN transistors so that there is no need for 6V regulator. Smaller, cheaper and better.

I will order pcb's next week, that is week 38 instead of 34....


I count from left to right on picture

pin2.1 : 3v3 active low when open
pin2.2 : 3v3 active low when close
pin2.3 : 5V supply
pin2.4 : 0-5V, and minimum when closed.
pin2.5 : GND

Turns out I need to extend the flat cable for the lcd controller. It was long enough but it was upside down. Once folded to get correctly into connector it was far too short.

I have to do this to find out the button interface.

Long story: further delays:-(

On this pic is the 50 wire connector on the low edge on the board. It also shows how I had to move a couple of components in order to fit the DVD on top.

:-) I wish I could (/had room/a second car) for doing a little more of those greasy jobs.
For the time being I do not lack any BM parts, but good to know, thanks!

I have now extended the flatflexi. First time I've seen something on my second BM!

I have found that the buttons can be simulated with the help of two DAC's, or as I will do it, one DAC and two analogue switches.



Pin on keyboard flat flexi counting towards cut edge:
4 GND, 6 buttons, 7 joystick.

Button Voltage
None 3.3V
Power On 2.2V
PCPWR 1.65
Mode 1.25V
Band 0.845V
Scan/Sel 0.440V
Mute 0V


Joystick Voltage
None 3.3V
Up 0.440V
Right 1.635V
Down 0.840V
Left 1.250V
Press 0V

So now there's no excuse anymore. I must complete the design :-)

Well, I've seen that you have got your screen running for a long time now. I do not like to try things out, so I did not test my monitor when I got it. I just took it to pieces right away :-)

I was wondering.... What DVD drive will you use?

I opened up the front behind the door as I had a TAPE BM and I also wanted to get better access when assembling cables and pcb's. My intention is to put a thin, black, L-shaped plate in there.



It holds
- the mouthpiece of a CD BM,
- holes for positioning LED's on the sides of the DVD mouthpiece
- hole for a jam detection LED (lit when there is a CD in the mouthpiece so that the door cannot be closed) I might loose that one...
- support for the DVD. (An edge on the inside that the DVD can lean on)
- holes for the optic sender and receiver. CD in mouthpiece detector. Fork, kind of. Invisible assembly.

Should I make one for you too?

I have also posted a message on hacktheibus of the last questionmark to be straightened out. About backlighting. Adam, a friend of mine in Australia, has a backlight on his panel that can be controlled with 0-5V. I will generate that voltage from car dash backlight as well as from the PC sending messages on COM port.

Thoughts on this?

Oh, no. It seems like you are going thru a rough patch, aren't you. Sorry....

I jump right into business, but that does not mean I do not feel for you...
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I have a BM CD player. And a tape one-- But thanks

I am using a Panasonic slot-in player. I am sure you will have room for any player. And it will work fine to use existing panel. Maybe you have seen my first BM? (LED's are mine) I am sure yours will look very much like this. Well, apart from your larger screen :-)


I have just made a layout. I will review it during this week to avoid silly straps. I am sure there will be a few anyway.

This is how it will be assembled in the BM: (first proto)


This is a drawing with its connectors

Here is a better resolution pic:
http://web.comhem.se/mulle4/dash_drawing_2.jpg

DC Motor Function
When the button is pressed (mid top edge) the door starts to open. When it is opened the DVD is triggered to eject CD that might be inside. (low left corner output)
When button is pressed again, the door will close unless there is a CD not fully inserted blocking the jam sensor. (mid low edge)
If there is to great mechanical resistance that slows down the opening or closing, the movement is canceled and door is going back to original position
Instead of a button press, serial COM messages can be sent to the pcb via IBus or RS232 adapter from the car PC to command the door to open or close.

Control of Ignition (LCD panel on)and rearview signal (select AV2) to the LCD panel
There is two ways of letting the pcb control the LCD panel and select AV2 or VGA. Via buttons and/or via commands on serial channel (IBus or RS232 adapter) from carputer

Full power control Function
The pcb has a state machine, controlling the system. It will make your carputer installation feel OEM. It will listening in on IBus communication if you have a BMW, or you can connect various inputs to detect the same events that is read from the IBus line.

It will control PC on and off, lcd panel on and off, power amp on and off (remote input) and USB power on and off.
The two LED's (top edge to the right) will indicate the state, booting, shutting down etc.

When you unlock the car/insert ignition key/ press 'on', the PC will start to boot to save booting time. (or exit hibernation/standby)
When PC has booted the LCD will be turned on. No windows hello or byebye screens. The poweramp will also be enabled. No speaker bumps.

The PC can be kept running for 30 minutes after ignition off. Then it is shut down if you do not press 'on' within 30s.

When pressing 'on' with ignition on, only the LCD and power amp goes off, giving you instant access if you press on again.=Immidiate on off action once booted

Holding 'on' for 1-2s will shutdown the PC.

BM on-off button (or steeringwheel buttons) can be used as PC on-off.

In short, OEM feel

Not all code has been written yet, and some code has been running on older 8051 platforms. I suggest that you get a $69 eval kit including emulator from silabs to be able to update code.

Edit->
Oh yeah, I forgot. There is a 0-5V output for brightness control. The LED backlight driver.
Edit2->
and button interface so that I can control brightness and all other menu settings from the PC. With my Hiinfo N52, but I am sure that can be adapted to other LCD's fairly easy.