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Hi,

This is my first post on this forum, and I would like to say that after a few hours reading through some posts, I am very impressed with all the work that has been done concerning the IP-BUS and Pioneer head unit!

I have a Pioneer head unit and the IP-BUS cable. I was looking for a way to control the computer through the head unit and found this forum. The problem is I have no knowledge of electronics and I also don't want to add more hardware to the setup I have, so building a hardware emulator and the YAMMP3 is not really an option. From what I have read, the hardware emulator interprets the data from the head unit and converts it to a standard RS232 format. Can the IP-BUS cable be connected directly to a serial port on a computer where software interpets and converts the data into commands which can control a software MP3 player?

If this is possible, it would be very good.

Thanks for any help.

Damian.

The IP-BUS cable can't be directly connect to RS232 PC port, it only can connect acros "converter" that been convert RS232 command in/to IP-BUS
Converter-emulator can be build based on schema of present on this forum EMULATOR, with added RS232 level converter (MAX232) end correction of soft in microcontroller.

Hi, I also want to connect IP-Bus to computer.
Is the only thing necessary, is to connect CAN-BUS IC to MAX232, then connect MAX232 to serial port?
If yes, then what settings are necessary (baud rate, bits, parity)?

Is it possible to connect a converter to the IP-Bus when there is already another device on it?
My goal is to use the converter to "listen" to the IP-Bus and log all communication on it.  I want to decode the XM Radio mode.

Also, before I start, has the XM Radio mode already been decoded?

No. Protocols and levels are very different.

You can connect converter between HeadUnit and another device directly to IP-Bus and connect converter out from MAX232 to serial port. Upload logging firmware and listen communication.

I am a little confused.  How come the Atmega8 UART can be programmed to talk to the CAN-BUS IC, but an RS232 port cannot, not even through MAX232?  I thought RS232 uses a UART too?

Is any extra circuitry required to connect converter between head unit and another device?  Or can it just be connected in parallel like a Y-splitter?

Is a logging firmware already available, or would I need to modify your Yammp3 firmware to turn it into a logging firmware?  I did a search and found no references to logging firmware.  Unfortunately, I am unfamiliar with the C language.

ATMega UART can't be programmed to talk with CAN-BUS IC! ATMega UART only for RS232 to PC or other UART device like MP3 player.
Look to the shematic diagramm from main site hardly!
Connect converter to IP-Bus parallel like spliter. If converter not be transmit any data - your HU and another device be working fine.
logging firmware (http://vitat.spb.ru/files/ip-bus/ipbus_logger.zip).

Ok, I think I understand.  I looked at schematic and see RX and TX connected to INT0 and ICP.
I was trying to learn by reading C source, but I don't know C so I misunderstood it for using the UART.
Thanks for the logging firmware!

Is Atmega64 compatible with Atmega8 firmware?

No.

Does the attached schematic look correct if I want to convert between IP Bus and 5V Serial?
I will use an external circuit to convert 5V serial to RS-232 so that part isn't in the schematic.

Swap the RX(4) and TX(14) pins at Mega8.
Swap the 2 and 3 input pins at lm393.
Remove R10, it's not needed.

Thanks Vitat, I have fixed it, I think!

Once more.
Put a p-n-p transistor and swap collector and emitter pins.

Thanks Vitat, I have fixed the schematic and built the circuit.
Will your firmware do anything if Yampp3 is not connected?
I tried connecting to my stereo's IP-bus, but M-CD is not available.  I am just trying to test it right now.
Also, what are the correct settings for the Fuse bits?

M-CD must be available without connecting yampp3.
Fuse bits for Mega8?

Yeah, Mega8 has fuse bits or option bits.  I know the one needs to be set for external oscillator, but I don't know what to do about the rest.  I wonder if that's why my HU doesn't recognize M-CD?

You don't read main site? http://www.vitat.spb.ru/eng/index.php?L1=ip-bus
You can found screenshot with fuse bits. http://www.vitat.spb.ru/files/ip-bus/lockbits&fuses.jpg

Sorry, I did find the image earlier and forgot to update my post, but those fuse settings don't seem to work and they kill the ISP.
Maybe I didn't translate them correctly?  I am using AVRStudio4 and the fuse settings look a little different.  What program did that screenshot come from?
You have CKSEL0, CKSEL1, CKSEL2, CKSEL3 = unchecked.  Is that same as CKSEL=[0000]?  SUT0 = checked, SUT1 = unchecked, is that same as SUT=[10]?  BOOTRST=unchecked, is that same as BOOTRST=0 or BOOTRST=1?  I think AVRStudio4 BOOTRST checked is same as BOOTRST=0.

Maybe it would be easier if I just use the same program as you used, but my programmer is an Atmel Dragon so the program I use must support it.

Can you tell me the hex values of the fuse bytes?

checked = programmed = "0"
In AVR, programmed = 0, unprogrammed = 1.

I used YAPP and I say it on main site too.

Ok, I see YAPP.  I can't use YAPP since it doesn't support Atmel Dragon.
I found a handy fuse calculator here:
Fuse Calculator (http://palmavr.sourceforge.net/cgi-bin/fc.cgi?P_PREV=ATmega8&P=ATmega8&V_LOW=2F&V_HIGH=89&M_LOW_0x3F=0x2F&M_LOW_0x40=0x00&M_LOW_0x80=0x00&M_HIGH_0x01=&M_HIGH_0x06=0x00&M_HIGH_0x08=&M_HIGH_0x10=0x00&M_HIGH_0x20=0x00&M_HIGH_0x40=0x00&M_HIGH_0x80=&B_BODLEVEL=P&B_BODEN=P&B_SPIEN=P&B_SUT0=P&B_CKOPT=P&B_BOOTSZ1=P&B_BOOTSZ0=P&O_BITS=Apply+fuse+bits)

I think I have the fuses set correctly, 0x2F & 0xC9.
Still no communication though.  I must have a hardware problem somewhere.  :(

Okay, I am now revisiting this project 10-months later!
Unfortunately, I was never able to get it to work.  I am almost certain the circuitry is assembled correctly, but I'm not sure.  I tried to diagnose the problem by myself, but I am lacking in any real electronics knowledge.

I took some measurements of various test points on my circuit with a scope, would somebody please take a look and tell me if anything looks wrong?

This is the schematic of my interface showing the test point locations. (http://i2.photobucket.com/albums/y15/GnatGoSplat/IPBus/LoggerSchema.gif)
TP1 - Atmega8 Pin 14 (http://i2.photobucket.com/albums/y15/GnatGoSplat/IPBus/tp1.jpg)
TP2 - 2SA733 Base (http://i2.photobucket.com/albums/y15/GnatGoSplat/IPBus/TP2.jpg)
TP3 - 2SA733 Collector (http://i2.photobucket.com/albums/y15/GnatGoSplat/IPBus/TP3.jpg)
TP4 - LM339 Pin 3 (http://i2.photobucket.com/albums/y15/GnatGoSplat/IPBus/TP4.jpg)
TP5 - LM339 Pin 1 (http://i2.photobucket.com/albums/y15/GnatGoSplat/IPBus/TP5.jpg)

IP Bus TTL signal I measured on an HA12240FP inside a CD-IB100 (http://i2.photobucket.com/albums/y15/GnatGoSplat/IPBus/ipbus_ttl_signal.jpg)

Link to the pics above (http://s2.photobucket.com/albums/y15/GnatGoSplat/IPBus/)

Any help will be greatly appreciated!

Scope pics make with connected HU?
Can you upload firmware with diagnostic on?

Yes, scope pics are with connected HU (Pioneer AVIC-D2).
What do you mean by upload firmware with diagnostics on?  The firmware was already uploaded.
Thanks.

Uncomment
#define LOG
and
#define ANSWER_A1
strings. And recompile firmware. Upload to emulator. Connect emulator to PC. Open any terminal programm.