General question about product for a small project

#1

Hello all,
I want to know if this product could help me with a project. I bought a Pheonix Android radio for my 09 Infiniti G37 convertible. The radio was supposed to be plug and play but i found the 09 convertible model is different than the coupe and sedan of the same year. The radio works in the coupe and sedan. I did some research and found the convertible’s radio is different than the rest of the models. The convertible’s Bose amp is turned on thru the can bus. I would like to know if I could use the Macchina as a sniffer to find out which id and signal I need to send to turn on the Bose amp. Once I know the id and signal I need to send the signal to the amp to have it turn on with the Android radio. Would this tool work I dont want to waste my money and time if this is not the correct tool to figure out my problem. Any guidance would be greatly appreciated. I am new to this but have a little experience with industrial protocols such as ethernet IP, Profinet, Devicenet and more. I did not know there was a community like this doing such cool things until searching for an answer to my problem. I find this very interesting and would probably look for more thing I could do with this tool. Thanks in advance.

#2

Well since it is a BOSE system I will assume it is similar to the GM system. As an example. The '09 CTS Sedan I had was equipped with a base BOSE system. This 8 channel stereo worked much like an aftermarket radio. There is an amp turn on, the radio outputs are volume controlled and the amplifier reacts accordingly.

My 2012 CTS wagon has an upgraded 10 speaker BOSE system. This system uses SWCAN between the radio and the amplifier. This SWCAN not only turns the amplifier on and off but also sets the volume level and possibly other features of the amplifier. The feed from the radio to the amplifier stays the same level and the amplifier level changes.

I will guess the vehicle you have has a similar system to the 10 speaker BOSE system. I would also guess that the other versions have something similar to the 8 Speaker BOSE system for the CTS. While you COULD sniff and get it to work, you might be far better served by just bypassing the amp all together and using an after market amplifier. And then probably also using after market speakers… You MAY be able to get it to work but because of the volume and how it works you are likely going to have serious issues since your Android head unit is likely to not send anything out the CANBUS to control the volume and is adjusting the volume level of the outputs which wouldn’t be compatible with the amplifier.

You MAY be able to find a PAC adapter as well if it is compatible with the GM BOSE system.

#3

I am really not familiar with this subject as I only have used older car audio systems that are simply plugged in straight to speakers rather than using any amplifiers in the middle. I also don’t have any other expertise enough to truly give an advice on anything but I do have a feeling it could work after a lot of work. If the amplifiers are ran (adjusted) over signals through the CAN bus it should be visible to other devices plugged into the CAN bus as well so you should be able to sniff out the signals. First of all you want to find out as much as you can about the amplifier and the radio you are going to plug in.

Find out which messages are used to control the power and the volume and try to adjust those with your Macchina M2. Or search out first if that is the way to do it, for I don’t truly know the way it works. I assume that the signal sent by the radio to the amplifier must be at quite a constant level, ie. it doesn’t change the power between the amplifier and the radio (only the audio signal unamplified and unadjusted by volume setting) but the power between the amplifier and the speaker changes according to the volume set over CAN bus. In this case you may have to modify the new radio so that it won’t control the volume on the radio outputs but rather send a signal to M2 which then accordingly sends the message to the CAN bus. Also the output must be adjusted to work with the amplifier so that it won’t damage the amplifier by too much power. It will require calculations and tinkering with the hardware so it is in no way an easy task.

The question is more whether it is worth the time or not. It does require some knowledge on electronics and audio systems so it won’t be too easy. Also, sometimes the chips are built in the way the circuit can’t be easily modified so you have to bypass things in a hard way and it may be even harder to find a datasheet or anything of use.

Bypassing the amplifier may be the easiest way as redheadedrod said. You could tear it off and replace it with an amplifier suitable for your needs. Another way is to create a device that inputs the audio signals from the radio amplified, detects the volume from the power and sends that information over CAN bus and outputs the audio signal at a level the amplifier requires. It would be a new box somewhere in the car between the radio and the amplifier but it would do the trick.

#4

The issue with this is you will be injecting noise into the system. Much easier to just bypass the amplifier with a nice recent amplifier with the correct number of channels. You could start with using the factory speakers but realize they won’t live long unless you have the gains set low on the amp(s).

#5

Thanks for the info after reading the post I to think bypass the amp is the best route. I did not know the amp did so much and was not just a turn on and off thru the can. This tool seems to be something I can find other projects for so I will order one so this is not the last time you guys may hear from me. Thanks again.

#6

Yea, it allows the amplifier to give the best sound by keeping the radio amplifier simple and keeping the audio in the lines to the amplifier at a set level then letting the amplifier handle that stuff.

Rodney