Apple Carplay Technical Secret

Apple Carplay Technical Secret

There are very limited information about how apple carplay works. And why that the aftermarket car receiver cost that a lot of money by supporting the iphone carplay function. Is there any advanced chips inside that receiver which adjust the price tag? To discover the truth, I have invest $700 for a Pioneer unit from BestBuy, a used iPhone 6 that costs $500 dollars from Ebay. -That is how much you must spend minimum to be able to play with the carplay.

If you are reading this line, then you are the luck reader to know the secrete. Please do not tell anyone where did you find it, just keep it to yourself! -- This is a test of "how long you can keep a secrete". If you do not think you can do it, close this page IMMEDIATELY NOW.

To see the detailed USB traffic information during an iphone carplay initialization, I used an USB protocol analyser (Teledyne LeCory Advisor T3). Then I connect the port A of the analyzer to the iphone, and the port B of the analyzer to the Pioneer receiver. Here is what happened :

1. As soon as I plug the iphone on port A, the Pioneer is in host mode and enumerates the iphone and pulled the information from the iphone.

2. Then after 0.5 second, the Pioneer sends a USB packet to iphone to tell it to switch into carplay mode. Then the Pioneer itself stops sending information and switches to USB device mode.

3. When iphone received the carplay request, the iphone switches into host mode and enumerates the Pioneer.

4. The iphone pulls information from the Pioneer. If there is a carplay authentication chip in the Pioneer, the iphone start the carplay mode and sends the display screen to the Pioneer.

5. Conclusion:

In carplay, the car receiver only acts as display and touch pad of the iphone. All real functions are performed by iphone App.

Apple takes the full control of what you can do in carplay. Not the car company anymore.

All carplay should looks the same regardless the cars.