CanBox selfmade for Android STNAV

[ronald0001]

Hi
i am thinking about to make a own CanBox for Android Satnavs

Ok, i want to use my Raspberry Pi wich i have also in the car (but later can port script to an Arduino) and there i have connected High, Low, and Multimeadicanbus.
What i know is that the original CanBox communicate over serial with the Radio.
What i want is to decompile the apk wich is cummunicating with the box but where i can find it and is it possible to edit an apk file

Cuz the canbox not send the station names of radio...
also i want to enable the optical pdc of the radio and many more
also i want to hide the climacontroll panel behind the plate, so i have there place vor my display of the raspberry, and add the climacontrol to the radio (have it inside but at the moment only show the current settings and can not change temp and so on....
and also i am interessted if googlemapapi can be used to show directions and left km for next action in the ipc

i read many stuff on xda there is one guy who manage it to build own canbox for his mercedes
but he not tell how to work with the apl

maybe someone want to start this project with me

[DGAlexandru]

If it is Serial communication like RS232 then you can hook a RS232 to USB adapter (maybe also a TTL like MAX232 to have 3.3V to 12V) on that and sniff the traffic.
First with the RX of USB RS232 connected to one wire (GND also connected) then to the other one. If you connect to TX of CAN adapter, which is connected to RX of Android unit, you will get commands sent by adapter to Android; when you connect to RX of CAN adapter, which is connected to TX of Android, you will get commands sent by Android to that CAN adapter (CanBox).

If you connect also the TX of USB RS232 to the other line, you can also try to send commands to the RX device you are connected to.

There are plenty of Android APK decompiling tools, but if they obfuscated the code it will be harder to understand... and it would maybe be easier to write an Android App from scratch.

[Go4IT]

If i would do so, i first tried to understand the original protocol. For this i would sniff the communication between the canbox and the radio to get an understanding of how it works. Maybe you are able to find out some commands and their meanings, is it sent as cleartext commands, or like an AT-code or just bytes. Once identified such commands it may be easier to find the representation of it in the App-code?

[ronald0001]

If i would do so, i first tried to understand the original protocol. For this i would sniff the communication between the canbox and the radio to get an understanding of how it works. Maybe you are able to find out some commands and their meanings, is it sent as cleartext commands, or like an AT-code or just bytes. Once identified such commands it may be easier to find the representation of it in the App-code?

via seriel i know how it works...and box translate the serial messages int can id and data...also other way...my problem is to find the app on the device wich control/receive/send messages...this app must be modded to add also ms and hs can messages...

[ronald0001]

If it is Serial communication like RS232 then you can hook a RS232 to USB adapter (maybe also a TTL like MAX232 to have 3.3V to 12V) on that and sniff the traffic.
First with the RX of USB RS232 connected to one wire (GND also connected) then to the other one. If you connect to TX of CAN adapter, which is connected to RX of Android unit, you will get commands sent by adapter to Android; when you connect to RX of CAN adapter, which is connected to TX of Android, you will get commands sent by Android to that CAN adapter (CanBox).

If you connect also the TX of USB RS232 to the other line, you can also try to send commands to the RX device you are connected to.

There are plenty of Android APK decompiling tools, but if they obfuscated the code it will be harder to understand... and it would maybe be easier to write an Android App from scratch.

i do simular way...in my case the reaspberry py with usb ttl device working as translator between canbus and radio

[ronald0001]

when i have time i can upload some logs...
but at the moment i am full with work and jobs...so next 2 weeks not have realy time for it...