A friend of mine has a 2005 Porsche 911. It uses a MOST network, same my XKR for the audio signal between the head unit, amplifier, etc. He is replacing the head unit with an aftermarket one that has all the latest doodads.

We believe we have everything connected properly, but we aren’t getting audio iutvof the speakers.

The audio comes out of the head unit on RCA plugs. I verified by hooking these to a speaker that audio came out of these. These plug into an adapter box, that connects to the MOST connector that previously connected to the back of the OEM head unit. The MOST network then connects to the separate amplifier. We used bypass connectors to bypass the things like the CD player, and Nav DVD player that are no longer used.

BUT, we aren’t getting any sound out of the speakers. The converter box is getting voltage, but I’m suspecting maybe it is fubar. Does anyone know how to test the MOST fiber signal from the converter box to verify it is working?

Thanks…

BTW…it’s supposed to be plug & play. Looks pretty simple doesn’t it?

 

Well…we got it working. Instructions said to use bypass loops on the MOST network that goes into the Navigation DVD Unit, and the CD player…which we did. Just for yucks we removed the bypass loops and connected these units back up to the MOST network, turned it on & voila!!!! It works. It’s a very feature filled unit in a DIN configuration. I know the closed we can get with our Jaaaaags, is the Tesla one, which I don’t care for the look.

By the way, feel free to add to this thread, on methods to determine the Most is working…without spending a fortune.

 

Hello Jeff,

A modern double DIN head unit solution for MOST-bus JLR vehicles is just over the horizon.

Rhys Morgan, a UK based Industrial Automation Engineer, has been doing the hard work since 2020 or so.
See: PiMost | Hackaday.io
and Home - (Modern Day Mods).

also see: iDataLink Maestro replacement radio solutions Radio, Amplifier and Radar integration solutions | iDatalink Maestro

Rhys has been developing his own head unit and promises to keep it open source. So far, he has provided a tremendous education for us wannabe electronics engineers.

Neither Automotive Data Solutions nor after-market "Receiver" manufacturers currently support a JLR solution: Compatible Radios | iDatalink Maestro
However, certain FORD products closely resemble the JLR features (HVAC, heated/cooled seats and etc.) that ARE supported via Maestro Rr and Rr2.

If a MOST bus adapter is developed to pass the audio from the replacement head unit to the OEM audio amplifier, then the Maestro Rr/Rr2 solution will be just a matter of corrected CAN node/messages. (Quite doable.)

An alternative to a MOST-audio adapter may be to eliminate the use of the OEM audio amplifier and just use the replacement unit's audio output.

Short of a custom program for the ICM (Integrated Control-Entertainment Module), the CAN-MOST gateway, it may be necessary to keep unused MOST modules connected or emulate them to avoid a system error. (PS: I haven't yet looked at the possibility of deleting MOST modules via CCF.)
See: MOST Network - Lesson 2, attached.

A sample of the ICM was found to contain the Freescale (NPX) MAC7111VPV50, TJA1041T and Oasis FOS8104-2440 (for MOST).
We have the binary for the microcontroller from SDD but reverse engineering the assembly code (to delete superseded MOST modules) would require very specialized skills.

I am looking at the current Kenwood line-up: DNX997XR, DNX697 and DNX577S with iDataLink Rr. In addition to supplemental screens for HVAC, seats, door open, TPM & etc., a TorquePro like engine data screen is available.

 

Jeff, @XKDreams
The Freelander MOST document in the previous post describes a fault condition when modules are not responding (or bypassed). That would appear to be the case when you followed instructions and used the bypass loops.
What aftermarket head unit was used for the Porsche? Steering wheel controls work? Adapter?
What worked and what did not?

The iDataLink apparently generates additional screens for the aftermarket head unit and communicates them using IEEE 1394 (iLink, FireWire).
Steering wheel controls are converted from resistance values to data and input to the compatible head unit via a 3.5mm jack.
Sony has a head unit that can tame the steering wheel (SW) resistance ladder output directly using an integrated SW setup.
Another adapter for some (not ours) head unit replacements and steering wheel controls is PAC Audio.
A DIY project for Arduino is Atomic Cactus – Resistor Ladder Steering Wheel Control Interpreter Using Arduino

Having researched and said all that, my complaints with the JLR OEM unit are poor screen performance in daylight and outdated nav maps.
The audio quality is actually quite nice with HD, CD or Sirius. Forget audio quality when the top is down. Bluetooth phone and directories work well.
Android audio is simulated by Bovee. If I could update the TS for daylight use and replace the NAV/DVD unit, I'd be done.

best regards,
Bill

PS: I'm looking at Rhys Morgan's work, current Kenwood HUs, SW adapters, Jaguar XF 2012-15 OEM, Arduino projects and reverse engineering anything and everything. Collaborators welcome. If there were enough interest, ADS or PAC-Audio might be willing to edit some of their previous work to suit our cars.