CM5908/5907 Plug-n-Play Bluetooth upgrade board

[earthwormjim]

Is that an E36 radio in the background I see? Future project hint?

[Boggie1688]

Bump for pulse check

[bradnic]

Jay's busy working new revs of the board. I was fortunate enough to have a prototype board in my E30 for my trip to Asheville / The Vintage.

Installation is a 4/10 in difficulty, with one connector being a bit of a pain to get to. It's definitely self-installable by just about anyone.

the install design, especially the way Jay reuses 3 screw on brackets from the tape mechanism on the replacement board.

Everything works as advertised!
- Push volume button to access radio functions, again to switch back to BT (AM/FM/WB, switchable with the BAND button)
- Phone calls from the OEM head unit
- Pause/Resume/Next Track/Previous Track
- Siri directly from the OEM head unit

I can't begin to tell you how wonderful the experience is. This is going to be a must do upgrade, right up there with a remote key fob retrofit.

Three quirks to get used to.. one may be manageable via the board design

1) If you get a random bluetooth refuse to re-connect situation happening, delete the pairing and re-pair. You may need to power cycle the radio as well. I had one pairing issue like this in 30+ hours of use, within the first 4 hours or so after install. It worked flawlessly after that.

2) There's a semi loud beep and a flashing "CLN" indicator on the head unit every 15 hours of tape use. This is by design to remind you to insert a head cleaning cassette! Shocked me a bit the first time it went off. Pulled out the radio manual and sure enough there it is documented, "CLEAN (Maintenance) Program".


3) You'll end up using the BT/tape mode most of the time once you upgrade. Unless you've done an antenna switch mod that means your power antenna will be up needlessly for long periods of time. I used a fog light switch in the empty slot of my hvac panel (those of you with the fader knob will need to come up with some other switch mount point).

How the pairing setup looks on an iPhone


Paired, BT mode, not playing


Paired, BT mode, playing


FM


Weather band (always fun). Manual power antenna button on upper left


I can't wait for a future version of this unit with added full pre-out support. In the interim you need to use the BMW premium sound amp if you want any sort of volume out of the car.

[Chrisbike]

I want this so bad, glad to see it's coming to fruition! I installed a factory CM5908 just for this.

[bradnic]

One thing I neglected to mention that I was asked via PM..

The audio quality with Bluetooth is just amazing. Music sounds like a modern aftermarket head unit, and far superior to FM radio reception. Deeper bass, broader dynamic range and super clean sound.

Phone calls sound great too - as good as any of the 3 aftermarket head unit+amp combos I've used.

I do miss my trunk mounted tube subwoofer though. If and when we get a version of his kit with preouts I'm definitely switching to it

[jaysterling]

I've been heads down working on the project, so here's what I've got for updates.

- I launched a website: insideoutradios.com. It's more of a stub for the time being but it at least has an email list you can sign up for that I'll blast when they become available for sale. I'll be working on filling the site out more in the weeks to come.

- Sent Brad (bradnic) an early version of the board since he was going to The Vintage show. Thanks for the feedback and for reppin it at the show Brad!

- I got the 5th print of the board back late last week (geez, isn't it done yet?) and this one is looking like a winner. I assembled one and was able to validate everything is working on both the 5908 and 5907. I worked out the auto-detection of the model on boot and kept one LED on the board to serve as a fault indicator that will light if neither model is detected (which could happen if you aligned the flex wrong on the 5907)

Ran out of a few components to finish up the remaining boards, those should be here by the weekend. Then I have a few more RF shields to make up before I can get this first round out. I have a total of 6 of these boards I can assemble - 4 for the current set of beta testers, 1 for me, which leaves one unaccounted for. I'd really like to find someone to install it in a 5907 and give it some real-world usage and testing - PM me if that's the radio you'll be installing in and want this last beta board.

So this should be close to the final design now:


After too many hours of soldering - 1 complete and 3 almost complete units.

[stonea]

Man I'm getting excited about this now! I love the OEM and stealth look of it. I can't wait to get one!

Edit: Also signed up for the updates!

[bradnic]

- Sent Brad (bradnic) an early version of the board since he was going to The Vintage show. Thanks for the feedback and for reppin it at the show Brad!

my pleasure Jay. you've done something great here that the community needs to know about! thanks for the chance to experience the prototype. So pleased with the setup!

- I got the 5th print of the board back late last week (geez, isn't it done yet?) and this one is looking like a winner. I assembled one and was able to validate everything is working on both the 5908 and 5907. I worked out the auto-detection of the model on boot and kept one LED on the board to serve as a fault indicator that will light if neither model is detected (which could happen if you aligned the flex wrong on the 5907)

This is great news. What do you think of the possibility to detect the CLN alert and bypass it? Is it something you can do in the firmware or would there be wiring changes?

Also could you comment on the noise level on the last board with the RF shield in place? The old version I had is missing the shield of course, and with the engine off, in an enclosed space (garage) and very loud volume setting there was some high frequency noise. It was definitely not audible on the road at all, but the shield has basically eliminated it right? Can you confirm?

I have a total of 6 of these boards I can assemble - 4 for the current set of beta testers, 1 for me, which leaves one unaccounted for. I'd really like to find someone to install it in a 5907 and give it some real-world usage and testing - PM me if that's the radio you'll be installing in and want this last beta board.

Someone with a 5907 needs to jump on that! you will not regret your decision I promise you.

[Todd Black 88]

Yes, I will be wanting to put it into a cm5907/5905 myself. That's what my m3 came stock with.

[djjerme]

I have a CM5907 I could try it in as well, let me know which you want me to beta with.


Sent from my iPhone using Tapatalk

[James Crivellone]

Looking forward to ordering one

[jaysterling]

This is great news. What do you think of the possibility to detect the CLN alert and bypass it? Is it something you can do in the firmware or would there be wiring changes?

I haven't tried to reproduce and see what's going on but from what it says in the manual, I kinda doubt I can do anything about it. It doesn't sound like there's a way to dismiss the tone once it starts going. And there'd need to be some way the cassette deck itself could dismiss the tone. I can't imagine what the use case would have been for that.

I think this might be a minor inconvenience that we have to put up with for 0.01% of the time. It's a retro "feature" ;) Think of it like an accomplishment. Take a moment (err, 10 seconds) to reflect on the last 15 hours of whatever's been coming out of your speakers.

Another quirky reminder that we can't totally shake the cassette past is that you can still turn on the Dolby Noise Reduction EQ if you want it to sound like garbage.

Also could you comment on the noise level on the last board with the RF shield in place? The old version I had is missing the shield of course, and with the engine off, in an enclosed space (garage) and very loud volume setting there was some high frequency noise. It was definitely not audible on the road at all, but the shield has basically eliminated it right? Can you confirm?

Yep, the shield that I showed mounted in the last post basically kills it all, at least to the point where it's lost in the existing noise floor of the stereo. The final thing is luckily pretty simple in design and will just screw down to the board with an included screw+nut. I gotta start looking for a manufacturer on alibaba to make a bunch of them.

[Boggie1688]

Jay sent out the beta boards on Monday, and being that I'm a few miles from his location I had a sneaking suspicion that I'd get it the day after. I rushed home yesterday after work, and sitting in the mail box was the beta inside out board for the CM5908/CM5907.

The board is actually smaller than I imagined. Placement of the connectors are well positioned for the cables inside the CM5908, and all of the connectors are label for their according head unit model.

Jay is still working on instructions, but I'm an impatient person. I quickly ate dinner, and pulled the head unit from the car. There are a few screws to take the top cover off (5?), and 4 screws to remove the tape deck. I'm not sure if this is correct, but the lcd read out was hindering the removal of the tape deck, so the front face plate was removed, 3 screws and two plastic tabs need to be pressed. The screen can then be pulled out.

The one snag I came across was the ribbon cable. I didn't realize that the connector had a sleeve that had to be disconnect to release the ribbon. I struggled for 20 mins trying to figure out how I could pull on the ribbon without tearing it. I ended up using an allen key that ran the width of the cable and pulled slowly. It was only then the connect sleeve opened, and I realized that there was more to removing the cable that just pulling it. I even gave the inside out board a hard look, and never realized there was a sleeve.

After that, a little bit of jimmying the tape deck around and it came out nicely. A quick screw and nut to hold the shield and the new board went in without a hitch. You'll have to reuse 3 of the mounting stands that hold the tape deck to the head unit. There is an included cable that is used to highjack the volume knob. And I think that is about it.

Jay includes 3 screws, but I'm not sure what they are for. I ended up just reusing all the screws that came of the head unit.

So far, the head unit is working great! The bluetooth sound quality is much better than anything the stock head unit ever produced. I ran into an issue with skipping songs, but it was getting late, and I didn't have a chance to really play with it. Could be nothing.

The head unit hasn't be completely reassembled. I'm waiting for a mic to arrive before I close it back up and really run it through its paces.

All in all, the installation of the board should take an hour. It is super easy and straight forward. The board is a quality piece, and I'm honestly shocked that Jay soldered everything himself. I know how to use a soldering iron, but not with the level of expertise required to put all the components on the board. I think most of us will appreciate the fact that the board comes fully assembled.

Here is a quick photo:



I can snap more tonight if everyone would like.

[bradnic]

how cool - mine should be here today hopefully.
you put the RF shield in as well yes?

[Boggie1688]

how cool - mine should be here today hopefully.
you put the RF shield in as well yes?

Yep shield went on.

I really didn't test it much. I connect everything, made sure it turned on, made sure it paired, and made sure sound came out of the speakers.

I'm super impressed that Jay was able to reverse engineer the head unit, and make a board that would fit and hijack the controls. All of which is done at a fair price!

Personally I think there is a huge market to retrofit older headunits with newer technology. I cringe every time I see a older car with a newer head unit. I die inside...EVERY TIME.