Category electronics

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Yes, I know that’s not the most impressive photo, but that’s the completion of my work tonight. I ended up making a new and much better PCB with which to tie everything together, mounted the filter and resistor, installed the second grommet in the case, soldered on the previously made Aux In cable, added the power cable, hacked in a fuse for the power cable, and called it a night.

So, yeah. Now the only things left to do are tear into the dash again, finally assemble and bolt in the iPod holder, run the iPod dock cable through the base of the stuff pocket in the console (whoops, need to purchase another 7/16OD x 1/4ID grommet), add the ends to the power cable, plug both the power and aux in cables in, strap the project box to a support in the console, and close it all up. Then, provided things go the way I want, it should just work.

After that I’ll start looking into changing the firmware on the head unit to read IPOD instead of AUX, and I’ll probably start seriously looking more into the Honda Music Link Device. I’ve got a growing desire to document as much about it as I can. Pinouts, high res board photos, and if the board doesn’t have too many layers, I may even try to work up a schematic. Or maybe even read out the ROM. We’ll see…

UPDATE: Oh, I forgot to add this photo of the bottle of acid, namely ferric cloride in water. I had it sitting in a pyrex measuring cup for two days because I wasn’t sure what to do with it. It can’t come in contact with metal at all, so I was having a hard time finding a container for it. While I was at GFS unsuccessfully looking through their cleaning products for such a contain, it came to me that I should just use a 1L wide-mouth Aquafina bottle to hold it. So I did. It’s working out nicely. Now I can save the solution to use a few months from now.

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Okay, I did decide to post a shot of the PCB tonight. That’s it, in the project box I chose for making this. It seems like it’ll work out pretty good, even though I likely could have gone with a smaller box. Ah well…

That there is the PCB I made, and this is the solder side of it right after I finished cleaning it up. The etching isn’t perfect, but it meters out solidly. So, hopefully it’ll work.

The components installed there are the 1MΩ resistor to make the iPod pause when the power stops and a salvaged choke (I hope I’m calling that the right thing) to hopefully eliminate any extra noise in the +12v coming from the car.

So, that’s about that… I’m likely going to the auto show tomorrow, so maybe I’ll get back to things on Thursday. We’ll see how that goes. :)

Oh, and all the photos from today can be found starting here and on in (photo gallery retired). Yes, there are lots of the PCB. It was the first I made, so I wanted to document it.

Finished custom Aux In connector. (Click for more…)

Well, a bit more progress was made on the iPod connection for my car. Today I soldered up the Aux In connector, potted it in epoxy for strength, shrink tubed it, soldered a 3.5mm (1/8″) connector on the other end for testing purposes, and tested it out. And guess what? It works just as designed.

The connector fits into the factory connector perfectly, tells the Navigation Unit (head unit) that there is something connected to Aux In, and accepts audio in phase on the proper channels.

Also, while cutting the black TuneDok stem to fit, it seems that I squeezed everything so hard that it caused oil to be squeezed out of the vinyl. Wow.

So, yeah. Both the spacer and heads of the bolts are painted, and I’m just waiting for the aluminum plates to dry so I can photograph them. I did get this really nifty photo of wet paint on one of the aluminum washers which I think could do nicely as a flyer photo or something. Well, provided the flyer was printed fairly nicely.

Now all I need to do is order the rest of the parts I need. These should include a cast aluminum project box, PCB etching kit, tin coating kit, and a few other odds and ends which I need to finish everything up. I’ll go order those now, I think.

Connector for ‘Auxiliary Jack Assembly’ on Honda Wiring Harness
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Ahh, I think I finally figured out exactly how I would make the connector for inside the dashboard of my car for inputting audio into the connector which originally plugged into the rear of the Aux In connector on my dashboard.

What I ended up doing was taking a PCB salvaged from a 2x CD-R and an old CD-ROM drive controller and pulling the long pins off of the CD-R’s PCB and the plastic .100″ spacer from the CD-ROM controller. I then straightened the pins and assembled the pins into the connector, first bridging pins 1 and 2. (This indicated to the head unit on Honda cars that there is something connected to the auxiliary input.)

I then fit everything into a random (probably the VESA connector) header on an old video card and ensured that there is 3/8″ of pin hanging out the non-wiring side of the spacer. After getting everything aligned, I applied a bit of epoxy to the back (wire) side of the spacer to hold the pins in place.

So, tomorrow, likely after the epoxy has cured, I’m going to cannibalize another MIDI cable for it’s nicely made wire assembly, and I’ll use the red / white / green wires and connect them to the left / right / return (ground) pins on the newly made connector. Then I’m going to attempt to pot the entire solder/wire portion of assembly in epoxy. This will provide a nice bunch of strain relief along with ensuring that nothing in this connector shorts out.

Even though I only need three pins, I think I’ll use a DB9 connector for the other end, the one which will connect to the junction box. It’ll be shielded, easy to solder, unlikely to fall out (screws on the connector), and quite solid.

So, yeah… It’s shaping up nicely thus far. Now it’s bed time or something.

Some ideas…

– Find a way to safely / easily / reversibly remove the door on the aux audio connector (probably pin + spring friction fit) and use a right angle connector.

– Trace pinout on cable between Nav unit and Music Link adapter box.

– Identify pins used for power. Likely pins 9 and 10 of connector E ‘BLU (SAT ECU BUS (+))’ and ‘PNK (SAT ECU BUS (-))’. May also be pins 1 and 11, ‘BLU (+B GA-NET)’ and ‘BLK (GA-NET GND)’.

– Adapt one half of 08A31-0F1-000 (BUS HARN 2PORT) to provide power to iPod (hopefully is +12v, otherwise cancel idea) and use other half to Honda Music Link. Probably wire-wrap / solder two pins in connector and heat shrink for insulation. Harnesses are cheap and readily available.

– Mount Belkin TuneDok in left side of storage area in front of gear selector. Use threaded sleeve from center of cupholder cut out and braced with large (trimmed?) washer. Bolt through bottom of stoarge area.

– Buy Belkin Auto Kit (Black) from eBay to acquire dock connector cable.

– Small PCB in project box holding 1MΩ resistor (to emulate Belkin Auto Kit and pause on power off). Probably will also patch audio from dock cable to 3.5mm plug and power from wires leading from BUS HARN 2PORT to dock cable.

– Appears to be space in console in front of gear select to mount small project box. There is a medium sized structural tube to which it could be cable tied (with padding, similar to how Music Link box is mounted).

– RF chokes on all audio lines inside of project box, just to be sure.

End result should be all-black mounting hardware. No changes to any factory wiring. Audio fed through factory connector, power pulled from the same place as iPod charging power is currently acquired. Power to iPod should be nice, clean power, filtered by whatever filters the power in the head unit making for no noise.

Before doing all that, I need to take my vehicle in and get the resonating sound I’ve been hearing when the engine is running at 1400-1500 RPM checked out. I think this is a common problem. I also need to get my iPod taken care of at some point, because I think the disk in it may be dying.

Okay, end of rambling.