It’s been over two months since my last update, and I apologize for that.  As I knew would happen, the holidays took our family by storm an we were busy from early November through New Years.  As many of you know, I was trying to get the whole project done before Halloween for that reason.  Oh well, hobby projects always take the brunt of scheduling conflicts, and here we are.

I have worked out a few hours a week through January to spend on PMCv1 and we’ll see where that gets us.  First up was to pour through service manuals and extract connector information (for both 11pin and 20pin connectors), part numbers, and net names, and try to generate a spreadsheet that captures my findings.  I have that largely finished now, with the service manuals that I have received.  I cannot guarantee the list is 100% perfect, but I’ve been through it several times and haven’t found any errors (yet).

PMCv1 Availability List Updated

The PMCv1 Availability page has been updated (today) with my latest findings.  Many models are now listed in one of several categories, which I’ll describe below:

• Yes (3V, Tested) — this means the board runs on 3V (yay!), and has been tested to work properly..  Lowest risk category
• Yes (3V, Un-tested) — this means the board runs on 3V (yay!), but has not yet been tested.  I only have one Panasonic television, so cannot test all other models. However, as units are tested on customer sets and I receive feedback, I will move them to a “User Tested” category.
• Planned (5V) — this means that an adaptation will have to be made for the board to run on 5V (boo), but that service manual schematics seem to indicate that no additional changes or testing will be required.  When 5V support is complete, I will convert these to “Yes (5V, Un-tested).”
• Hopeful (5V) — this means that an adaptation will have to be made for the board to run on 5V (boo), and that there are other differences in the service manual schematics that give me reason to suspect more adaptations will be required.
• Don’t Know Yet — this means I have not yet been able to determine if support will be possible through the current PMCv1 module architecture, for reasons that vary model-to-model.

What’s Next

That’s a good question, thanks for asking.  With a decent sized list of TV models that are expected to work, the question becomes pragmatic.  I can go ahead and possibly build a small number of PMCv1 modules, see how they sell and perform, and if things go well then proceed with a custom design to support 5V models and investigate the “Hopeful” categories.  There are several other options available, but this one seems like the easiest to achieve with my limited resources.  There are some concessions that will have to be made however, such as no protection diode.  This simply means that I will need to provide orientation instructions, because if it’s plugged in backwards it might fry the module (because I’m using existing, not custom, parts).  I have so-far been unsuccessful in plugging the module in backwards, but I wouldn’t put it past a stubborn heavy hand to force it in the wrong way.

The other approach is to wait and go with a custom board (that I talked about in previous updates), of which I have two designs mostly complete.  These designs will include protection diodes, but will cost more and take more time.  Also it’s a much larger up-front investment on my part, which I’m not yet sure I can recover.

I am leaning towards the existing design (with no logging options, but with the “undo” switch that I have talked about before), because it’s simpler and costs less money to get started.  That way I can see how the module works with several different models and it will give me the time I need to determine whether or not there is enough interest to pursue a custom design and 5V model support.

That’s all for now.  Thanks for your time!
..dane