DIY LTCC or similar system for LT1s

[spfautsch]

The separation of Ign on with Voltage sensing will simplify wiring and give some burned fuse indicator.

In what way? Why is a blown fuse indicator needed?

I guess there will be no sleep idle mode that can be used with ign on.
A reboot is mandatory when ign on is sensed.

It's not a "reboot". The bootloader jumps directly to the setup() routine when first powered on.

Again, I'm open to debate the merits of an always powered controller, but you're going to have to have a lot better arguments than what you've brought thus far.

The next idea I have is to make some smaller form factor board with smt components and integrate it within the pcm. Use spare pcm pins for coil output. We need only 8 of them. All the wiring will be to the pcm pins so there is no need for anything else. The pcm have 5v output already so there will be no need to add voltage regulator.

I hope you like the idea and give it a try or think about it.

I considered going to surface mount tech. The first thing you need to consider is the minimum quantity you need to commit to in order to have a SMT product manufactured by a third party at a cost that makes it feasible. Additionally, I'm turning 50 soon, and I needed bifocals four years ago. So it was a very short debate. I have no intention of doing anything like that. The through hole board could be reduced in size somewhat, but I fail to see a compelling reason. If it functions identically who cares if it's the size of a slice of cheese or the size of two postage stamps? And it doesn't require a reflow oven to assemble.

I honestly respect and appreciate your suggestions. They just don't align well with a do it yourself project in my opinion.