rusefi.com

... and just want to make something up?
Arduino compatible, two-channel low-impedance fuel injector driver based on LM1949 P&H driver; stack up to 6 of these and run a 12 cylinder engine?
(Ignition drivers sold separately)
... while trying to figure out what to do about the heat generated in the unit....

I seem to recall R1 and R2 will be your major heat generators. if you can get them to the edge of the board you could add a heat sink vertically.

When you say Arduino, I'm assuming you mean https://www.olimex.com/Products/Duino/STM32/OLIMEXINO-STM32/open-source-hardware which include automotive grade power supply and CAN. The problem is that it doesn't play nice with the pin count. If you have 8 fuel and 8 spark, you have gobbled up pretty much all your IO in the header stack. You need more IO for an Arduino for larger numbers of cyls. Or you need a mechanism for linking multiple units.

That Olimex board is nice, but with DC in minimum of 9v, and -25C to 85C temp range, probably not really well suited to automotive internal combustion engines- voltage in cold temps or 'old' battery could easily drop below 9v during cranking. Kind of cool, though, that it's an STM32 processor, so rusefi should be port-able to it, within reason.

Yes, R1 / R2 are the major heat generators since they are current sense shunt resistors. However, I wanted a short trace lengths to minimize any voltage drop. In retrospect, things should be placed differently since as rendered, the MOSFET is below board, and that resistor is on top so stacking would be impossible.

Maybe worth noting that one LM1949 could fire two high-Z injectors as a batch, meaning only 3 would be needed for a 12 cylinder engine, freeing up some of the DIO for ignition in wasted spark configuration.

But like I queried... do you ever get bored and do things just "because", with no real reason to do so?
I'd like to hear about some of the random musings others have had.

Have you seen Franenso

I have done some less constructive boredom prevention. Probably the biggest bang for the buck was when I ignited an exposition. It was heard by a friend inside a gas station 7 miles away. They were at the register, they asked what was that, then walked out side to looked around. When they returned from the beer run, they found a pile of us with out hearing, and suddenly understood what that noise was. I remember standing behind a metal tool box. After the bang, I looked down and noticed both my foot prints about 1 inch in-front of my foot. AKA the shock wave pushed me back an inch while I was standing. We are really lucky that no one got significantly hurt. I guess it's also good we made sure to have ear plugs on hand. If we didn't I'm sure we wouldn't have any hearing at all these days.

So I guess to answer the question, no I never get bored. I always find something to do. and with some planning I can make those things constructive.

Not exactly sure that is what I meant when asking the question, but hey...
... to the extreme he rocks the mic like a vandal....