Hiya,
Paypal sent, thank you.
My spark tester/distributor machine/8 plug pressure chamber also has a belt driven alternator on it so I can simulate that "noise". I hadn't looked at the schematic that close and you're right, if it's on the 5v side of the regulator that cap should be more than adequate. I'm going to build as the kit was designed, test and post any suggestions I see. When all that's done I gotta find a donor car
-Carl
Cool, if you have the capability I'd be interested to see how it handles the voltage spike when the battery gets disconnected. I'm not terribly interested in trying it on my 25 year old buggy for fear some pricey or difficult to replace box like the CCM gets zapped. Just a forewarning, I've seen some strange behavior with USB to RS232 adapters while firing coils on the test bench. Routing the coil power, spark leads and uart wiring away from each other seems to help. Luckily I've not seen anything like this in the vehicle.
The only thing I think I'd do differently with the PCB design at this point is omitting all the cylinder leds so the ADC input traces aren't cris-crossing some of the led driver traces. Although they were instrumental in initial troubleshooting efforts, there's almost no point in having the leds except on a test bench setup.
Well, actually make that two (or three) things. I forgot to put any silk screening around the ICP header and led ground jumpers to let the user know what's what. But the manufacturer had a limited time 20% discount and I rushed making the changes to get the order placed.
Planning to drive it to work the next couple days without logging anything, and hopefully be able to just enjoy the machine. I managed to scratch a couple year-old items off my honey-do list today, then vacuumed the footwells and washed her down (which makes it nearly certain there will be rain tomorrow). Then I gave my 16 year old nephew a demo he's been dropping hints about for at least a year. He got to smell tire and clutch smoke, there were large smiles on our faces, and we had a good talk in the process.
Speaking of, are the cylinder LEDs integral to the circuitry? If I omit them and their current-limiting resistors will the circuitry still run? Maybe jump the terminals?
Glad you and your newphew had fun. Always great to inspire the next generation to keep these things around!
1990 Corvette (Manual)
1994 Corvette (Automatic)
1995 Corvette (Manual)
None of the LEDs are required but I would recommend putting the power, status and spare output leds and resistors in. This way you can enable the INPUT_TEST conditional and be able to locate tdc and even sequence if you want. I have the spare output wired to a LED next to my cluster in the dash - I'm using it to drive a relay that controls power to my wideband controller. But with input test enabled I was able to put the trans in 4th and roll the engine over to test starts where the low-res beam was in one of the sequenced trigger slots (search the source for: detectSeqInverse()).
However, if you have a rev 1.1 board there are two jumpers - one for the three status leds and the other the coil indicators that disconnects their respective ground planes. This is equivalent to omitting the parts completely.
Oh yeah, having the status LEDs was going to happen, but I just wanted to see if the per-cylinder LEDs were integral to the actual firing of the coils on the rev1 board. Actually just looked at the PCB and saw that yeah, they're coming off of totally separate traces to the same pin, so they'd have zero effect if they were omitted. I do like the jumper arrangement on the 1.1 board though, that's neat!
1990 Corvette (Manual)
1994 Corvette (Automatic)
1995 Corvette (Manual)
I need some quick guide on the controller wiring.
Can I use the opti wiring as a B+ and ground for the controller.
So from engine harness I need to connect Hr, Lr, B+,G, Est and coolant.
Are the grounds on the board are common or on a separate paths.
G3,tx,rx,dtr are needed for logging only.
What is STS.
rev1.0 board.
Any hints are welcomed.
You should be able to hook into the opti wiring for all of those, yes. The grounds on the PCB are shared via a common ground plane.Originally Posted by kur4o
STS is the optional Status LED.
1990 Corvette (Manual)
1994 Corvette (Automatic)
1995 Corvette (Manual)
I would recommend connecting VIN and GND to the same circuits your going to be powering and grounding your coils with, definitely not the opti power because GM used such small gauge wire for this. I suggest this because the system voltage is measured between GND and VIN and we want a direct picture of the voltage the coils are seeing so dwell can be compensated accordingly.
G2 should be connected to the opti ground - think of this as a PCM signal ground reference.
More importantly for flashing firmware updates.
This allows for an externally wired LED that mirrors the yellow status indicator. O1 can be used similarly for the red OUT1 indicator, or whatever. As mentioned a few posts back the INPUT_TEST mode will show the low res opti input state with the OUT1 LED, and the high res on the STATUS LED.
I'll try to make time soon to write up a proper install guide. Documentation isn't really my favorite, and I frequently describe things in terms that only make sense to someone on the asperger's spectrum. So I may need help translating some ideas so they make sense to a wider audience.
So far everything's been good. I've put about 400 miles on this firmware version with nothing I can attribute to the controller save one missed start yesterday afternoon. I believe this may be a minor bug in sequence detection - I've had two instances (over the entire life of the project mind you) where it's refused to start immediately and feels like starting a distributor car with plug wires badly misplaced. I suspect this is an edge case happening only when the engine comes to rest at a particular location and the inverse sequence detection isn't just right. I'll try to log every start going forward but I may have to get more aggressive with trying to reproduce because I'm fairly certain it's only happened twice out of at least 600+ starts.
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