MS2/Extra (new) alpha code

[jsmcortina]

Just a heads up on what we've been working on within the new alpha code.

I've re-written the "every tooth" wheel decoder to allow it to handle uneven wheels yet retain the ability to schedule spark and dwell off every tooth.
This is a pretty major change and could easily have inadvertently broken things.

This uneven support has allowed me to add code so far for:
-trigger return dizzy
-oddfire dizzy e.g. chevy V6
-Neon
-36-1+1
-36-2-2-2
(EDIT to add these)
-Subaru 6/7
-Miata 99-00
-Webber-Marelli 4/ 1,2
-Mitsubishi 6g72
-generic 4/1 CAS
-generic 4/2 CAS (will not work until I get timing data)
-Renix 44-2-2
-Twin trigger (bike) mode odd and even fire (some sync issues)
-Suzuki Swift

(EDIT:) Also:
Fuel and spark table switching - hardware and software.

The above look reasonable in bench testing, but are not really ready for testing in a car/bike just yet.

When I feel the code is ready for some testing we'll be looking for some hardcore testers - preferably with a scope in the case where the decoding doesn't work out.
The sync and spark algorithms might work fine on the bench but an engine under cranking and transient conditions is another matter.

Technical details on what I'm doing:
The code defines an array of tooth sizes in degrees*10 and sets the required number of trigger teeth (one per spark event) on a tooth at least 10ATDC.
Custom sync code determines the position of the wheel, using both edges of the tooth is required.
The advance and dwell are calculated in the normal manner, but dwell is converted into degrees using the latest wheel speed in ticks per degree.

These spark and dwell angles are then converted into tooth counts by stepping through the tooth size array and the timers are setup to schedule an event after a certain tooth.

Although I'm on a bit of a roll at the moment, work is going to consume some time in the next month or so and development will slow again.

Attached is scope shot from Neon testing last night.

James

[mattd860]

Cool. This might be good news for the Audi 12 valve engine that runs the hitachi ecu. That engine uses a very weird crank position sensor that hasn't been able to be decoded by anybody other than the original hitachi ecu company. There is no chip or any other electrical upgrades for that engine so those guys are itching for anything short of welding a normal toothed wheel and trigger to the crank pulley.

[boost junkie]

Great work James! Cant wait to test this (hopefully in the near future).

[mpdsn]

I am also looking forward to testing this code. Please let us know when it will be available for download. I can be one of those hardcore testers you are looking for. I do have a scope and a PC-based Neon wheel encoder ready. In vehicle testing will also be possible once the code is ready for that stage as well.

Keep us informed. Thank you.

Marco

[pettaw]

Hello, any chance you could do something with the Renix 44-2-2 wheel?

[jsmcortina]

Please post the full timing data of it and I can take a look.

James

[pettaw]

44 tooth wheel, with 2 tooth space 180 degrees opposite each other, first tooth after the gap is at 90 degrees BTDC.

[jsmcortina]

What ignition are you trying to achieve? Single coil, wasted spark or coil on plug?

MS1/Extra will already cope with that wheel for a single coil.

Without a cam sensor there isn't enough information for wasted or COP.

James

[pettaw]

Sorry, yeah single coil going into a distributor. I'm running MS1extra at the moment, but am looking forward to the increased resolution and tunability of MS2.

[jsmcortina]

8.1degrees per tooth is very odd, but I've got some code appearing to work. However, just checking a manual I have it refers to "a double tooth" as well as a double missing, so I need scope traces or trigger logs to get it right.

James

[jsmcortina]

Cool. This might be good news for the Audi 12 valve engine that runs the hitachi ecu. That engine uses a very weird crank position sensor that hasn't been able to be decoded by anybody other than the original hitachi ecu company.

If you can find or create an accurate cam and crank timing diagram I'm game to try to decode it!

James

[pettaw]

There's no double tooth on my wheel at all, James, just 40 'normal' teeth with two sets of double gaps. I'm guessing that a double tooth might be for different models where the Renix will want to know whether its at 1TDC or BDC, but the Renix on my Volvo doesn't care, it just waits for the gap and then triggers afaik.

I don't have a scope but I have in the past managed to record the trace of the wheel as a wav file on my computer, do you want me to do that?

I agree that 8.18 degrees per tooth is weird

[jsmcortina]

I don't have a scope but I have in the past managed to record the trace of the wheel as a wav file on my computer, do you want me to do that?

Or grab an MS2 and see if the code works.

I hope to release this alpha code for first testing within a week. As the changes are major I will not be suprised if there are some bugs in there despite my scope testing.

James

[pettaw]

Haha sounds like a plan, I'll contact Bill.

[natesully]

The generic 4/2 is what I want for my Miata, right? I'll gladly test it in-car, but I don't have a scope (yet). Good work, the code is developing fast!

[jsmcortina]

For Miata - here's your change to contribute - please provide info like:
- what direction does it turn in
- what crank angles are the "edges" at

Ideally put some degree tape on the crank and draw out the pattern marking the angle of each edge.
From what KaPower posted we know the angular size of the slots, so mainly this is a case of determining where the pattern starts and the wheel direction.

James

[md95]

Dont know about figureing out degrees, but the DSM 4/2 CAS rotates clockwise(looking at the CAS "nub" that is driven by the cam). Engine rotation is clockwise looking at the timing belt.

Since the Miata uses the sam CAS(i belive), i would *assume it rotates in the same direction..the miata guys may want to verify though.

Also, the CAS is adjustable, so i dont know if degreing the crank would be accurate?(as far as trigger angles go anyway-dont know if this is what you mean/looking for)

Also, what is the major issue with decoding this wheel for MS2? Are you working for a "better" decoding algorithm than MS1 extra, or are you just trying to get it to "work" like MS1 extra? I'm just curious, as to what to expect from running the MS2 over MS1. If we are trying to improve the decoding of this wheel with MS2, then that would be great(even thought it works wonderfully with MS1 extra)

Dont know if this helps or not

Matt

[jsmcortina]

The 4/2 CAS decoder in MS2/Extra will use both edges of the "crank" teeth for improved accuracy and will do coil on plug, wasted spark or dizzy (if there is such a thing) by decoding the cam signal too.

However, someone needs to step up and draw a diagram. It is a pretty good deal - you spend maybe half an hour tops on a diagram and then I spend maybe four hours doing the code.

(EDIT:)
I asked about Suzuki Swift, then found this: "the Suzuki Swift GTi has a dizzy wheel, with 4 groups of 3 teeth (12 total) each group has crossing points at 91,61 and 6 deg BTDC. "
Those are crankshaft degrees aren't they?

Sounds easy enough.

James

[rb26dett]

James, is there CVS/SVN access to the alpha branch? or could you do me (and others?) a (semi) working snapshot? I want to wire up my board the new way, and i was looking to run some cables in from the car to my desk and try to get some rpm readings much later today, or tomorrow. i'll be scoping the signals and modding the board today at the very least. i'm very keen to be your guinea pig for this. all i need it to do is read rpm, and fire plugs and injectors, anything else is a bonus.

setup is 36-1 and single second trigger as mentioned in a couple of other places.

cheers,

fred.

[muythaibxr]

James will be posting a snapshot very soon... I'll be releasing v1.0.0 today, and then shortly after I believe he'll post an alpha for v2