by jsmcortina » Tue Mar 20, 2007 6:19 am
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
- Attachments
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- Neon mode under test
- Image002smaller.jpg (59.83 KiB) Viewed 600 times
Last edited by
jsmcortina on Sun Apr 08, 2007 5:02 pm, edited 5 times in total.