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'''Mazda Miata trigger''' I found that with 1.2.31 TDC_after_trigger had to be set at 9deg when strobing the engine. I strobed the car on #1 cylinder on 0,10,20,30 and 40 deg and it worked fine. It also drove fine when I did the initial tune. There is an exception which allow 0-10 deg TDC_after_trigger when using coil type trigger. I think that applies for this trigger as well and that is why it can be driven at all. The only thing I notice is a hickup when the car starts up, IIRC this happens on the cars where the 0-10deg setting has to be used. I'm afraid that something was not correct with the documentation I supplied for the trigger development. I took by scoping another car and made the trigger pattern below based on that car. I payed to much attention to the longgap/shortgap selection for The MiataNb in 1.2.32. The car now runs fine and is strobed: http://www.vems.hu/files/MembersPage/JorgenKarlsson/MiataNB/v3.3_u009005-A-2015.03.22-18.21.20_strobad_1.2.32.vemscfg. The config only works on 1.2.32 and up. ---- Thanks for implementing this trigger system quickly! -Jörgen '''Background''' The Mazda Miata is one of the most popular spec race cars in use in Sweden. One very successful combination is to put the 99-01 NB engine in the early 90's cars. The leading race car drivers here in Sweden wish to run with the stock trigger as they want the option to run the car on the stock engine management system if there is a problem. I am developing a plug and play harness for these cars and I would like us to look at the trigger to see if we can make this work reliably. '''Trigger system''' The crank and cam sensors are hall triggers on the 99-01 Miata NB engine. The teeth on the crank look like they are made for a VR trigger but it really is a Hall trigger. This is what I found when scoping the car. This should be sufficient for implementing the trigger. It could be a degree or two off here and there as it was taken with a scope on an idling car. As the crank trigger pattern is not symetric it's probably simplest to decode to a 4+1 trigger by counting and ignoring teeth. Possible pseudo code for the input filter: <code> Primtrig / Crank interrupt routine: if( secondarytriggercount ){ if( secondarytriggercount > 1 ){ if (primarytriggercount == 0){ initial sync found ...} primarytriggercount = 1; // tooth_wheel = .. } secondarytriggercount = 0;// Reset every crank pulse. } if (primarytriggercount == 0) return; // not in sync yet if( (primarytriggercount++) & 1 ){ // return if it was odd return(); // Return if it's the first tooth after cam sync () } //tooth at 50 deg found if this point is reached. primarytriggermagic(); ---- sectrig / cam interrupt routine: if (secondarytriggercount++ == 0) return(); // ignore single cam pulse // dual teeth cam sync pulse found if this point is reached. secondarytriggermagic(); </code> Note: '''this implementation depends on sectrig''' : Even if it has distributer (which I don't know), and same ignchannel configured for all 4 entries; it depends on working camsync, and will NOT limphome with broken sectrig. http://www.vems.hu/files/MembersPage/JorgenKarlsson/MiataNB/Miata99.png
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