Simple Decoder Series

For discussing and developing different RPM/Position decoders using our superior modular architecture! One thread per pattern, please.
Post Reply
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Simple Decoder Series

Post by Fred »

This decoder is for single edge distributor and batch injection use only, IE, VR, or of unknown angle teeth. If you know the angle, build a dual edge generic distributor decoder instead and get it included. The dual edge option is better, but you must know your tooth width, whereas with this, you don't. Either should be able to be used on hall/opto engines with appropriate physical timing, though.

This type of decoder ONLY supports distributor ignition and multi-shot batch injection with number of shots per engine cycle equal to the number of cylinders. This makes it unsuitable for fuel injection on larger cylinder counts, except with VERY low specific power, especially 12, 10, 8 due to additive dead time errors. To not do this would result in an engine that runs inconsistently between starts and has inconsistent AFR between cylinders at different loads and RPMs. If you don't like this limitation, get a better trigger type and use a better decoder! It's quite simple, really! (pun not intended, but noted) :-) You could also use MegaSquirt instead... though I wouldn't!

It's also worth noting that distributor setups with more than 4 cylinders either need extremely efficient short dwelling coils, or a very low redline to run effectively. This is the case for ALL distributor engines no matter how they are run. For more info, see this thread viewtopic.php?f=24&t=48

The 18 variations will be from 1 - 12 cylinders, (12,10,8,6,5,4,3,2,1) and rising/falling edge versions.

I'll post again when this is ready and included in the standard build.

Fred.
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
reanimotion
QFP80 - Contributor
Posts: 34
Joined: Sun Apr 14, 2013 8:50 am
Location: Australia

Re: Simple Decoder Series

Post by reanimotion »

Is this the current HallorOptical/VR-Distributor pair or something else entirely?
Steve
1981 Porsche 928S Bosch KE3-Jetronic Injection with FrankenCIS http://www.FrankenCIS.com
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: Simple Decoder Series

Post by Fred »

It refers to the VR Distributor decoder, however I've never bothered to make it happen, because it's nearly useless anyway and requires more other supporting code. OLD thread! :-D
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
reanimotion
QFP80 - Contributor
Posts: 34
Joined: Sun Apr 14, 2013 8:50 am
Location: Australia

Re: Simple Decoder Series

Post by reanimotion »

Fred wrote:OLD thread! :-D

One of many ;)
Steve
1981 Porsche 928S Bosch KE3-Jetronic Injection with FrankenCIS http://www.FrankenCIS.com
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: Simple Decoder Series

Post by Fred »

Indeed, there is a lot of value on this forum, my favourite being the wideband thread.
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
Post Reply