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XGATE PIT based bit bang fuel injection
Posted: Tue Mar 08, 2011 10:47 pm
by Fred
Sean and I have been discussing implementing this for our final injection solution. I thought we may as well document the dev process here. Hopefully the slack bastard actually replies to this one, unlike the loader one ;-)
So, lets cut to the chase!
We need three pieces of software for this:
- configure the timers and registers and data set for each event required
- turn pins on at specific times based on timer events and data set provided
- turn pins off at specific times based on timer events and data set provided
1) Sean is proposing that this run on the xgate, I like that idea. It will need some information passed to it, namely:
- pin number to fire (1 - 12)
- delay after input event to begin pulse (0 - 65535) in ticks
- duration of pulse (0 - 65535) in ticks
- ECT time stamp that the delay is based off (0 - 65535) absolute number - must handle roll over
This code will take the above info from registers populated from the s12 side in a function called by a decoder and setup the data and PIT registers to run the other two threads effectively.
2) fired by PIT timer - reads data set and switches pins ON as per setup done by 1)
3) fired by PIT timer - reads data set and switches pins OFF as per setup done by 1)
Sean, shoot holes in this! :-)
Fred.
Re: XGATE PIT based bit bang fuel injection
Posted: Tue Mar 08, 2011 10:57 pm
by Fred
My old PIT code did more or less this. The code for 1 can be found commented out in NipponDenso.c and the code for 2 and 3 can be found in igntionISR.c file. This code *almost* worked and worked for a short time perfectly until something went wrong. Something was a cumulative error that built up and then snowballed. I think.
Looking at this code could do one of two things:
A) poison your pure mind
B) help you see some ways of doing the job
It's up to you if you look at it or not :-)
Fred.
Re: XGATE PIT based bit bang fuel injection
Posted: Wed Mar 09, 2011 3:50 pm
by GartnerProspect
Fred wrote:This code *almost* worked and worked for a short time perfectly until something went wrong.
Ain't this always the truth mate!?!
Fred wrote:
Looking at this code could do one of two things:
A) poison your pure mind
B) help you see some ways of doing the job
It's up to you if you look at it or not
Fred.
I'm interested. I always wanted to be a poisoned programmer.
Re: XGATE PIT based bit bang fuel injection
Posted: Thu Mar 10, 2011 1:50 am
by Fred
I'd prefer people didn't look and purely came up with their own shlt by themselves. But, feel free if you're not developing it :-)
Fred.
Re: XGATE PIT based bit bang fuel injection
Posted: Thu Mar 10, 2011 9:18 pm
by SleepyKeys
I'll look after I get stuck or fail
In which case I will be able to combine info from both. Updating the debs right now.....
Re: XGATE PIT based bit bang fuel injection
Posted: Thu Mar 10, 2011 10:39 pm
by Fred
Sean0 wrote:I'll look after I get stuck or fail :) In which case I will be able to combine info from both. Updating the debs right now.....
Perfect!
Re: XGATE PIT based bit bang fuel injection
Posted: Thu Jul 21, 2011 10:02 am
by Fred
viewtopic.php?f=8&t=57&p=16068#p16068 enjoy!
Edit: As discussed, let me know what interface stuff you need, do your commits, push them, and rebase on top of any minor firmware work that I do as required. Sweet? :-)
Re: XGATE PIT based bit bang fuel injection
Posted: Thu Jul 21, 2011 1:56 pm
by SleepyKeys
So far so good no measurable jitter.
sorry on a mobile phone ill resize later
Re: XGATE PIT based bit bang fuel injection
Posted: Thu Jul 21, 2011 2:07 pm
by Fred
Wait, what is the Camaro super duper ECU doing on the bench, man??!! LOL :-)
How is that triggered? Is it some how relative to the decoder? Is it just done with clock delays? Is it using the PIT timers? Tell us more :-)
Fred.
Re: XGATE PIT based bit bang fuel injection
Posted: Thu Jul 21, 2011 8:40 pm
by SleepyKeys
I was anxious to get started . It is super though isn't it lol.
This was just some testing I was doing with clock delays. I wanted to see how strong things were. Jitter seems to be pretty much non existent. I'll continue to more on. Keep up the good work on the SM/Cheetah stuff.