Code mod: inverting fastidle output

[msoultan]

I'm looking to make a slight modification such that fastidle turns on when it reaches the cutoff point, instead of turning it off.

Code: Select all

if(IdleCtl == 1)  {
	if(outpc.clt < flash4.FastIdle)
	    *pPTMpin[2] |= 0x04;             // turn on fast idle solenoid
	if(outpc.clt < flash4.FastIdle - flash4.IdleHyst)
	    *pPTMpin[2] |= 0x04;             // turn on fast idle solenoid
	else if(outpc.clt > flash4.FastIdle)
	    *pPTMpin[2] &= ~0x04;            // turn off fast idle solenoid
}

Looking at the above code, it would seem like all I need to do is switch around the '<' and '>' signs.

The only thing I didn't know is if I need to swap the '<' for the hysteresis.

Honestly, I don't know what that hysteresis code actually does. Assuming the fidle value is 160 and the hysteresis value is 5 a temperature of 159 will turn it on and a temperature of 160 will turn it off. If it hovers up and down around there, it's still going to turn on and off.. I don't get it.. or I'm looking at it wrong?

Thanks!
Mike

[racingmini_mtl]

No wonder you don't get it: the code is wrong. The hysteresis is not really implemented with the code above. The first 'if' that turns on the fast idle solenoid should be removed:

Code: Select all

if(IdleCtl == 1)  {
   if(outpc.clt < flash4.FastIdle - flash4.IdleHyst)
       *pPTMpin[2] |= 0x04;             // turn on fast idle solenoid<br>
   else if(outpc.clt > flash4.FastIdle)
       *pPTMpin[2] &= ~0x04;            // turn off fast idle solenoid
}

So now if you want to invert the behaviour, you can just switch the '<' and '>' signs around as you proposed.

Cheers,
Jean

[msoultan]

haha.. that had me so confused! Thanks for the help! I posted a message on the MSEFI forums as well letting them know about the error.

Thanks!
Mike

[cmcook]

Can't you just turn FIDLE off and then set it in Output Ports? I am using the FIDLE output to switch my fan relay on when above a set temperature. No need to fiddle with code.....

[msoultan]

Can't you just turn FIDLE off and then set it in Output Ports? I am using the FIDLE output to switch my fan relay on when above a set temperature. No need to fiddle with code.....

thank you so much for that suggestion! I've never played with the Output Ports before. Makes life much easier!

Thanks!
Mike