GPIO questions | AEM
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andyftp
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Last seen: 1 month 2 weeks ago
Joined: 02/18/2016 - 17:47
GPIO questions

Hi!

Sorry to have so many questions recently.  Reading through the EMS-4 manual and the forums leaves me trying to spin my brain around how it all functions.

Say for example, I want to control the A/C clutch.

I would have an input I would like to use (for example GPIO5).  And for clutch ground use GPIO4

The A/C has an output of 12v to turn on the A/C relay.  I'll tap into the output of that relay for turn on request.

After setting Switch input GPIO 5 as above, do I have to do any configuration under GPIO5? 

I thought I saw in the forums that maximum input for GPIO is 5v.  If that's the case, do I use a voltage divider or a regulator to get that input down to 5v, or in this case is 12v ok?

 

Further question, say if I want to have GPIO4 to only allow ground under these conditions, can I do this and how?

 "Throttle < 95%"  &&  "200<Coolant Temp< 290" 

 

Thanks much!  And to add, I appreciate all the help so far!

AEM_NS
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Joined: 06/06/2014 - 09:31
Switch inputs were intended

Switch inputs were intended to be grounds and you're correct that the max voltage to a GPIO should be 5v. The label of "12v=On" is simply a logic descriptor stating that input high is on and input low is off. You can reduce the voltage down to 5v and input that or you can use a small relay triggered by 12v to send a ground to the GPIO.

The standard A/C config options include a setting for max TPS but unfortunately there isn't one for coolant temp.

andyftp
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Joined: 02/18/2016 - 17:47
Got it! Thanks

Got it! Thanks

Is there any config that needs to be done on GPIO 5 settings to make it work?

AEM_NS
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Last seen: 10 hours 52 min ago
Joined: 06/06/2014 - 09:31
Setting a/c switch input to

Setting a/c switch input to GPIO5 and the logic should be it.

andyftp
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Last seen: 1 month 2 weeks ago
Joined: 02/18/2016 - 17:47
Great thank you, as always!

Great thank you, as always!