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Duty cycle measurement on Digital input


integrale8v
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Hi is it possible to add Duty cycle measurement on the Digital input?

I have a problem with controlling the AC on a BMW e39, the request signal is  a signal with changing duty to show what the AC/heater wants.

Page 14  here: https://www.slideshare.net/fajarisnanto/60087943-bmwe39integratedautomaticheatingandairconditioning

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Hi Integrale8v,

I just had another thought that might work. I admit its a bit of a long shot but I dont have a E39 handy to test... 

If you are not using flex fuel you might be able to set your AC request DI as Ethanol content sensor.  With a ECS, the fuel temperature is based on the received pulse width, so I suspect you may be able to see a change in the "Ethanol temp" parameter based on the AC request duty cycle.  You can then use a virtual aux with "ethanol temp <" & ethanol temp >" to drive the ac clutch.   

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Hi Integrale8v,

I just had another thought that might work. I admit its a bit of a long shot but I dont have a E39 handy to test... 

If you are not using flex fuel you might be able to set your AC request DI as Ethanol content sensor.  With a ECS, the fuel temperature is based on the received pulse width, so I suspect you may be able to see a change in the "Ethanol temp" parameter based on the AC request duty cycle.  You can then use a virtual aux with "ethanol temp <" & ethanol temp >" to drive the ac clutch.   

Hi.

 

I already tested that, and it just showed the same temp all the time (belive it was 139c) .  The signal is only 5hz so maybe out of the "range" of the ethanol sensor?

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