Jump to content

Duty cycle measurement on Digital input


integrale8v

Recommended Posts

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

Link to comment
Share on other sites

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.   

Link to comment
Share on other sites

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?

Link to comment
Share on other sites

  • 3 months later...
  • 1 year later...
  • 5 months later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...