2nd Build - Fan running 100%


 
On the continuity checks - I checked 1-9 as described (several times), those all were as expected per the table.

Not sure if this is important -
since you pointed out Q1 would have a leg that makes continuity with #4 (as Ralph pointed out on his diagram)
at some point I was touching #4 on the P-MOSFET and randomly checking continuity to other points and made continuity with GND on IC1.
Checked it several times and started typing this note.

When I went back and checked it again, it DIDN'T make continuity.
I'm guessing that in randomly checking continuity I caused the P-MOSFET to change states?

Thanks for the help Bryan and Ralph!!
 
Very interesting development - after checking everything, I reassembled the HM and plugged it in.
It would be discovered but I couldn't access the GUI
Tried power cycling it a couple times to no avail.
Plugged in a monitor and a LAN connection - nothing, screen dark.'
Did a reset off the LCD, same result
Hmm.
Took it all apart, plugged in a USB power supply to just the RPi - came up fine.
Reimaged the SD card, edited it for WLAN and reassembled it all.

It came up fine - accessed GUI, plugged in the probes, everything is registering correctly.

Set it to pulse mode, plugged in the fan - and VOILA, it WORKED?!?!

It has been going for over an hour - I change the PIT temp periodically as the room temp changes and the fan cycles on/off exactly as it should.

Weird.
 
Ran 24 hours, no issues. I powered it down, installed it into the case and plugged it back in, came right back up no issues.
I'm completely baffled, but, it's a good kind of baffled :)

Thanks Ralph and Bryan for all your help!!!!
 
Yeah I am completely baffled as to how it could be a software problem but magic is magic so I am glad it is all up and running!
 
Honestly it couldn't be a software problem because he measured PIN 5 on the ATMega and it swept from 0V to 3.3v, that says logic is working...
I can only guess that perhaps there was a ball of solder somewhere that fell off, or a bad solder joint that flexed and started making contact.
 
It can and very well be a programming problem. I have seen similar before. It happens when the atmega gets a bad data when programmed
 
I agree that it COULD be a programming issue, I've seen that before as well...but as I was pointing out, he measured the output voltage on the BLOW pin of the ATMega and it indeed went down to 0, which is the voltage that should turn the blower off (but the blower remained on)... Therefore, it can not be a programming issue, as the logic was resulting in the proper voltage coming from the ATMega.
 
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