new HM build issue


 
S

Steven_B

New member
I am working on my first HM4.2 and am having a startup issue. I have no blower activity in auto mode. I can go to manual mode and move setting from 0 to 100% on display with no blower change. With a leg lifted out of the socket on ATMega pin 5, I get no voltage change. It is always 0 Volts. I have 3.3V on pin 7 and display is working fine.

The fan configuration settings from OpenWrt should still be the default settings:

Fan output: Voltage
Min: 0%
Max:100%
Startup Max: 100%

Blower does work with direct connection to 12V. I am not real sure where to look next. My guess is that there is something I need to do with a configuration setting. Any ideas?
 
That's really odd, you should see the voltage on pin5 ramp up and down with the HM output %, and with the leg lifted there is nothing to drag it down...
Maybe flash the AVR again? Just drawing straws, cause if its working the ATMega has power and ground and should function, so maybe something went south while flashing?
 
I reflashed the AVR and then the Pi and still no joy. The only other wonky thing I noticed was that my power adapter was a little high at over 16 volts. It regulates down to 5 and 3.3 just fine. My next guess is a bad ATmega?
 
I just lost my post and don't have the heart to retype it.

Thank you Ralph for the support. I had some success using another power supply that was noisy and underpowered. All my probing and reseating things may have fixed a loose connection or short or something. I did reflow the ATMega and rPi socket as suggested.

I am back on the original power supply and everything seems pretty rock solid right now.
 
Nice! My first ever HM build had a rocky start, ATMega didn't flash right, so I learned that from experience. Glad to hear you got it going...
 
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