HeaterMeter Hardware v4.3.3 and v4.3.4

Bryan Mayland

TVWBB Honor Circle
Oh wowie, actually the extra voltage readings are very helpful. You've got some krazy voltages going on there. The key indicator I am seeing though is 3.3V at AVC but only 2.46V or as low as 2.06V on VCC and RST. I'm actually shocked that the AVR is running at all, since it isn't officially rated to run at 16MHz under like 3.5V. I think it is being backfed through the analog power input side and the trace that feeds from the 3.3V regulator, through Q5, to VCC is busted.

Let's try this. Take a small bit of wire and solder it from the + side of the 100uF/10V capacitor between the 3.3V regulator and the ATmega to the VCC pin on the ATmega. Either that or just straight across from AVC to VCC, whichever you find easier to do. At that point hopefully you'll get 3.3V on VCC, RST. If that checks out, check SVO for ~0.290V at 0% output. If we can get that, we can fix the rest.
 

RobMorey

New member
Oh wowie, actually the extra voltage readings are very helpful. You've got some krazy voltages going on there. The key indicator I am seeing though is 3.3V at AVC but only 2.46V or as low as 2.06V on VCC and RST. I'm actually shocked that the AVR is running at all, since it isn't officially rated to run at 16MHz under like 3.5V. I think it is being backfed through the analog power input side and the trace that feeds from the 3.3V regulator, through Q5, to VCC is busted.

Let's try this. Take a small bit of wire and solder it from the + side of the 100uF/10V capacitor between the 3.3V regulator and the ATmega to the VCC pin on the ATmega. Either that or just straight across from AVC to VCC, whichever you find easier to do. At that point hopefully you'll get 3.3V on VCC, RST. If that checks out, check SVO for ~0.290V at 0% output. If we can get that, we can fix the rest.
The VCC is now at 3.3V, but RST only moved up to 2.78V, SVO = 0.16V. Also, the pin on the same side as SVO next to it (Pin3?) is now 0.78V (slightly higher than 0.56V prior), and LE1 is now only 2.3mV
 

Bryan Mayland

TVWBB Honor Circle
Well that's not exactly the stellar improvement I'd hoped for, but you know what? I just learned something. The RST is actually 2.78V. I just assumed that the 10K pullup was just a pullup, but it actually draws more current than I expected. I have 2.8V on my RST pin so that sounds good. I think you're in business, even though the SVO is a little low.

Now put Q5 back in place. You're going to need to solder new connections to it since the pads are damaged. I think your middle one is OK but the other two sound like the are kaput based on your previous measurements. This is it! If this works, it works. If it doesn't, then I'm not sure where to go from here.
servowires.png
 

RobMorey

New member
Well that's not exactly the stellar improvement I'd hoped for, but you know what? I just learned something. The RST is actually 2.78V. I just assumed that the 10K pullup was just a pullup, but it actually draws more current than I expected. I have 2.8V on my RST pin so that sounds good. I think you're in business, even though the SVO is a little low.

Now put Q5 back in place. You're going to need to solder new connections to it since the pads are damaged. I think your middle one is OK but the other two sound like the are kaput based on your previous measurements. This is it! If this works, it works. If it doesn't, then I'm not sure where to go from here.
View attachment 1781
Shazam! Thanks Bryan I think that’s got it....need to do some adjustments on the damper to get it to fully close, but I think that’s a minor task. Appreciate all the help
 

Bryan Mayland

TVWBB Honor Circle
Heck yeah, we did it! Thanks for sticking with it and being such a great set of eyes on your board. Always makes me happy when we can solve a problem like this.

The open and closed positions you just need to edit the "Servo pulse duration" values in the webui and you're good to go.
 

RobMorey

New member
Hi All, I can’t seem to locate the how to create a adapter plate for a pit boss k24? Any help would be appreciated? FYI, I’d rather diy then purchase from bbq guru;)
 

Bryan Mayland

TVWBB Honor Circle
Hi All, I can’t seem to locate the how to create a adapter plate for a pit boss k24? Any help would be appreciated? FYI, I’d rather diy then purchase from bbq guru;)
It is probably the same as all the other ceramic grills. Just get a piece of sheet metal from the hardware store that's big enough to cover the vertical height of the vent, cut a rectangle out of it, then cut a hole in the center and put a 1" NPT nipple in it and secure it with a nut (the EMT conduit ones from the electrical section work really well). The dampers have a 1" NPT adapter that you just screw the other side in. Total cost is gonna be about 5 bucks.

For specific questions like these you'd probably get more views / response if it were its own thread and then it could also more easily found instead of burying it in this generic thread.
 

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