Proper wiring for HM Case with Switch.


 
Uh, well, the black CAT5 jack on the HM board is to connect the blower and servo (and RDTC or whatever you use the 4 spare wires for), it is not a LAN port to connect to a network.

If you want to connect the HM to the network you need to use WIFI or the SILVER LAN PORT on the rPi.
 
RalphTrimble said:
Uh, well, the black CAT5 jack on the HM board is to connect the blower and servo (and RDTC or whatever you use the 4 spare wires for), it is not a LAN port to connect to a network.

If you want to connect the HM to the network you need to use WIFI or the SILVER LAN PORT on the rPi.
Click to expand...

Doh! Yes. I'm an idiot.

So I mated the RPi and connected the cat5 as I should have before. No HM is found when I go to the registration screen. I also scrolled through the LCD menu and noticed my Pit probe had a 100 degree offset then the next probe was listed like this, then a no name probe, then another probe listed as in this picture.

https://drive.google.com/file/d/0BzSBmZGY0VqYRkhUbFdnMkN6c2s/view?usp=sharing
 
Take your SD card or actually just get another SD card that hasn't had the software on it and install the heatermeter software and redo the heatermeter. If it does not except the new software then you may have a problem with the atmega

This heatermeter has been through everything possible and it somehow keeps wanting to work, lol.
 
I've plugged the HM CAT5 jack into my laptop by mistake and did no damage to the laptop or HM....

Hard to really tell you what is right or wrong at this point after all you've put that board through, and not having it in front of me. I would disconnect the power from the HM, remove the rPi, remove the ATMega from its socket, then reseat the ATMega, power the HM from 12VDC, hopefully get NO PIT PROBE on the screen and able to navigate menu's with the button.

If you don't get back to normal function with the HM board at that point you need to troubleshoot... Measure 12v,5V, 3.3v. Could be bad solder on the ATMega, shift register or LCD header.... Could be the program stored in the ATMega got jacked up from your power surge, and perhaps re-flashing it will fix it up.
 
I reinstalled the software on the card and plugged it back in. I also reseated the ATMEGA. I was still seeing those crazy offsets, but was able to reset the configuration on the LCD, and that cured it.

From there, I was then able to get into the GUI on my laptop and changed the probe type to TC. When I went back and started plugging in the RDTC to check the TC on that end, I realized the 100K resistor behind the TC on the HM wiggled off. I'll have to get that resoldered before figuring anything else out at this point.

I know most of this has been my own doing, but can I at least say I win the prize for most HM build problems?
 
Glad you were able to get reset and connected, that is encouraging... Perhaps when you get the 100K resistor back in place your TC will work again...
 
Got the 100K resistor back in place and saw all of the food probes were back running. The pulled up end of the 100K was still connected to pin7 of the cat5 jack. So I finished wiring that cat5 jack so that the RDTC would be good to go. The food probes on the RDTC were working great too!

I then plugged in the TC probe on the RDTC and it said no pit probe. As I inspected the board, I noticed the small 8 pin component on the solder side of the RDTC had a tiny solder blob causing a short on one side. I tried wicking it and sucking it but it wouldn't come out. I then heated it up with a hot air gun and pulled off the whole component. I was able to clean off all of the pins. I resoldered it to the board, but I had the same issue where there were 2 pins with a blob in the middle. I was using just a tiny dot of paste.

After plugging in the TC probe again to see if there was a reading, I went to unplug it and ripped off the white 3 prong component with the dial. Looks like the metal trace on one of the 2 legged sides came with it. I suck.

I haven't wired the 100K resistor back to the empty hole on my HM board behind the TC to see if my HM TC amp is operating, but I doubt it is.

What are my options with fixing the RDTC board? I'm kind of at the point that I feel like I should ask if someone can try to salvage/finish my build for me, because at this rate, I won't have anything left if I keep breaking things.
 
Being honest with you, seeing your solder work on the HM board I wouldn't encourage you to attempt to solder up a RDTC board. SMD soldering is way harder and more sensitive to over heating than through hole components. I would offer to fix the RDTC board but with traces ripped off and you having removed the TC amp IC and resoldered it I fear that could be an uphill battle, and I am not having as much free time lately to take on projects like this. You probably would have been better off having John Bostwick build the RDTC for you in the first place, SMD soldering is not really a job for a novice. That said, the white box thing is the REF offset adjustment and is not required really, you can solder over the offset jumper and run the board without that part. (if you can manage to get the chip soldered on cleanly) Perhaps post a pic of the RDTC board as it sits so we can get an idea how close to working it may or may not be....
I would encourage you to reconnect the TC amp on the HM board, which was already soldered up when you bought the board, I think that is your best chance of getting your TC up and running at this point.
 
RalphTrimble said:
Being honest with you, seeing your solder work on the HM board I wouldn't encourage you to attempt to solder up a RDTC board. SMD soldering is way harder and more sensitive to over heating than through hole components. I would offer to fix the RDTC board but with traces ripped off and you having removed the TC amp IC and resoldered it I fear that could be an uphill battle, and I am not having as much free time lately to take on projects like this. You probably would have been better off having John Bostwick build the RDTC for you in the first place, SMD soldering is not really a job for a novice. That said, the white box thing is the REF offset adjustment and is not required really, you can solder over the offset jumper and run the board without that part. (if you can manage to get the chip soldered on cleanly) Perhaps post a pic of the RDTC board as it sits so we can get an idea how close to working it may or may not be....
I would encourage you to reconnect the TC amp on the HM board, which was already soldered up when you bought the board, I think that is your best chance of getting your TC up and running at this point.
Click to expand...

Thanks, Ralph. I will work on reconnecting the TC amp on the HM board tonight. I actually soldered that up myself originally. Maybe I was lucky mixed with a healthy dose of naivety, but aside from finding the short on that mini IC on the RDTC, I thought the SMD soldering was much easier/cleaner than through hole soldering. I can see with something that small though that I don't have the surgical touch needed here.

I'll post a pic tonight after I get as far as I can. With the REF offset adjustment component removed at this time, I might take another crack at cleaning/resoldering the amp IC that is shorted. If I'm still unsuccessful and there isn't anything you would advise me to keep at it with, I'll likely throw in the towel and post a request to help finish my build.
 
Solder wick dipped in flux is the best way to clean up the solder on the SMD IC legs... Keep in mind that the two pins at the TC amp output (5 & 6) are bridged anyways, so you don't need to clear a solder bridge there between those two legs if there is one (the corner two pins where the output trace goes over to the standard probe leg). And on the other side of the chip the center two legs (2 & 3) can be bridged if you are not using the REF offset circuit. So that's two places on the TC IC that you do not have to worry about a solder bridge...

I was under the impression that your had purchased the HM board with the SMD TC parts already soldered on, so I was assuming that was a known good TC amp, I guess that was a bad assumption... If you want to post close ups of the TC section of your HM and RDTC board perhaps someone could spot your issue for you...
 
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I'm not throwing in the towel.....yet!!

I reconnected the TC amp on the HM and it operated as it should, aside from being high and oscillating within 3-4 degrees, but it was doing that before, after I had calibrated the offset using a pot of boiling water I was offsetting -10 degrees. The oscillation I was waiting to ask about, because I had read there is some ac line filter that can be used to smooth that out if it is from my power source.

Anyway, I then went back to the RDTC and used some flux on the solder wick and it looked and felt like I got the solder bridge. Here are some before and after pics. I then plugged everything in and when the TC probe was unplugged, the LCD was reading either no pit probe, or 648 degrees, occasionally spiking to 740-750. With the probe plugged in, it was a steady 820 degrees. No, I do not live in a pizza oven. Any thoughts?

TC Amp on HM working: https://drive.google.com/file/d/0BzSBmZGY0VqYTEhYM25taldBYWM/view?usp=sharing
Before wicking RDTC Amp: https://drive.google.com/file/d/0BzSBmZGY0VqYRzdhR1dZWUdIdjA/view?usp=sharing
After wicking RDTC Amp: https://drive.google.com/file/d/0BzSBmZGY0VqYcXFENE5PcUk1Rmc/view?usp=sharing
 
The RDTc board doesn't look too bad there actually, good work! You see the two pads there next to where it says REFG? Make a solder bridge across those two pads, that defeats the REF offset circuit.
 
RalphTrimble said:
The RDTc board doesn't look too bad there actually, good work! You see the two pads there next to where it says REFG? Make a solder bridge across those two pads, that defeats the REF offset circuit.
Click to expand...

Thanks!

So, I bridged those pads and I'm not sure it solved anything. I took better notes this time with the readings as I plugged/unplugged.

-With the RDTC with the probe inserted connected to the HM, I powered up and it registered 807.
-I unplugged the Cat5 from the RDTC and it showed no pit probe
-I replugged the Cat5 to the RDTC and it still showed no pit probe
-I removed the TC probe and it showed 650
-I reinserted the probe and it showed 807
-I removed the Cat5 from the HM and it went up steadily from 807 (I think based on the current wiring this is expected)
-I unplugged and then replugged 12V which started the reading at 280 and went steadily up from there
-I replugged the cat5 from RDTC with the Probe inserted into the HM and got no pit probe
-unplugged/replugged 12V gave a reading of 804
-removed the probe and it dropped to 650
-unplugged/replugged 12V showed no pit probe
-added probe, back to 807

Through all of this, I spot checked the food probe readings and they were reading correctly. I tried squeezing my TC probe to elicit a reaction of some sorts when it was plugged in, but there was no reaction.

One variable that may or may not matter, the TC jack I ordered for my RDTC came with one of the pins bent more than 90 degrees in the bag. As I bent it back, it broke off. I soldered a thick cut wire from a previously installed component to the remaining half of that side of the plug. I checked for continuity at the solder joint on the solder side of the board and at the top of the plug on the copper that goes into the plastic and it passed fine.

If the TC amp on the RDTC is still a mystery in my case, I don't know that I TRULY need it. I could likely get by just fine with the 2 food probes, using one as a pit probe, right? I also have spare food probe jacks that I could use in place of the TC if I really wanted to use 3 probes off the RDTC. I know I couldn't do high heat for pizza with a thermistor probe, but if its just 10 minutes a crack for those, I can always bring my HM outside and use the TC on the HM if I wanted to see that in action.

I'm done for tonight. Any thoughts?
 
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As for the TC behavior, if you power the HM without a TC amp connected to the HM (Probe 0) the HM will generally register temps that just rise steadily upward, which you have observed. As for troubleshooting the RDTC, you can first try measuring the input and output of the 3.3v regulator there, look for 5v input and 3v output (and check the ground too for continuity to ground on the HM board). It almost sounds like you are getting some REF offset, but with the REF Offset pin shorted to the Gnd pin next to it (the center two pins on the opposite side of where the output pin is) your REF Offset should be GND (eliminated) that said, IDK what it will do with the OP Amp IC (the larger one that is on the other side of the board) still soldered to the board with the potentiometer ripped off...

You are right, you can either install a 3rd standard food probe on the RDTC and use it as a standard pit probe, or you can disable Probe 0 in the HM config and use the first food probe as the pit probe.
 
Everything checked out with the 3.3V regulator on the RDTC. So I kept on troubleshooting.

I then figured it had to be the TC amp IC. So I checked each pin as carefully as I could for shorts. I then realized that one side of the chip was not really joined at all. So I then used the wick dipped in flux method to heat the other side and pull it off. I then removed all of the solder on those pads and cleaned all the flux residue off. I then repasted the pads and pulled out my big 'ole heat gun to reattach that IC for the 3rd time.

After letting it cool a bit, I plugged everything back in and.....IT WORKED!!!!!!!

The TC was registering about 12 degrees hot. The TC on my HM was about 10 degrees hot, so I should be fine with an average offset for both. It also was oscillating within 4 degrees just like my HM TC. There is an AC line filter that corrects that on a version of the software, right?

Before I move on here, I would like to ask about reconnecting the potentiometer. With the top right trace gone, would I wire that directly to the closest end of the 1M resistor, or some place else?

https://drive.google.com/file/d/0BzSBmZGY0VqYcXFENE5PcUk1Rmc/view?usp=sharing

Thanks for all the help here!!
 
Yes, there is an AC Line filter function in the software on the Config page... Not sure if it is in the release version but I know it is in the snapshot version that I am running (in the PID section)

On the potentiomter on the RDTC, the trace from the missing pad goes over to the 1M resistor right there, so a jumper wire would be easy to put in place. HOWEVER, the center two pins mentioned in my previous post can not be shorted together if you plan to use the REF Offset, and you would need to remove the solder bridge across the REFG pads as well.
 
RalphTrimble said:
Yes, there is an AC Line filter function in the software on the Config page... Not sure if it is in the release version but I know it is in the snapshot version that I am running (in the PID section)

On the potentiomter on the RDTC, the trace from the missing pad goes over to the 1M resistor right there, so a jumper wire would be easy to put in place. HOWEVER, the center two pins mentioned in my previous post can not be shorted together if you plan to use the REF Offset, and you would need to remove the solder bridge across the REFG pads as well.
Click to expand...

Got it, thanks Ralph!

To get back to the thread topic now that I fixed my bugs, since I now have to wire the pulled up end of the 100K resitor to the empty hole as shown in this picture for the HM TC to work, can you confirm what my new switch wiring would look like given I lost the trace on the hole next to the 100K resistor behind the TC on the HM:

https://drive.google.com/file/d/0BzSBmZGY0VqYTEhYM25taldBYWM/view

1) Normal Board - Wire pin 7 of the Cat5 jack to the top leg of the switch - should be no change on mine
2) Normal Board - Wire the middle leg of the switch to the resistor side of the 100K resistor behind the TC jack - Unsure on my current board??
3) Normal Board - Wire the bottom leg of the switch the wire side of the 100K resistor behind the TC jack - Unsure on my current board??

If it's not possible at this point, I'm ok with that.
 
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The switch wiring will not change from the original diagram, except that the wire that was coming out of the empty hole from the resistor (where you broke the trace) will now come from the hole for the standard probe jack (as you have wired). From there it is the same...

CAT5 pin 7 to one side of the switch
The wire mentioned above to the other side of the switch
The center lug of the switch to the top leg of the 100k resistor
 
RalphTrimble said:
The switch wiring will not change from the original diagram, except that the wire that was coming out of the empty hole from the resistor (where you broke the trace) will now come from the hole for the standard probe jack (as you have wired). From there it is the same...

CAT5 pin 7 to one side of the switch
The wire mentioned above to the other side of the switch
The center lug of the switch to the top leg of the 100k resistor
Click to expand...

Nailed it, thanks Ralph!
 
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