HeaterMeter Final Setup Question


 
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Pavlov_Jones

New member
Hi all!

Finally built my Heatermeter v 4.2.4 Thermocouple version, and the whole build went smoothly. I have mated it with a Raspberry Pi successfully. I have successfully set it up and accessed it via the network.

This looks to be a brilliant device so far.

I have read the setup information, but I cannot understand what is going on with the temperature and my only probe, the K-type connector Thermocouple.

Firstly, in configuration we have Probe 0, Probe 1, Probe 2, Probe 3 right?

I set Probe 0 to Internal with Vishay 10k, then Probe 1,2,3 to Thermocouple with mV/C 5.

On the home screen, Probe 0 reads 4.8°, and Probe 1,2,3, read as off.

I am confused because a) where is Probe 0 getting the temperature from?, and b) shouldn't probe 3 be the thermocouple? for which, it indicates off. What happened to the thermocouple reading? If I unplug it, it doesn't seem to make a difference.

When I set probe 0,1,2,3 all to Thermocouple with mV.C 5.

On the home screen, Probe 0 reads 482.2°, and again Probe 1,2,3 all read off. On the LCD, it reads - No Pit Probe -

Hmmm it's 1am, I'd better call it a night. Would be grateful if anyone can point me in the right direction. Does it have anything to do with removing the 10k resistor for the k-type connector because this was thermocouple? ....
 
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The first configuration you've set is backwards, Probe 0 is the control probe which is your Thermocouple 5 mv/C. The probes 1, 2, and 3 should be Internal (thermistor).

Looks like you got it right when you reversed the configuration, however I am not sure why it would say 482.2 on the Home screen and -No Pit- on the LCD, because they are the same information. No Pit means that there's no value being put out for the home page to display. Are you sure that you are seeing behavior? You might want to power cycle and check the homepage and configuration again.
 
Hi Bryan,

Ok. I have Set Probe 0 to Thermocouple, mVC 5, and Probe 1,2,3 to Internal (Thermistor) Vishay 10k.

Then I saved, and power cycled.

Upon reset the LCD no longer shows -No Pit Probe-, it displayed the ip address as normal, then shows Pit:43 Degrees. And it has been rising about 1 degree a second, it it now at 157.

EDIT: Probe 0 at home seems to be rising at 1 degree about every 1-2 seconds. It is now 269 degrees... It's just in a normal room here... no heat...

It seems to be better now but I'm still not sure what is going on. Thank you for responding so quickly, I really appreciate your advice!

Main thing is that the temperature is rising a degree very second starting at about 80 to now ... 170 ... I am sure this is a configuration I have messed up somewhere...
 
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I reset to:
Probe: 0 = Thermocouple 5mvc
Probe: 1,2,3 = Internal, Vishay 10k

Then turned off. Washed it in isopropyl alcohol, then turned it on again.

The temperature is now reporting a much more sensible, and much more realistic 67 degrees F ... slightly falling, rising, falling ... but very sensible... nothing as dramatic as before where it was reporting in the hundreds of degrees and rising.

I think I can get this working...

UPDATE: MISSION CONTROL, SYSTEMS ARE A GO!

I cupped my hand over my thermocouple, and the graph reflected an upwards curve until I took my warm hand away. IT WORKS!

Now to go and get the blower working and clean the bbq.

SO EXCITED NOW! Must either have been the setting, or the isopropyl clean! Thanks for the initial guidance Bryan!
 
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Ok. I tried a different K type Thermocouple from Auberin. It reads around 40 degrees celsius when it is 20 degrees celsius actual... I'll update when I know more.

I did the hot hand on thermocouple test, and it adjusted for that, so it works, but the probe is double the real temp... hmmm

Essentially, my problem is that the thermocouple reported temperature is approximately double the actual room temperature. Would appreciate any suggestions for possible avenues of exploration to solve this...
 
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It almost seems like it is just floating and that maybe the temperature being right sometimes is just coincidental? Just to be sure, you don't have the 10k resistor installed by the thermocouple but do have the 100k resistor installed in the 100k spot? Maybe you could post a close up picture of the thermocouple area (both sides of the board).

You can also do a test without a thermocouple at all to take that out of the equation. Just insert a bit of wire into both + and - jacks of the thermocouple connector (I usually use a cut off bit of component lead). When shorted like this, the amplifier will tell you what its temperature is so that should stay relatively stable for testing.

It's not important right now, but the other 3 probes aren't Vishay 10k. The 10k resistance you're thinking of is what is in the "Resist" box. The drop down indicates the model of probe you have plugged in, which will be probably Maverick or Thermoworks whenever you add food probes.
 
I ran into TC probs on one board and it drove me nuts. I basically ended up scrubbing the TC components about 5 or 6 rounds with 99% isopropyl alcohol and it finally started acting normal.
 
I agree with Bryan, it sounds like the TC is floating.... Meaning, the TC amp is not connected to the ATMega (or the TC amp is not functioning). If there is no working TC amp connected to the ATMega the HM usually will not report "NO PIT PROBE" when there is no TC plugged in, instead the Pit probe will show a temp that starts low and keeps rising upward with no correlation to the actual temperature.

Did you do the SMD soldering work yourself? If so, inspect the connections with a magnifying glass, and Steve_M gave you good advice, clean the board with isopropyl alcohol and a soft bristle brush. LET THE BOARD DRY COMPLETELY before you power it up, often times this will fix probe issues...

Also, behind the TC probe jack there are the three components, a .1uf cap, 100K resistor and 10K resistor... The 10K resistor should NOT be installed, it is the one that is turned a different direction than the rest of the resistors that stand up in that area. The 100K resistor and .1uf cap are the RC filter, these are the components that the TC amp output goes through right before it connects to the ATMEGA. The TC should connect to the ATMEga through the bottom corner pin that is behind the TC jack...

If you did the TC solder work yourself perhaps shoot a close up pic of that part of the board and post it here, maybe somebody can spot your problem for you...

Also, in a case like this it is a good idea to open up the yellow connector on the end of your TC and take a look at what is going on in there. Sometimes those wires can be loose or there can be wire with the insulation removed long enough to short out if you twist the TC cable around. So make sure the TC itself is in good working order....
 
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