More ET-732 blues


 
I use both probes types. I find the ET732 much more finicky than the ET73. I always have to make sure that the ET-732 cables don't have any tight bends, and absolutely no kinks. I have issues where they enter the smoker and turn to quickly to get to the rack. I have no such issues with the ET-73 probes.

dave
 
I'm glad to hear that worked for you as well. I'm in the same boat about another day but I'd be happy to continue troubleshooting if anyone wants. Those are going back on the maverick Et 732 at this point which I also run as a failover alarm in case the pitdroid app or my phone chokes in the middle of the night.
 
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Dave, I think you said you had continuity between the braid and shield on the jack on your 732s in another thread didn't you?
 
I've been running ET-73 food probes without issue, just got myself an ET-732 pit probe and when I plugged it in it still said OFF. After messing around with all the software settings and moving the probes from port to port (each time the 73's worked and 732 said OFF on any port), I finally noticed if you pull the ET-732 probe jack out of the socket a little bit it comes to life. Next to the 73 plugs the 732 plug needs to stick out of the jack a bit further (not inserted all the way in). A quick visual inspection of the plugs and it is easy to see the 732 is a bit longer, don't know why, but that was causing my issue. Hope this info helps out someone else....

Just FYI, my ET-732 probe does NOT have continuity between the braid and the shield but does seem to be working properly (*when not plugged all the way in), the DC resistance measures 1.075Meg Ohms on my Fluke 76 True RMS meter. My ET-73 probes DO have continuity braid to shield, however.....

Edit:
Well, the new ET-732 functioned properly as a pit probe for about an hour, then suddenly it's showing OFF. Like others have posted, I sometimes see brief moments of readings from the probe. Since I noted previously that there is NOT continuity between the braid and the shield of the plug, it was easy enough to tap the braid to ground (LAN port housing) and bingo, I get a reading! Tap the braid to ground I get a reading, remove it no reading. Repeatable.

This finally kicks my brain in gear... The reason the 732 worked when it did is because the 732 braid (ungrounded) was touching the grounded braid from one of my 73 probes. If a 732 touches a 73 it gets the ground it needs, otherwise the 732 appears to be floating (no ground, don't know why)

So you need to tether the 732 and 73 cables together to ground out the 732 or figure out a way to get the braid permanently connected to the shield on your 732 probe (I am going to look into that in the morning). I'm interested to hear if this works for the rest of you that are having problems with the 732 probes, I think (hope) this may solve the issues....
 
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My 732 issues SOLVED.

You can read from my post above that I discovered the lack of connection between the braided wire and the shield of the probe plug seemed to be causing my problem with the 732 probe. So today I took a shot at an easy remedy which seems to have worked out great. I took a short piece of thin solid wire (like telephone wire or a wire out of a CAT5 cable) and made a couple loops around the plugs shield and a couple loops around the braid and very lightly and quickly soldered it in place on both ends. The probe now works fine (using the Maverick-732 preset), added bonus is the small amount of solder/wire on the plug now prevents it from being inserted too far...

IDK WHY this probe has a lack of gnd to the braid, or why the tip is longer than standard, but this mod seems to kill two birds with one stone...
(sorry for the poor pic, my "clever" phone doesn't have a flash so I had to hold a flashlight to get the shot)

732.jpg
 
So are the ET732 probes thermocouples or thermistors? I was thinking that around 300 F was the upper range for thermistors, and would thinking that a thermocouple would work better for BBQ temperatures; but it appears they are thermistors.

Also, I have a number of probes that don't work unless grounded. Is there anyway to fix this on the linkmeter board instead of having to run a jumper as Ralph has shown above?
 
They're thermistors as well. Some of the "high heat" probes from maverick are good up to 572F reading and can withstand up to 700F. I don't know why the ET-732s are so finicky, but I don't have any of them so I don't have any way of troubleshooting them. Nor do I want to :-D

I don't know why the braids would need to be grounded either. I mean if the two wires inside were completely isolated from the braid then the braid shouldn't have anything to do with anything. Taking apart an ET-732 device and reverse engineering how Maverick solves the problem might be useful in modifying the HeaterMeter design but that's well beyond my level of expertise.
 
I know, it's a bit of a stumper. I mean, if they are resistive probes you just need two wires to measure them. If the 732 works on the Maverick units apparently the two wires are connected to the plug, so why does the braid need to be grounded? You would think if they work on the Maverick unit they will work on the HM??? But yet the braid needs to be connected to the shield (or a ground) before they will work on the HM, strange.
For now my 732 is working fine with the above jumper wire in place, eventually I will get myself a new plug for this probe and will cut the OEM plug off and hopefully that will give me some insight into what is going on here. I will post back here if/when I figure this out furthur....
 
Bryan Mayland said:
They're thermistors as well. Some of the "high heat" probes from maverick are good up to 572F reading and can withstand up to 700F.
Click to expand...

Speaking of high heat probes....
I am thinking the next HM project I build may be a wood fired pizza oven. Temps get really high in a pizza oven, 500-700 degrees being the norm. I am wondering what probe that works with the HM has the HIGHEST temperature rating? Also, if you exceeded the range of a probe what happens? Does the reading get inaccurate or does the probe die?
 
Ralph, thanks very much for the info on how you fixed your ET732 probes (soldering a little wire from the braid to the shaft). I was having the exact same intermittent / dropping out issues as you describe. Would have been pulling my hair out big time trying to figure it out if it hadn't been for your post. Bryan, I'd really suggest this be put on the wiki somewhere as it'll save a lot of people the headaches.
 
It is in the wiki. Although the picture isn't there so I might add that.

Oddly enough, I bought one of the ET-732 smoker probes with my Amazon Millions for testing. Disappointingly enough, it works great and at least down to 76F.
 
RalphTrimble said:
Speaking of high heat probes....
I am thinking the next HM project I build may be a wood fired pizza oven. Temps get really high in a pizza oven, 500-700 degrees being the norm. I am wondering what probe that works with the HM has the HIGHEST temperature rating? Also, if you exceeded the range of a probe what happens? Does the reading get inaccurate or does the probe die?
Click to expand...

I had an ET-73 probe die when it got above 500 ºF. The display just read HHH and the probe never worked again.
 
Bryan Mayland said:
It is in the wiki. Although the picture isn't there so I might add that.

Oddly enough, I bought one of the ET-732 smoker probes with my Amazon Millions for testing. Disappointingly enough, it works great and at least down to 76F.
Click to expand...

My both ET-732 probes work without grounding the braid. Maybe they have changed something in the design. I obviously can't tell when my probles were made, but I bought my Maverick thermometer last year.
 
Bryan Mayland said:
It is in the wiki. Although the picture isn't there so I might add that.

Oddly enough, I bought one of the ET-732 smoker probes with my Amazon Millions for testing. Disappointingly enough, it works great and at least down to 76F.
Click to expand...

Bryan, are you sure the braided wire of the 732 wasn't touching ANY ground while you were testing? Another probes braid, anything metal on the rPi etc? Cause when I got my first 732 and plugged it in it worked like a champ and I thought "what is everyone talking about?", only later did I see the probe drop off. After fiddling with it is when I realized it only worked when the braid touched a ground, and if you have multiple probes plugged in it is pretty likely their braids are touching...

Did you test for continuity between the braid and the shield of the plug? (which is indeed lacking on both my 732 probes)
 
I'll have to check. I honestly haven't had a lot of HeaterMeter time between the 3D printer and family stuff. It very well might be touching the pit probe braid.

They definitely go in too far though. Even knowing it would I inserted it too far right on the first try.
 
LOL Me too! Since I got the 3D printer I've been pretty tied up with it, and learning the 3D apps and all. Last night I FINALLY used my HM in a case for the first time... Was really nice not having the bare boards stuck inside a tupperware container!

BTW, I am coming along nicely with the 3D printer, I am getting some pretty good prints and am finally starting to get a grip on 123D Beta to the point where I can create my own parts in a relative timely manner and print them out and get what I actually designed. I am working on some bushings for the linear bearings on the bed becuase clearance there is just too damn low. So far I have the top half done and printed, hope to complete the bottom half tonight and install them... If they work out I will give you the files in case you have the same problem with your printer ...
 
One of you 3d printer guys should print up some collars, in different colors, that we can slip on our ET-732 probes to keep them from inserting too far. A nice snug fit should do it.

Can you print something that small?

dave
 
I think it could be printed, but the wire I soldered on mine to connect the braid to the shield on the plug also prevents them from being inserted too far (and fixes the missing ground).
 
Hey,

I also use the ET-732 probes but with other probe connectors. Because order something from digikey in germany isn´t very easy I bought some other connectors.

I thought the are the same but it doesen´t look like it is because I can plug my probes all the way in without any problems. The probe connectors have a metal ring at the end where the plug are.

Maybe someone could find a similar part at mouser or digikey.

These are the connectors I have bought wich also fit at the current pcb design:

http://www.reichelt.de/index.html?;ACTION=7;LA=3;OPEN=0;INDEX=0;FILENAME=C160%2FDS_KLBR1.pdf

and here is a pictures how it looks with this probes(custom case)

At probe 2 there is the ET-732 and at Probe 4 there is a normal 2.5 mm jack wich I use for the ambient temperature.
 
The ET-732 probe I just received also had a plug that is too long meaning that they do not work when plugged in too far. Problem solved by cutting a 2mm length of silicon fuel hose and sliding this onto the plug to act as a stop. Good firm plug connection and no risk of it being pushed in too far and losing connectivity.
 
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