All TC probe HM?!?


 
I could make a rough board up over a weekend. A Din cable has 9 wires and a smaller jack then the rj45. So, Aux board would contain the 3.3v and all the TCs would share a GND, that would leave 4 wires for amp outputs. The best way and the cheapest way, would be to use k Jacks that mount to the smoker and not to the Aux board.
 
John, I am wondering what the need for the Din cable is? IF I read the scenario properly, he needs an Aux board that has only TC amps without connections for the fan and servo, as the fan and servo is the part that is far away from where the probes are located. So he would have a cable between the HM and the damper and another cable between the HM and the aux board, neither of those cables need more than 6 wires.
 
The Din cable would allow for just one cable, as two having two cables from the heatermeter. Then from the Aux board, you could run wire down to the blower and or servo.
 
Seems to me like you're sending the blower and servo wires to the aux board and back for no good reason, which bumps up the number of wires required, and increases the potential for noise on the probes (unnecessarily)....
but perhaps I misunderstand the scenario. I'm thinking the pit is large so the food probes are far from the fire box, and the HM would likely be near the firebox and damper but the probe leads wont reach there.
If I had to deal with this scenario I would make an AUX board with 4 TC amps and a CAT5 jack, using 6 wires for Probes 1-4 + gnd +3.3v. Then add a second CAT5 jack to the HM for the probes and run one CAT5 cable to the probes and another to the damper. This would give you a lot of freedom on where you place the HM and probes using standard cables. I figure if you add a CAT5 jack to your HM you'll know what to plug where, maybe install a blue cat5 jack for the probes, they seem to be on the shelf in most stores.
 
John did design the board for me.
Got all the parts never assembled it. I saved the drawings somewhere will check tomorrow when I'm home. Also think I got 4 of the boards made. Not sure we're it all is will look for it.
 
RalphTrimble said:
John, I am wondering what the need for the Din cable is? IF I read the scenario properly, he needs an Aux board that has only TC amps without connections for the fan and servo, as the fan and servo is the part that is far away from where the probes are located. So he would have a cable between the HM and the damper and another cable between the HM and the aux board, neither of those cables need more than 6 wires.
Click to expand...

Thanks guys for all the back and forth, great input. As Ralph has stated, this would be more to my ideal as I will have the HM located down by the damper/fan (where the firebox is at the bottom of the smoker) and the probes need to reach up a long distance, so an aux board located near the upper part of the smoker will work.
 
Dale Ward said:
John did design the board for me.
Got all the parts never assembled it. I saved the drawings somewhere will check tomorrow when I'm home. Also think I got 4 of the boards made. Not sure we're it all is will look for it.
Click to expand...


cool, please keep my posted on your search, I'd be interested to know more.
 
RalphTrimble said:
If I had to deal with this scenario I would make an AUX board with 4 TC amps and a CAT5 jack, using 6 wires for Probes 1-4 + gnd +3.3v. Then add a second CAT5 jack to the HM for the probes and run one CAT5 cable to the probes and another to the damper. This would give you a lot of freedom on where you place the HM and probes using standard cables. I figure if you add a CAT5 jack to your HM you'll know what to plug where, maybe install a blue cat5 jack for the probes, they seem to be on the shelf in most stores.
Click to expand...

yes please!
 
John Bostwick said:
I could make a rough board up over a weekend. A Din cable has 9 wires and a smaller jack then the rj45. So, Aux board would contain the 3.3v and all the TCs would share a GND, that would leave 4 wires for amp outputs. The best way and the cheapest way, would be to use k Jacks that mount to the smoker and not to the Aux board.
Click to expand...


keep me posted on what you come up with :)
 
I knew a couple people had worked on it. What you need is really simple, as long as you have EAGLE skills... just need to paste in 4 copies of a the TC circuit onto one board with a CAT5 jack, then add an extra CAT5 jack to your HM to connect to. I think John B could work that out for you pretty easily.
 
Thanks Ralph, yes it does seem simple, but unfortunately I am definitely not as knowledgable as you guys, which is why I reached out. So I truly appreciate all the feedback from everyone.
 
I haven't taken the time to figure out board layout in EAGLE, otherwise I would make up a board for you... That's why I collaborated with John B to make the RDTC Aux Thermocouple board. I had the background to layout the circuit and John had the experience to layout to board in EAGLE, so it worked out well working together (and John is an easy guy to work with, good people!). I think my vision of what you need makes sense to you and I, perhaps John B will be able to put together that board for you. Short of that, you could build up 4 individual AUX TC boards (the TC amp part only) and wire them together to get the job done.
 
All good stuff. It seems the more I dig into this, the more options there are. Don't spend too much time on this just yet, unless you really want to, until I figure out what direction I'm going, which at that time I'll likely reach out to you and JohnB for assistance.
 
I had 3 boards for it made at OSHPARK HeaterMeater AUX TC X3
https://oshpark.com/shared_projects/0BAQx2JO
Never did assemble them. John Bostwick designed the board.

Here is the parts list, it missing at least one or two parts that were added when John updated the board.

http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=367680ac63

I remember it was missing a part something to do with grounding

Here is message from John B back in December 28 2014

"The board has not been tested but it should work without issue as I just used the same Schematic as the Heatermeter. I will send you the files and a component placement chart to go with it.

Osh park cost $3.20 including shipping for 3 boards

John"
Click to expand...

Here is the original thread It talks about the missing parts.

https://tvwbb.com/showthread.php?56746-TC-AMP-board-for-3-probes
 
Last edited:
That thread was AWESOME! I surely need to improve my search skills, thanks Dale for posting it here. Very nice board designs from both JohnB and DanielK, and does get me closer to what I'm looking for.

Thought:
After reading the comments in that thread, here is a possible design direction for the HM5, make the probe connections an addon board that stacks onto the HM like what is being done with the display and RPi. I'm sure this will affect the case size/design but that can be worked out. Have different probe board configs that users could choose from; 4 TRs, 1TC 3TRs, (2 TCs 2TRs, 3 TCs 1 TR), 4 TCs. Doing so would allow the HM board to be simplified some more, and allow probe flexibility for the user, with the added benefit of allowing the user to change out probe boards as needs change without needing to build a whole new HM.
 
Last edited:
The beauty of the HM is that Bryan has made all of the code and files available for anyone to modify. This means you are free to come up with your own design and move forward with it. Hit up youtube and watch some PCB design videos and take a crack at modifying the PCB to fit your needs.
 
JohnW, TBHWY I think the request for an all TC HM is a rare one, and therefore it doesn't make much sense to re-design the board to add the option to use TC shields for each probe. As you can see now, there are a few avenues to pursue if an all TC HM is what you want, and making this mod is fairly straight forward once you decide on how you are going to build the TC amps.
There is no need to build a new HM to change probe configs, it's very simple to change between probe types, it just a matter of having a TC amp and switching in/out the pullup resistor for that probe. I worked out long ago a switch that can be added for the pit probe to switch between an external TC Pit Probe and an onboard standard pit probe, a simple double pole double throw switch can handle switching the probe inputs and switching the pullup resistor in/out at the same time.
As Steve said, the beauty of the HM is the open source nature, which gives you the freedom to make the HM the way YOU want it... in addition to that, the willingness of the HM community to help a brother out with a unique pursuit is also a plus. Personally I feel the all TC HM is and will remain a rare request, as the main reason for the TC pit probe in the first place was to make the pit probe capable of handling higher temperatures and a the harsh environment in the pit, food probes don't experience those sort of extremes as meat never really gets above 200F by much, so standard probes work just fine in the food probe role.
 
Last edited:
You must log in or register to reply here.

 

Back
Top