I see that you do have it listed in the parts list wiki & I thought I remembered having seen it there as well previously but prior to posting when I looked I didn't see that link any longer - I'm guessing I had an old version of the page cached on the laptop I was using at the time. Thanks, I'll go ahead & pull the trigger for the mouser order w/ the non-P parts.
HeaterMeter v4.1 PCB now available
- Thread starter Bryan Mayland
- Start date
Neil Mager
TVWBB Member
I'm about to upgrade from my linkmeter, (took a break while building a 3d printer). Now the printer is running, back to a new HeaterMeter. 2 questions: First is timing, are the 4.1 boards good to go
or should I wait? Second is Assuming 4.1, Anybody have an extra, otherwise I'll get the 3 boards.
Thanks,
Neil
or should I wait? Second is Assuming 4.1, Anybody have an extra, otherwise I'll get the 3 boards.
Thanks,
Neil
Gary Graham
TVWBB Fan
Hi,
I am building a v4.1 heatermeter and have a question about the Thermocouple amp and other parts needed for the tiny thermocouple board.
I ordered the v4.1 parts list form Mouser and just noticed there is no thermocouple amplifier in the list. Does anyone have a shopping list for the thermocouple parts I need ? I saw a link for the panel mount or PCB mount thermocouple connectors... will a PCB mount connector work with the tiny PCB with respect to being close to the edge of the Pi or HM board where it would be natural to have a connector ?
<edit> I did some more reading and found another thread with the answers...
http://tvwbb.com/showthread.php?47505-Thermocouple-Board-Success-(sort-of)&p=570458&viewfull=1#post570458
The thread says the details are in the schematic, and a panel mount connector is used.
I am building a v4.1 heatermeter and have a question about the Thermocouple amp and other parts needed for the tiny thermocouple board.
I ordered the v4.1 parts list form Mouser and just noticed there is no thermocouple amplifier in the list. Does anyone have a shopping list for the thermocouple parts I need ? I saw a link for the panel mount or PCB mount thermocouple connectors... will a PCB mount connector work with the tiny PCB with respect to being close to the edge of the Pi or HM board where it would be natural to have a connector ?
<edit> I did some more reading and found another thread with the answers...
http://tvwbb.com/showthread.php?47505-Thermocouple-Board-Success-(sort-of)&p=570458&viewfull=1#post570458
The thread says the details are in the schematic, and a panel mount connector is used.
Last edited:
Gary Graham
TVWBB Fan
I am building my HM v4.1.4 tonight, and I am back again with thermocouple questions.
I read all 10 pages of the Thermocouple board success thread and did not see a picture of a v4.1.4 board with its thermocouple board and connections.
Does anyone have a picture of one of these thermocouple boards connected to the HM showing the layout for the panel connector for the TC to share ?
So I understand the thermocouple board connections go in place of one of the probe jacks, but I am asking to be sure before soldering any of my probe jacks on.
For my application, I want to have the pit probe for PID control, a fire probe (the thermocouple) and a couple of meat probes.
Should I keep the pit as probe0 (for control) and think about using one of the other probes for the thermocouple ?
I think I saw in the code for the config screen where any probe can be designated as the control probe and you can rename a meat probe to something like "fire" ...is that correct ?
Does anyone use the J2 connector pins for thermocouple connections? (would be only 2 of the wires needed though).
I read you need to lift one of the 10k pullup resistors to properly connect the thermocouple board, and since I already soldered the resistors in, I cannot tell which one is R18, etc... Could use a pointer to a picture of the v4.1 PCB without resistors in place.
Also, will Q3 (the fan driver MOSFET) drive a bigger load, like a couple of 2" muffin fans or should I try it and see if it heats up, or just upgrade that part ?
Thanks....
I read all 10 pages of the Thermocouple board success thread and did not see a picture of a v4.1.4 board with its thermocouple board and connections.
Does anyone have a picture of one of these thermocouple boards connected to the HM showing the layout for the panel connector for the TC to share ?
So I understand the thermocouple board connections go in place of one of the probe jacks, but I am asking to be sure before soldering any of my probe jacks on.
For my application, I want to have the pit probe for PID control, a fire probe (the thermocouple) and a couple of meat probes.
Should I keep the pit as probe0 (for control) and think about using one of the other probes for the thermocouple ?
I think I saw in the code for the config screen where any probe can be designated as the control probe and you can rename a meat probe to something like "fire" ...is that correct ?
Does anyone use the J2 connector pins for thermocouple connections? (would be only 2 of the wires needed though).
I read you need to lift one of the 10k pullup resistors to properly connect the thermocouple board, and since I already soldered the resistors in, I cannot tell which one is R18, etc... Could use a pointer to a picture of the v4.1 PCB without resistors in place.
Also, will Q3 (the fan driver MOSFET) drive a bigger load, like a couple of 2" muffin fans or should I try it and see if it heats up, or just upgrade that part ?
Thanks....
Bryan Mayland
TVWBB Hall of Fame
I think I'm the only one that's ever built one and was so disappointed with the performance I removed the board from my HeaterMeter. That's why there's no pictures of them anywhere.
The idea is that it just fits over the probe jack holes (the probe jack must be removed). It can go on any probe position but you need to cut the traces leading to the two circles on the main PCB for the probe you want to replace. The PIT is the only one that has the cutable solder trace area, but the others are just as easily cut. You can also use J2 instead on the output of the thermocouple board and just feed it into the HeaterMeter.
The two circles on the TC board are TC+ (bigger hole) TC- (smaller hole) and the pins across the top are 3V3, Output, Gnd.
The code to change which probe is the control probe is in HeaterMeter but it is compiled in so you can't change it at run time.
Q3 will drive a pretty big load, tested at at least an amp continuous duty.
John Bostwick
TVWBB Wizard
I was collecting those little boards for something as of yet unknown, lol.
RalphTrimble
TVWBB Diamond Member
I think you got your answers from Bryan above, but for what it's worth, I built a stand alone thermocouple amp circuit (from the 4.2.3 beta circuit diagram) and have been using it outside of my HMv4.2.3 through the CAT5 cable, I see no reason you wouldn't be able to do this on your HMv4.1. That said, you would want to follow the circuit diagram for the thermocouple amp from the upcoming HMv4.2.4 release, not the diagram from the HMv4.1. They are very similar but not exactly the same, I am not completely sure what changes/additions you may have to make to your circuit match the working version we are all using now, but I think you should be able to build to from your little HMv4.1 thermocouple board if you compare the new circuit diagram (when released) to what you have there.
As for connecting it to your HM (through the CAT5 jack), I jumpered over 3.3V and gnd to spare pins inside the HM to the CAT5 jack to power the thermocouple amp, you connect the thermocouple to the external amp with proper (inline) type K thermocouple connectors, and run the output of the thermocouple amp back to the HM through another spare wire in the CAT5 cable. Inside the HM you would jumper over that wire from the CAT5 jack to the input you want to use for the thermocouple. I haven't examined the HMv4.1 circuit to figure out exactly where/how to connect that wire, but I think you should be able to connect it in a similar manner as the (optional) ambient temp thermistor. You will have to remove the pullup resistor for whatever probe you decide to connect the thermocouple to. I would also recommend that you add the RC filter inline with the jumper you install inside the HM for the thermocouple lead, which is very easy, just a resistor in series and a cap to ground. (again, reference the HMv4.2.4 schematic when released). In the HM config select Thermocouple as the probe type for that probe, and set the gain at 5 mV/C. As Bryan noted, there is not a provision to select which probe is the pit probe in the software, so keep that in mind when you select which probe to use. If you want the thermocouple to control the pit use Probe0, if you want it to monitor the fire but not control the pit then select another probe. There is a more detailed description of my external thermocouple amp in my thread titled HMv4.2.3 build questions.... Hope this info was helpful.
As for connecting it to your HM (through the CAT5 jack), I jumpered over 3.3V and gnd to spare pins inside the HM to the CAT5 jack to power the thermocouple amp, you connect the thermocouple to the external amp with proper (inline) type K thermocouple connectors, and run the output of the thermocouple amp back to the HM through another spare wire in the CAT5 cable. Inside the HM you would jumper over that wire from the CAT5 jack to the input you want to use for the thermocouple. I haven't examined the HMv4.1 circuit to figure out exactly where/how to connect that wire, but I think you should be able to connect it in a similar manner as the (optional) ambient temp thermistor. You will have to remove the pullup resistor for whatever probe you decide to connect the thermocouple to. I would also recommend that you add the RC filter inline with the jumper you install inside the HM for the thermocouple lead, which is very easy, just a resistor in series and a cap to ground. (again, reference the HMv4.2.4 schematic when released). In the HM config select Thermocouple as the probe type for that probe, and set the gain at 5 mV/C. As Bryan noted, there is not a provision to select which probe is the pit probe in the software, so keep that in mind when you select which probe to use. If you want the thermocouple to control the pit use Probe0, if you want it to monitor the fire but not control the pit then select another probe. There is a more detailed description of my external thermocouple amp in my thread titled HMv4.2.3 build questions.... Hope this info was helpful.
Gary Graham
TVWBB Fan
Thanks for all the replies.... so is everyone saying not to bother using the v4.1.4 thermocouple board and that v4.1 reference schematic after all ?
Rather, just wait and use the v4.2.3 schematic (when released) on the v4.1.4 board (?)
To connect the tiny thermocouple board, pull out the appropriate 10K resistor from the HM board and run two jumper wires where the 10k resistor was and connect to the tiny board for the 3.3v and amp out connection. Connect ground to some ground on the HM board like the common pin on the J2 connector, and hook the thermocouple to the +- big holes or suitable connector. (I used a RS speaker terminal block on my other project). cheep.
Rather, just wait and use the v4.2.3 schematic (when released) on the v4.1.4 board (?)
To connect the tiny thermocouple board, pull out the appropriate 10K resistor from the HM board and run two jumper wires where the 10k resistor was and connect to the tiny board for the 3.3v and amp out connection. Connect ground to some ground on the HM board like the common pin on the J2 connector, and hook the thermocouple to the +- big holes or suitable connector. (I used a RS speaker terminal block on my other project). cheep.
RalphTrimble
TVWBB Diamond Member
Well, as Bryan (the developer) said, he built that (first) thermocouple board up and didn't have good luck with it, so he abandoned that design and moved on to the circuit is found on the 4.2.X boards. I don't know of anyone else that has used that little board you have there....
I have built the new v4.2 circuit and it works great for me and I haven't heard of it not working for any of the v4.2 beta testers, so I think this is a good circuit and I would recommend that you work with that design. I think the circuit design is fairly similar to what you have there, but some of the component values are changed, and there are a few resistors added at the thermocouple connection, so I think you COULD use that little board as a base to build the new circuit onto if you note the changes and add the missing components. I would abandon the idea of piggy back soldering the board to your main HM board, that is a dead concept, I would wire it in manually. I would also caution you about your terminal block connection because a thermocouple connection is actually quite specialized, the terminals need to be made of certain metals to match you thermocouple type otherwise it will influence the temperature readings. So, you need to use a real thermocouple connector to make that connection. You can get inline thermocouple connectors, and panel mount connectors as well, I would suggest you look into one of those options.
I have done quite a bit of experimentation with the thermocouple at this point. I have used the thermocouple through a long CAT5 cable, wiring a thermocouple connector to the copper wire and running the raw thermocouple output down the CAT5 cable. This "worked" but required quite a bit of offset to read the proper temperature, and the required offset would change as the temperature differential between the thermocouple junction and the thermocouple amp (inside the heater meter) changed, so that's a bad idea. I have also experimented with running an external thermocouple amp out at the grill, with the thermocouple plugged into a proper inline thermocouple connector with a very short bit of copper wire running from that to the (external) amp, then running the output of this amp down the same long CAT5 cable. This works great, requires no offset at normal ambient temps, however I have only been able to test it in ambient temperatures from around 55F to 90F, it did work reliably in that temperature range....
SO.... I would tell you to first get ahold of the new thermocouple amp circuit and mod your board to match that design (I built my external amp on an IC socket using "flying leads" on all of the components, so it can be done and is not THAT picky of a circuit). Then I would tell you to either get a real thermocouple connector and connect it to your amp. You could build the amp into the HM and use a panel mount connector mounted in your HM case (so the amp and connector are held at the same temperature) or you could use the amp outside of the HM using an inline thermocouple connector (the critical thing here is the amp and the thermocouple connector/junction must be held at the same temp). You can connect the thermocouple through the CAT5 cable by running 3.3v and ground out of the HM on two spare CAT5 wires, then running the output of the amp back down a third spare wire, which you would then jumper over to one of your probe leads inside the HM. You must remove the pullup resistor for this probe, and I would recommend that you install the RC filter (resistor and capacitor) inline with the thermocouple to remove noise from the signal. I think I said all this before, but you seem to still have questions so I am trying to help you out here...
I have built the new v4.2 circuit and it works great for me and I haven't heard of it not working for any of the v4.2 beta testers, so I think this is a good circuit and I would recommend that you work with that design. I think the circuit design is fairly similar to what you have there, but some of the component values are changed, and there are a few resistors added at the thermocouple connection, so I think you COULD use that little board as a base to build the new circuit onto if you note the changes and add the missing components. I would abandon the idea of piggy back soldering the board to your main HM board, that is a dead concept, I would wire it in manually. I would also caution you about your terminal block connection because a thermocouple connection is actually quite specialized, the terminals need to be made of certain metals to match you thermocouple type otherwise it will influence the temperature readings. So, you need to use a real thermocouple connector to make that connection. You can get inline thermocouple connectors, and panel mount connectors as well, I would suggest you look into one of those options.
I have done quite a bit of experimentation with the thermocouple at this point. I have used the thermocouple through a long CAT5 cable, wiring a thermocouple connector to the copper wire and running the raw thermocouple output down the CAT5 cable. This "worked" but required quite a bit of offset to read the proper temperature, and the required offset would change as the temperature differential between the thermocouple junction and the thermocouple amp (inside the heater meter) changed, so that's a bad idea. I have also experimented with running an external thermocouple amp out at the grill, with the thermocouple plugged into a proper inline thermocouple connector with a very short bit of copper wire running from that to the (external) amp, then running the output of this amp down the same long CAT5 cable. This works great, requires no offset at normal ambient temps, however I have only been able to test it in ambient temperatures from around 55F to 90F, it did work reliably in that temperature range....
SO.... I would tell you to first get ahold of the new thermocouple amp circuit and mod your board to match that design (I built my external amp on an IC socket using "flying leads" on all of the components, so it can be done and is not THAT picky of a circuit). Then I would tell you to either get a real thermocouple connector and connect it to your amp. You could build the amp into the HM and use a panel mount connector mounted in your HM case (so the amp and connector are held at the same temperature) or you could use the amp outside of the HM using an inline thermocouple connector (the critical thing here is the amp and the thermocouple connector/junction must be held at the same temp). You can connect the thermocouple through the CAT5 cable by running 3.3v and ground out of the HM on two spare CAT5 wires, then running the output of the amp back down a third spare wire, which you would then jumper over to one of your probe leads inside the HM. You must remove the pullup resistor for this probe, and I would recommend that you install the RC filter (resistor and capacitor) inline with the thermocouple to remove noise from the signal. I think I said all this before, but you seem to still have questions so I am trying to help you out here...
Gary Graham
TVWBB Fan
Thanks for the extra detail Ralph. Sounds like your cat5 work is doing well. I also like your approach to the thermo breakout board... does that allow you to use "normal size" components ?
Let me know when the v4.2 schematics are released so I can resume or re-build my TC board. I assume that RC filter will be in the new schematic as well (?)
Let me know when the v4.2 schematics are released so I can resume or re-build my TC board. I assume that RC filter will be in the new schematic as well (?)
RalphTrimble
TVWBB Diamond Member
The thermocouple amp is only available in SMD as far as I could find, so you have to deal with that no matter what. Check you PM inbox here at TVWBB...
Gary Graham
TVWBB Fan
Another question on my v4.1.4 build. I want to use the i2c to connect to other devices. Is there a good place to pick up the connections ?
I see the labels on the GPIO header, but cannot tell if these pins go to decent sized soldering pads somewhere on the HM board.
I see the labels on the GPIO header, but cannot tell if these pins go to decent sized soldering pads somewhere on the HM board.
Bryan Mayland
TVWBB Hall of Fame
The I2C pins aren't connected to anything on the HeaterMeter board, so the only place they would be accessible are right on the header.