HeaterMeter Hardware v4.2.4


 
Read the datasheets precise information, but it is 3C initial accuracy, 0.3% gain error. That means the that at 100C it might read 103C, but at 1000C it will read 1003C +/- 0.15%. The "initial accuracy" is constant across the range. The decimal values are significant but are relative to the initial accuracy. If readings varied by 3C HeaterMeter couldn't control the BBQ, but they don't they vary with temperature but offset by the initial accuracy plus the gain error and ambient temperature rejection.

I don't think 3C makes a big difference in BBQ and if anyone thinks they can control the temperature in a charcoal BBQ to less than 3C tolerance they're completely wrong about their ability. You can calibrate out the 3C error at your target temperature but I guarantee you that the temperature hitting two parts of the same pork butt varies by 3C at least.
 
Exactly what i wanted to hear ;)
And I forgot that the thermocouple is for PIT temperature only. What i really care about is meat temperature. My mistake.
 
Oh yeah I totally agree with you there. A 3C difference in the final cooking temperature can definitely be the difference between "tough" and "pullable".
 
Hi,

I have a HM 4.2.4 and ordered all parts for it, including the optional parts.

There is no description or any pictures where to solder the optional 10k ambient NTC. ("Only if you want an onboard 'ambient' temperature sensor")

I read about soldering it internal on a 2,5mm jack on an HM4.1, but I've seen nothing about it for HM4.2.

Is it for external use in one of the 2,5mm jacks?
 
The optional ambient temp sensor is wired exactly the same on every version of the HM to date if you want to have it mounted to the HM board. If you prefer to have the ambient temp sensor outside of the HM (so it reads a more accurate ambient temp uneffected by the heat inside the HM case) you just need to get a mono 2.5mm phone jack and wire the sensor across the tip and sleeve terminals then plug it into your HM probe jack.
 
I am pleased to report that due to the volume of sales I am able to buy from suppliers in larger quantity and am continuing to lower the price on the HeaterMeter kits. I've cut the price another 4% and I think we've reached the point that it's now cheaper to get a kit than it is to buy from the individual suppliers. Thank you to the 352 folks who have ordered kits since the store opened at the beginning of the year! (New prices effective Wednesday)

I'm down to under 20 Raspberry Pi model Bs, but with many thanks to the help of Kevin Akers in redesigning the HeaterMeter Pi PCB hopefully the test boards I have coming in this weekend will prove to be as sound as the 4.2.3 board and we can have a solution for the more readily available Raspberry Pi 2.
 
Bryan Mayland said:
I am pleased to report that due to the volume of sales I am able to buy from suppliers in larger quantity and am continuing to lower the price on the HeaterMeter kits. I've cut the price another 4% and I think we've reached the point that it's now cheaper to get a kit than it is to buy from the individual suppliers. Thank you to the 352 folks who have ordered kits since the store opened at the beginning of the year! (New prices effective Wednesday)

I'm down to under 20 Raspberry Pi model Bs, but with many thanks to the help of Kevin Akers in redesigning the HeaterMeter Pi PCB hopefully the test boards I have coming in this weekend will prove to be as sound as the 4.2.3 board and we can have a solution for the more readily available Raspberry Pi 2.
Click to expand...

This is great news! Looking forward to hearing more about the Raspberry Pi 2 solution. Will you have to migrate off of OpenWRT Attitude Adjustment to a different OpenWRT distribution?
 
Nope it is all the same software, just a new form factor which is a 3.7"x3.7" cube and somewhere in the neighborhood of twice as thick. It should fit the old Pis and the new Pis I believe, but cost a few dollars more. There are no new hardware features apart from fitting with a Pi 2 and B+.
 
Button solution! 4x 12mm tactile buttons on a second PCB. The HeaterMeter board can be built without the LCD and buttons to save on the cost (cuts the price of a kit almost in half).
VAE31C0.png
 
So how does this board attach to the main HM board? I assume through the headers there... but will there be sockets on the HM board, like a shield, or will this be another piggyback soldered situation like the LCD on the HMv4.2.4? I assume this board has to sit above the main HM board a bit and that is the reason why this HM will be thicker than previous versions?
How about some mounting holes for this daughter board in case you want to run it away from the main board?
 
I see a flood of "my (uo|down|left|right) button is stuck" posts waiting to happen, since you have to correctly orient each button for the N/O connection to be on the proper side.
 
There are pin headers on the main board and sockets on this board (or vice versa) and the connect like an Arduino does with a shield. All of the soldering is normal-style now, although I can't remember if the lcd goes on the back or the front. And yeah with all the space taken up by the buttons and LCD module, it was impractical to try to keep it all on one layer, so I went up. It is considerably thicker than the current HeaterMeter but a lot less wide (the output jacks start right at the edge of the pi). The 3.7" size also makes it so you can build a HeaterMeter bard with 4x thermocouples (using the same LCD backpack).
 
Steve_M said:
I see a flood of "my (uo|down|left|right) button is stuck" posts waiting to happen, since you have to correctly orient each button for the N/O connection to be on the proper side.
Click to expand...
Actually both sides are N/O, the schematic part only has the indicator on one side to remind the PCB layout guy which 2 pins are connected and which are switched. The buttons also truly only go in one way or rotated 180 degrees and work both ways, unlike the current directional control which only gently protests if you try to put it in the wrong way.
 
RalphTrimble said:
The optional ambient temp sensor is wired exactly the same on every version of the HM to date if you want to have it mounted to the HM board. If you prefer to have the ambient temp sensor outside of the HM (so it reads a more accurate ambient temp uneffected by the heat inside the HM case) you just need to get a mono 2.5mm phone jack and wire the sensor across the tip and sleeve terminals then plug it into your HM probe jack.
Click to expand...

So, as far as utilizing probe ports, this would be interchangeable with a food probe, right? I am not there yet in my build, but I will be putting together a RDTC that would run into my house via ethernet to connect to my HM. On the RDTC, I was planning to sacrifice the ambient temp sensor in favor of the TC pit probe and 2 standard probes, but it sounds like I could have the TC probe, 1 food probe, and the ambient probe, OR the TC probe and 2 food probes. Is that correct?
 
If you leave a food probe out in the air you have.... an ambient temp probe.... No matter how you use them the RDTC board will allow you to connect a TC Pit Probe and two standard probes. The HM will still have one last probe available (food probe 3) which is not able to plug into the RDTC due to the limit of 8 wires in the CAT5 cable, so that last probe has to plug directly into the HM or be an ambient temp thermistor like the Vishsay soldered to the probe jack on the HM board.
 
RalphTrimble said:
If you leave a food probe out in the air you have.... an ambient temp probe.... No matter how you use them the RDTC board will allow you to connect a TC Pit Probe and two standard probes. The HM will still have one last probe available (food probe 3) which is not able to plug into the RDTC due to the limit of 8 wires in the CAT5 cable, so that last probe has to plug directly into the HM or be an ambient temp thermistor like the Vishsay soldered to the probe jack on the HM board.
Click to expand...

Ralph - Thanks for making that light bulb go off above my head. I have plenty of maverick probes to accomplish what I want. I often find myself digging much deeper than necessary :)

If I move and wanted to wire my new house up to have my HM inside, I would probably give this a shot. http://www.l-com.com/d-sub-5-pair-26-awg-bulk-cable-100ft-spool

- - - Updated - - -

Of course that would require an update to the RDTC :)
 
The CAT5 jack on BOTH the Heater Meter and the RDTC board have only 4-pairs (8 wires total), so you are not going be able to use the 5th pair of wires in that cable unless you break those last two wires out of the cable on both ends. Not worth the trouble if you ask me, but to each his own.

FYI, if you get a mono 2.5mm plug you can solder the vishay thermistor (used for ambient temp) across the two terminals and then plug the ambient temp thermistor in on the outside of the HM case (where the reading more accurately reflects the ambient temp) or into one of the standard probe jacks on the RDTC if you like. If you did go with the 5-pair wire you could do the same, wire the vishay to the 5th pair on the grill end and put a 2.5mm phone plug on the Heater Meter end and plug it into Food Probe 3.
 
Last edited:
You must log in or register to reply here.

 

Back
Top