Heater Meter V4.2.3 build questions


 
Oh I guess you don't have to force it, as I just did it and it worked. Just go to System -> Software and paste the URL in the "Download and install package" box.
 
OK, cool, just did that and now I see the option to run the fan output by Pulse or Voltage....

There were two lines that came up in red after I installed that package though, not sure if that indicates a problem...

Here is what it reported afterward:

Downloading http://home.capnbry.net:22674/rpi/packages/linkmeter_10_brcm2708.ipk.
Installing linkmeter (10) to root...
Stopping LuCId superserver: lucid.
Starting LuCId superserver: lucid.
Configuring linkmeter.
lucid[886]: Unable to load certificate: /etc/nixio/cert_main.der
lucid[886]: Unable to load private key: /etc/nixio/rsa_main.der
 
That should be OK, it is just telling you that there is no certificate for HTTPS. I can't remember if it creates one automatically after the first try or not, but it shouldn't affect HTTP.
 
RalphTrimble said:
Well, I was thinking the isolated DC-DC 5V regulator would isolate the electronics from real ground (that you touch with your feet etc), but leave the 3.3V and 5v on the same "lifted" ground, since the 3.3v is regulated from the 5v. I would guess the reason for the larger size of the isolated unit is some sort of transformer, no matter how you slice it a transformer is gonna be a large-ish item compared to most of the parts in the HM....
Just thought I would throw that idea out there after I noticed the DC-DC we are using is non-isolated, which made me realize there must be other versions that are isolated... How much current on the 5v line do we need to run the HM?
Click to expand...
Yeah isolation means you'll need a transformer, and HeaterMeter itself needs about 25-50mA but it has to power the Pi too which means like an amp on the 5V side. The size of that transformer makes it impractical unless one was going to build the 12V power supply into the HeaterMeter case. You'd need something like this 5V supply except in 12V form. EDIT: 12V form.
 
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I sourced the caps and resistors I was missing today and got the HM4.2.3 board finished, powered up first time around without issue...
I had left that SMD resistor that sets the thermocouple impedance off as you advised I do, when I first powered up without that resistor is was showing the pit probe at about 430 something degrees without a probe connected. Right away I realized I forgot to tap in that resistor in so I put a 10K (1/4W) resistor in that spot. Now I get "No Pit Probe" when the thermocouple isnt plugged in, good deal I'm thinking. Then I plug in the Thermoworks thermocouple and it's reading about 700 degrees or so.... it's a bit off there! (by about a factor of 10!). I assume I need to adjust the mV/C setting for the thermocouple, so I dropped a "0" and went from 10,000 to 1,000, now I am reading about 95 degrees in a 78 degree room.... Any hints on how to get the right setting for the thermocouple would be appreciated....
One other thing, when the HM home page loads the Probe Names, temps and setpoints are all blank for a few seconds then they all appear, kinda lagging each time I come in/out of config or load the home page. Not sure what that issue may be? Once upon a time I had a HMv4.1.1 that had kinda similar lagging issues, turned out the ATMega chip came unseated a bit when I dropped the thing, or I should say, once I removed and reseated the ATMega the problems went away but I can't be SURE the drop was the cause.... At any rate, wondering if perhaps I have a poor connection somewhere or something else going on? What do you think?

EDIT: I tried to install the latest AVR firmware but it failed to download (noticed the release version is showing newer than the latest snapshot today?) At any rate, that led me to discover it looks like I had a typo in the DNS server, so I corrected that and now the lag is gone.... I really didn't think a bad DNS number would cause that, but...? Glad the lag is gone, running the latest firmware, hope to test this baby out soon, but I'm not used to running the HM boards without a case, back to the tupperware for now I guess....
 
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Here are some pics in case anyone is interested....
HM4.2.3TOP.jpg

HM4.2.3Bottom.jpg

HM4.2.3DVI.jpg

HM4.2.3Side.jpg


It's a real nice tight and compact unit!

Just noticed that there is no backlight on the display though, I guess I'll have to look into that...

The thermocouple reacts crazy fast, the temp graph shoots up like a rocket from the heat of my hand as soon as I grab it... I had backed down the thermocouple mV/C setting to 750 and it is hitting accurate room temp, but put the thermocouple under my tongue and got 103, so either I'm sick or something is still outta wack... wow, this thing reacts fast to temp changes though, almost instantaneously....
 
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RalphTrimble said:
I assume I need to adjust the mV/C setting for the thermocouple, so I dropped a "0" and went from 10,000 to 1,000, now I am reading about 95 degrees in a 78 degree room.... Any hints on how to get the right setting for the thermocouple would be appreciated....
Click to expand...
haha oh I forgot to tell you about this. Because the coefficient shares the same "slot" as a steinhart coefficient, that number isn't right at all when you change probe types. The AD8495 is a 5mv/C amplifier so the number should be 5.
One other thing, when the HM home page loads the Probe Names, temps and setpoints are all blank for a few seconds then they all appear, kinda lagging each time I come in/out of config or load the home page. Not sure what that issue may be?
Click to expand...
This is related to any time difference between the HM and your machine, as well as the whims of the browser cache. When the page loads it contains the latest HeaterMeter data along with the timestamp of the data. If there is a difference in time, the code queries for new data and has to wait for it to arrive which is that lag you see. If the browser displays the page from cache, the data will be old as well so it has to query it too. If everything is perfect it looks seamless but if anything goes wrong along the way you get that 1-5 second lag. I think in your case the DNS was preventing the time from syncing so your browser kept refreshing the data.

The avr firmware v10 image is still the one from March, but I moved it to the folder and now it has the wrong timestamp on it. The snapshot is still the most recent build.

Your backlight isn't lit because you didn't fill in the "0" ohm resistor I think. The silkscreen for it is on the wrong side so it isn't obvious.
 
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Thanks for the info, I will correct the thermocouple setting and install the jumper for the backlight, cause you are correct, I didn't put a jumper anywhere...
I must say, all your hard work trying to eliminate noise on the probe lines has paid off big time, I have never seen my temp graph so flat and stable on any of my other Heater Meters... They've always been plenty good to cook with, but this unit is showing me flat lines without deviation, hardly a ripple anywhere... awesome!
 
Tom Kole said:
You should have a design to test by the end of the weekend.
Click to expand...

Tom, you beat me to the punch, I was just about to post asking if you guys were working on a case.....
I assume you are gonna make a thermocouple version and a standard non-thermocouple version? Or are you gonna make the standard version have some sort of cutaway you can pop out to accommodate the thermocouple?
At any rate, I will be eager to print it up and test it out....
 
Bryan, I have bumped up against a bit of a dilemma here...
I want to test this baby out over my CAT5 cable, see how the MOSFET booster is working etc, but I can't because of the thermocouple pit probe.... Any chance of a software solution to this dilemma?
 
Bryan Mayland said:
I just emailed you a hex file with the FOOD1 probe controlling the PID.
Click to expand...

I just loaded the firmware you sent me, the HM LCD is now showing the Pit and Probe1 at the same temp (with only Probe1 connected), however, I put the setpoint at 225 and the blower is still showing 0%, so it seems probe one is only partially taking over the role of pit probe?
 
Told ya the LCD would be messed up :-P

I've sent you another try. It's not an easy change to just use a different probe for control apparently.
 
Bryan Mayland said:
Told ya the LCD would be messed up :-P

I've sent you another try. It's not an easy change to just use a different probe for control apparently.
Click to expand...

The latest version is working, Probe1 now runs the pit. The display on the HM LCD is fine for me, the web interface showing the pit probe as OFF is gonna be harder to get used to than the double display on the LCD...

The new MOSFET servo booster is working over a short cable, and the new stepped motion of the servo is just great, way better than the old super fast jerky motion on the servo. Gonna take it out to the pit and give it a try over the long CAT5 cable now.....

It's too late for pork, so I guess it's beef or chicken for dinner tonight..... lol
 
Good news, the MOSFET servo booster seems to be working just as good as my original version did. I'm running my roto damper over the same (long) CAT5 cable that makes the servo spazz out without a booster and so far it's been very stable. Not only is the servo solid, but the probes seem to be reading MUCH better, registering at lower temperatures and showing smoother response. Not sure if its your new low noise design on the HMv4.2 boards, or the new Voltage mode on the blower, probably a combo of both. Whatever it is I must say HATS OFF, best Heater Meter yet!

I will try to use it a bunch and continue feebdack, but I'm pretty sure you can drop that extra resistor from the board for the NPN version of the servo booster....
 
...been running the pit over the long CAT5 cable for 2 hours now, stellar performance persists! The servo motion is SO much better, super quiet, smooth and less "hyperactive". Temp graphs remain smoother than ever...

I don't know if it's just due to my experience with the HM at this point, but the 4.2.3 board seemed to build easier than the earlier versions I've assembled as well. Rotating the Mega and moving other solder joints further away from it was a good move. The HM and display mates with the rPi in a really nice compact solid package, you have to lean those two MOSFETS to one side a tiny bit to allow the rPi to mate evenly but that's pretty easy to figure out. The surface mount thermocouple soldering went way easier than I expected, although I would have never gotten it done without that cheap magnifying visor from Harbor Freight 'cause I simple couldn't see those tiny legs on the thermocouple amp without it.

I read your description of how to install the display, had a little bit of a hard time following it. I ended up taking 6 leg sections of header and soldering it to the HM board display header on both ends first, then pried the plastic parts off of the header leaving only the pins, then pushed the display up from behind until the boards were in contact with each other, then soldered the back side of the display in place. The legs do protrude out the back of the display a bit, but there is still plenty of clearance between them and the rPi so I saw no reason to trim them.
 
I left the HMv4.2.3 run over night (inside the house over the long CAT5 cable). Everything is still good today,temp graphs are super smooth. The low temp was only about 52 degrees but neither of the probes dropped off at all, with my HMv4.0 or HMv4.1 the probes would normally start dropping out below 70 degrees when running over this cable, so the probes are working MUCH better on the HMv4.2.3... I'm really pleased with it... When I get a chance I'm gonna throw the probes in a glass of ice water and see how low they go before they drop out.
So, Day 2 and I am still very impressed, no issues yet....
 
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