The Development Log


 
Well, first of all, I don't think anyone was suggesting adding a CAT5 jack and then removing the individual probe jacks... The probe jacks will always remain there, the jacks on the end of the CAT5 cable would be an optional way to connect the grill through a very long cable if desired. I have run a CAT5 cable from my grill into my basement and up into one of my kitchen cabinets, so when I do winter cooking I can just pull the CAT5 out of the cabinet plug in the HM and I am good to go, no electronics or power needed outside by the grill. I have tested this and it works, though I have had some interference issues that make the temp readings a little rocky, I will be experimenting with some caps to try and smooth that out this weekend.
To me this seems like a no brainer, you loose nothing and gain the option to run the HM far away from the pit. Another scenario... When I do away from home cooks I always have to setup the smoker where I can get power, with the CAT5 cable I can set the smoker wherever I want then run the CAT5 cable to wherever the power is and leave my HM (and laptop connected to the HM via LAN cable) near the electricity where it is likely protected from weather. Before I would have run extension cords, and had probe leads all over and take the chance that someone will trip over a wire and take out my HM, or worse, tip over the grill. Think of the recent thread "It was the best of times, it was the worst of times"
At any rate, I will conform the CAT5 wiring on my servo damper to match the RJ11 wiring and can either use a phone cable (cause a phone cable WILL fit into a CAT5 jack and work for 2 to 6 wires) or I can make a custom cable with a CAT5 jack on one end and a phone jack on the other...
 
Got notice today that my HeaterMeter v4.1.0 boards shipped from OSH Park. So exciting it is when new hardware is on its way. I had been putting off placing a mouser order until the time got close so I could "max out" my order with anything else I might need to have on hand. It must have worked because I just bought a ton of stuff. Surface mount capacitors are only 2 cents? I'll take 50 even though I only need 2! I even bought 20 extra resistors by mistake for 28 cents.

Also picked up a part which might be a good replacement for one of the Digikey parts in the eternal quest to get everything down to 1 vendor. $2.60 for a 26 pin connector though, that makes me think I am in the wrong business.

After giving it more thought, I am only 60% sure about the v4.1 board having an RJ11 jack. I can say that if the board is flawless it will definitely be RJ11. If I need to make changes anyway, I'll have to think about it more seriously. I ordered RJ45 jacks just in case.
 
I'm eager to hear how the new board works out.....

I've been meaning to comment.... I really like the way the graph will restore itself after the unit is power cycled, however, this can lead to a very long graph which can make the Auto Scale mode look kinda odd, showing the data from a whole day with yesterdays cook and today's in the same graph. I tend to go in and reset the graph data to get the auto scale to display properly each day, so it would be nice to have a link on the main page to reset the graph if possible. If you could drag and select a time period on the bottom graph and then delete that selection that would be even better, but a simple convenient reset graph button would be fine, if possible...
 
I agree. However, it won't show anything if the last graph was over 24 hours ago so I don't think it is a common problem in normal use. It's on my todo list for the home screen redesign though and will definitely be in there because I reset my database all the time. The "reset" I mean. Clipping the database is also on my todo list with a drag and select action but that's a lot harder so it will be further off. Timeline? Hopefully in the next year.
 
Another thing I just noticed for the first time... With the temperature scale on the left side of the graph and the blower speed scale on the right, the food probe graph(s) dead end against the blower speed scale which really have no correlation. It would be nice to have the temp scale on the right side instead, so the food probe graph lines end on the temperature scale where it will provide some additional visual reference to your food temperature...
 
I'm off to California from Thursday to Monday but as luck would have it, Mouser delivered my parts today to go with the boards I received Monday. Bad news is they don't work.

-- Major: I reversed the pinout of the Pi header when I attached the switch that was eventually going to be for the switch that would allow you to boot to different configurations. This shorts 3V3 to ground and prevents anything from powering up. Luckily no damage was caused.

-- Minor: The 5V capacitor is too tall and needs a smaller part or to be moved or be installed in a bent over configuration.

-- Unknown: The servo doesn't work at all. The AVR is putting out a constant 3V3 instead of a pulse and I don't know why. There could be a short somewhere that is bridging power to it, but continuity says no. Seems like a software problem but both the bundled and the trunk from online repository show this. The servo normally works, right? EDIT: FIXED

-- Not good: The RJ11 jack is too tall by a couple of mm. The board won't lay flat inside a case. This is probably an 80% chance that they'll be swapped for RJ45s now because the shieldless RJ45 jacks I ordered are a tiny bit smaller. I need to do some measuring before I know they'll fit.

-- Good: New beeper booster means more ear-splitting decibels for developers sitting right next to it.

-- Good: Blower shared ground is working just fine. I want to experiment with different capacitors now because it seems more sensitive.

-- Good: The M3 screws accommodate M3 screws. Sometimes you never can tell.

-- Good: It works other than the obvious problems. Booted right up after I fixed the short and does as well as a v4.0 board.

I'll start working on the v4.1.1 next week.

EDIT: Fixed the servo problem.
 
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v4.1.1
-- Properly connected servo to pin 14.
-- Moved 5V capacitor somewhere it won't contact the Pi.
-- Replaced RJ11 with RJ45. Inner pair is 12V/Gnd which allows for 2 pin telephone cables if only blower is used, 4 pin telephone for servo.
-- Removed 3V3 passthrough to Pi. HeaterMeter's 3V3 is now isolated so the 3V3 regulator will always be installed, eliminating the confusion. I also connect 5V to only the original RPi 5V pin rather than all pins that carry 5V.
-- Extended board depth 0.025" to accommodate the RJ45 width. Moved all components 0.05" down to make finished device 0.025" smaller

3D Printed Case Designers As you can see there's some wiggle room for the screw holes. The bottom left is 0.5",0.15", bottom right is -0.6" (from right),0.15". I'll send this in tomorrow but if there's any better placement, like 0.45" for the left and -0.65" for the right let me know. I placed them on even-ish inch spaces but let me know if you think you'd have an easier time if they were further from the ATmega chip or the ethernet socket.
 
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It's tight but should be ok. I don't think that moving them will change much. What did you say the diameter of the holes are? 1/8"?

Even if the holes turn out to be problematic, this board design is flexible in terms of case design because of the 2 walls that are completely free of inputs and outputs.

Nice work as always Bryan.
 
Tom Kole said:
It's tight but should be ok. I don't think that moving them will change much. What did you say the diameter of the holes are? 1/8"?
Click to expand...
Yeah they're 0.128" (3.2512mm) diameter and an M3 screw drops right through them. I can make them a full 3.4mm if you'd prefer. I picked 0.128" because that's the same size as the RJ11/RJ45 hole drills and I try to keep my drill bit count to a minimum.
 
That's plenty of clearance. I'm ready to start modeling as soon as these are available or as soon as you release a schematic.
 
Suggestion for development:

It would be cool to get a pushed notification SMS/Email on some regular basis. Right now I Would have to login to the webpage to see the current temps however if I am not home or something it would be great to say every 15 minutes push me the current status?

Also is more probes not an option?

Thanks,

Neil
 
I can see that being useful for some. I'll put it on the todo list.

More probes sort of can possibly be an option, but you'd have to redesign quite a bit of the UI and build your own HeaterMeter firmware. You can only add 1 more though, on account of there's only 1 ADC channel not being used at the moment, so I'm not sure it is worth the effort.
 
When looking at the design and schematics when I was trying to debug my first heatermeter I noticed a free ADC channel and was curious why it wasn't used in the first please? I was going to build another heatermeter to have more probes. I like to monitor a lot of things! Software wise I cant' speak about but from a hardware perspective why not utilize the last ADC channel?
 
The original HeaterMeter was drawn up with 1 pit probe, 1 food probe. Before I built it I thought "Why not have *two* food probes? How sweet would that be?". As I was building it I thought "Why don't I put a thermistor on one port and have it be like an Ambient sensor? How cool is that?". Then I designed the software and website around that. I still feel that two food probes is plenty for 90%, three seems like it should cover 99.9%. Even with just four probes it seems the wires get all tangly and the web UI is complex enough without adding 25% more information to it.

If four probes isn't enough, would five probes be enough? Probably not :)
 
Bryan Mayland said:
The original HeaterMeter was drawn up with 1 pit probe, 1 food probe. Before I built it I thought "Why not have *two* food probes? How sweet would that be?". As I was building it I thought "Why don't I put a thermistor on one port and have it be like an Ambient sensor? How cool is that?". Then I designed the software and website around that. I still feel that two food probes is plenty for 90%, three seems like it should cover 99.9%. Even with just four probes it seems the wires get all tangly and the web UI is complex enough without adding 25% more information to it.

If four probes isn't enough, would five probes be enough? Probably not :)
Click to expand...

Yes it is a slippery slope. I have a stoker and I am happy to replace it with the heatermeter. The stoker will split and do a ridiculous number of probes (I think unlimited). The probes for stoker are super nice but use the large plug and they light up or something. Ultimately I am using the heatermeter myself as a glorified wifi temp sensor. I would like to keep an eye on things while I sleep and my bedroom is too far for bluetooth or the maverick with concrete walls down here in SWFL. I have a big smoker and could be cooking a bunch of different things or a couple different briskets and want to keep an eye on them hence my desire for more :)

Another possible suggestion that the stoker does is that is tweets. It will periodically tweet with the supertweet api so you can monitor your cooks. http://www.supertweet.net/

Might be worth considering?

Thanks,

Neil
 
I've found supertweet to be pretty unreliable. I was using it for a while before I could fix my apps to use the new API and Oauth. I'm trying to get tweepy working on OpenWrt but I'm not having much luck.
 
HeaterMeter v4.1.1 boards shipped today. Last time it took just 2 days to get the boards all the way across the country, so hopefully I'll have them to build by the weekend. Let's hope I did it right this time and the RJ45 jack is an OK height.

I've also noticed that mouser is out of ATmega328P-PUs until January which is a shame because it is time to pick up another 10 and some LCDs. Two shipments hooooooooo!
 
NeilHeuer said:
Yes it is a slippery slope. I have a stoker and I am happy to replace it with the heatermeter. The stoker will split and do a ridiculous number of probes (I think unlimited). The probes for stoker are super nice but use the large plug and they light up or something. Ultimately I am using the heatermeter myself as a glorified wifi temp sensor. I would like to keep an eye on things while I sleep and my bedroom is too far for bluetooth or the maverick with concrete walls down here in SWFL. I have a big smoker and could be cooking a bunch of different things or a couple different briskets and want to keep an eye on them hence my desire for more :)

Another possible suggestion that the stoker does is that is tweets. It will periodically tweet with the supertweet api so you can monitor your cooks. http://www.supertweet.net/

Might be worth considering?

Thanks,

Neil
Click to expand...

You could build a second HM to monitor more items on the smoker. Just bookmark them both in your browser and flip between them at will. As a bonus, you get to build a second HM! Optionally, build a new HM when the new hardware is released then use the "old" one as a monitoring unit...
 
On the new 4.1 I noticed that the parts are slighty different. I have all the parts for a 4.0 and was wondering if the LCD would work with the 4.1 as it was a different P/N. Other then that there is an extra ent, the mosfet is different, and there are several extra resistors for anybody else that's looking.

4.1 4.0
LCD - 763-0216K1Z-FSPG-GBW 763-0216K1Z-NSW-FBW
ENT - 523-RJHSE-5080
MFT - 512-FQU11P06TU
RES - 660-MF1/4DC1002F QTY 1
660-MF1/4DC2201F - QTY 1
 
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