Introducing Ramp Mode in a snapshot near you


 

Bryan Mayland

TVWBB Hall of Fame
This feature has been requested a lot and I've always thought it was a great idea. The concept is that as your meat approaches doneness, the pit temperature will ramp down slowly so that when the meat is done, the pit is at the same temperature as the meat and therefore can "hold" indefinitely without overcooking. We'll have to see in practice how that works which is where you HeateMeterers come in.

New on the Alarms page is a section called Ramp Mode where you enter which probe to track, when to start ramp mode, and where to end it.


In practice it looks like this. When the "watched" probe temperature passes the "trigger temperature", the setpoint is proportionally lowered from the original setpoint down toward the "target temperature". Here, the trigger temperature is 180 and the target is 200. There's also an indicator on the home page that shows that ramp mode is active, with the start setpoint and the target temperature. The color can be changed by overriding the CSS class "ramp".


Ramp mode does persist across reboots! So if your ramp ins't complete and you pull the plug, it will still be in ramp mode when you plug it back in next week. The easy way to disable ramp mode is to set a setpoint so I don't think this will be a problem and guarantees that the ramp mode isn't reset by a momentary power glitch. Ramp mode automatically ends when the watch temperature is within 1 degree of the target. Also, the ramp setpoint is only updated once per minute, because writing a new setpoint every second just wastes EEPROM writes.

A big question on my mind is if this will actually work. If you ramp down the temperature, there's a chance that the food will never reach the target temperature, or that it will reach the target temperature somewhere in 2018. When I tried to test it yesterday ramping 180->200 = 225->200, I got about to 190 food / 212 setpoint before I had to pull it and stick it in the oven because I was running out of time. I'm interested to see what works for everyone else. Maybe 190 ramp trigger would be a better start?

Finally, "Ramp Mode" is pretty boring sounding so I might jazz it up with a trademarkable name.
-- Meat is Brown, Slowly Shut It Down Mode
-- Dwindle Fire
-- Gentle Butt Holding Mode
-- American Magoo's Perfi-done

The feature is available in the snapshot firmware but only the linkmeter package should be needed if you're already on a snapshot.
 
Awesome, I'll have to give it a try.
Since there is no field for the steps does the HM somehow calculate what size the steps should be? In your example your meat needs to go up 20 degrees while the pit drops 25 degrees, so the pit needs to drop a little more than 1F for ever degree the meat temp rises, nearly 1:1 ratio. But if you were to have set the trigger point at 190 the meat would only need to raise 10F while the pit had to drop 25F, so a 2.5:1 ratio, in that case the temp would have to drop 2.5F for every 1F the meat temp goes up. So by entering the start temp and the done temp does the HM automatically determine the proper size of steps to take?
 
I guess I'm finally getting the HM software thing down, because I went exactly to right page to upload/install the linkmeter package... Flashing firmware/software is still one of the more confusing aspects of the HM, even for a guy that's been around the HM block a few times. There's three places to update:

Config/Linkmeter/AVR Firmware: where you get the program that goes on the ATMega (AKA AVR) on the HM board

Config/System/Backup / Flash Firmware: where you load a .gz image that will update the software on the SDCard that loads Linkmeter the rPi

Config/System/Software: where you can install individual packages (.ipk) to the linkmeter system on the SDCard that loads on the rPi

This is all pretty confusing... It would be nice if perhaps all the update stuff was under one tab, or at least some explanation given about what you are actually updating on each update page, and perhaps include a little nugget of information on each update page to lead someone to the other places to update the system. Something to make it more clear that you are not updating EVERYTHING when you update one thing or the other.
 
Bryan,
I think you should put the Ramp Mode box right under the Alarm Settings box on the Alarms page rather than down at the bottom. Reason being, the Email and SMS settings are "set and forget" type of settings, once you've got it working you shouldn't have to mess with it again. The Ramp Mode settings are something you will mess with while you are setting your meat alarms so I think it should be placed up by the Alarm Settings and above the "set and forget" settings....
 
Bryan,
I think you should put the Ramp Mode box right under the Alarm Settings box on the Alarms page rather than down at the bottom. Reason being, the Email and SMS settings are "set and forget" type of settings, once you've got it working you shouldn't have to mess with it again. The Ramp Mode settings are something you will mess with while you are setting your meat alarms so I think it should be placed up by the Alarm Settings and above the "set and forget" settings....
You're right, I'll move it up.

Regarding the 3 different firmwares, it can be a little confusing, but if you flash the Config/System/Backup / Flash Firmware firmware, you get all 3 so that's why I always link that first. It takes the longest though, so optimally you can just flash what you need and save a couple minutes.
 
What are the little white circles? I don't have ramps enabled and they are showing up but never did before.
 
It is something new! It shows the high and low peaks of the temperature
emot-v.gif


They're generated by the peaks module, which is needed by the autotuner, which isn't working but can be used for manual PID tuning. I'm not sure if they'll stay in for release or not.
 
It would be nice to be able to turn them off, only for the fact that the added stream data causes probs with the Pit Meter app.
 
The Pit Meter app needs to get its **** together! I said it when it first came out, to parse the JSON instead of trying to regex it because extra data will break it, but nooooo does anyone listen to me? The problem is that the data is always going to be there, the question is if the web page displays it so Pit Meter will always be broken.
 
It is something new! It shows the high and low peaks of the temperature
emot-v.gif


They're generated by the peaks module, which is needed by the autotuner, which isn't working but can be used for manual PID tuning. I'm not sure if they'll stay in for release or not.
Haha got ya. I was just trying to figure out what was going on with my cook yesterday; it was all over the place. I was doing jerky at 190* but the pit temp readings all the sudden would drop suddenly and quickly, enough so to activate lid mode. I know the temperature wasn't falling that quickly but for some reason that's what the thermocouple was reporting. It was causing the smoker to run much hotter I think because a fair about of the jerky burnt, especially on the lower rack.
Here is a picture, the biggest temp drop was me actually removing the lid/probe.
k9hyj7.jpg
 
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The ramp mode sounds pretty cool. What is the best way to get it on a pre-existing HM? If I re-flash the card will it kill all my settings and archives? Or is there a more 'gentle' way to update the firmware?
 
I used the ramp mode for the first time last night and it went pretty well. I was surprised to see it actually ramp the setpoint UP a little bit after I had lifted the lid a bit too long on a couple occasions (grabbing samples!) and caused some overshoot.
RampMode.jpg


I was running the RD3 in damper only mode (Blower @ Max Only) and it did very well tracking the ramped setpoint, would have been much better if I hadn't opened the lid so much, it was tracking pretty sweet until I popped the lid that last time. I ultimately yanked the small piece of a boston butt off before it hit the 200F hold temp, it was close to temp and done but could definately have held for quite a while at 200F in been great too...

I think it's a great feature, but go into it knowing that this is going to extend your cook time on an already long low and slow cook. I think it could result in a better cook though, if you set the ramping down to start a little after a large piece of meat (shoulder/brisket) exits the stall it will slow down that steep-ish rise that generally happens right about then, and allow more time for the fat and connective tissue to melt away at a lower temp and tenderize and flavor the meat.

If you've got your grill dialed in to the point you can run a low and slow cook for an extended period the ramp mode should work out perfect so you can set a large piece of meat on the grill before you go to bed and have it holding in the grill at the done temp the next afternoon for a picnic or whatever.


PS: I noticed when I pulled the probe out of the meat the ramp function jumped the temp right to 200F. I am wondering if you can code it so if the meat probe temp drops radically (like 50F) it will change the setpoint to something very low, like 0F to shut the pit down? Or make that an option you can check in the ramp mode setup, "shut down pit when meat is removed?" It just seems to me when you pull that probe you're done, and boxy robot should shut things down....
 
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In that circumstance, if it were to shutdown, would it be able to resume if it were an accident, or you had pulled the probe for any other reason?
 
PS: I noticed when I pulled the probe out of the meat the ramp function jumped the temp right to 200F. I am wondering if you can code it so if the meat probe temp drops radically (like 50F) it will change the setpoint to something very low, like 0F to shut the pit down? Or make that an option you can check in the ramp mode setup, "shut down pit when meat is removed?" It just seems to me when you pull that probe you're done, and boxy robot should shut things down....
That's probably not going to happen. I see too much of a chance of that going awry, like you're pulling out the meat to foil it or something and have to remove the probe for a second and uh oh we just turned off your grill and you didn't notice.

If you want Boxy Robot to automatically shut down the Pit, pull the Pit probe out of the jack. It will set the output to 0% and put out your fire! Oh I guess you have all your probes plugged in at the damper end that's right. Welp pull the ethernet cable out and give the damper a turn until it is closed? You could also make a low food alarm that sets the setpoint to a low value. It won't trigger until after the food passes it by a degree the first time and then drops back below that.
 
I generally turn the pit over to manual mode when done cooking and leave the RD plugged in with the pit probe attached. (I like to keep the RD running for durability testing)
This time I just happened to forget to set manual mode when cooking was done and when I noticed it jumped right to 200F that made me think "would be nice if it had jumped to off".... but I understand your reasoning.... In practice though, my pit jumped right to the hold temp when I pulled the probe, so if you pull the probe by accident while foiling or whatever you're gonna kill your ramping anyway...
A "Resume Ramp" function would be nice in either circumstance, maybe clickable text like lid mode?
 
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In practice though, my pit jumped right to the hold temp when I pulled the probe, so if you pull the probe by accident while foiling or whatever you're gonna kill your ramping anyway...
That sounds like a bug I'll have to investigate. The ramp mode should only shut off if the temp reaches the target, or the setpoint is changed.
A "Resume Ramp" function would be nice in either circumstance, maybe clickable text like lid mode?
That would be the opposite, the text is only there if you're in ramp mode. Making it clickable would be to easy to deactivate it by mistake, especially when viewing the site on a touchscreen display. There shouldn't be any need to resume a ramp though, unless there's a bug that's turning it off too soon.
 

 

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