[Feature] Alarm auto re-arm


 

Bryan Mayland

TVWBB Hall of Fame
Alan Erickson said:
One other alarm question. On my old system when I was able to get it to work I would only get one alarm even if the temperatures went back to the "in control" range. In order to get another alarm I would have to go back into the web interface and "arm" it again. Is there someway to set things up so I'll automatically get an alarm without having to "re-arm" the alarm?
I agree with Alan's notion. That's why coming up in the next version, the alarm code is changed slightly so here's the head's up.

The new default behavior is that the alarms are silenced instead of disabled. To prevent the alarms from going off every time the temperature bounces back and forth across the threshold value, there's now going to be a hysteresis. The alarm now has to be inside the threshold by more than a degree before it "arms" and is available to sound.

Example: Your current temperature is 99.9, and you set the high alarm for 100 at this time. Your alarm is not armed yet and will not arm until is is a degree from the alarm threshold, that is below 99, say 98.9. Even if the temperature rises to 500 the alarm will not go off, as it was never armed.

Now assume the current temperature is 98.9, and you set the high alarm for 100. When it hits 100, the alarm will fire. Even if it drops back below 100, it will keep ringing until silenced (as it does now). Silencing the alarm by pressing a button on the HeaterMeter, unplugging the alarming probe, or opening the lid only silences the alarm. If the temperature drops below 99 again, the alarm will rearm, and then goes back over 100, the alarm fires again.

To clarify, the only way to actually disable an alarm is to either uncheck the "On" box in the config page, or to disable it from an alarm script.
Code:
# Silence the alarm and allow it to re-fire
al_set 0
# Disable the alarm and prevent it from re-firing
al_set -$al_thresh

It may sound a bit confusing but it works more like you'd expect, every time the temperature is in the "OK" range (more than a degree from the alarm point) then passes the alarm point, the alarm goes off. You've just got to remember you can't set the alarm while the current temperature is within a degree of where you want to set the alarm.
 
Thanks Bryan. I had visions of myself stumbling around at 3 a.m. in the morning and forgetting to reset an alarm after stoking the fire. ;)
 
You may laugh but I forgot to disable the alarms last night before I went to bed which led to be me stumbling around at 2:30am this morning to go turn off the alarm which had re-armed. If I were smart I would have just grabbed my phone and turned it off from the website but I was confused and tired. Apparently it works pretty well!

I just have a little more testing to go, the avr hex file should be website tonight.
 
What would be the easiest way to make alarm not re-arm until 5 degrees above / below alarm set point? My cooker fluctuates easily 2-3 degrees and when an alarm goes off it re-arms multiple times within a few minutes. I'm using a large stick burner and the 1 degree hysteresis is just too tight of a tolerence for me. Thanks!!
 

 

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