ICelcius loses connection

[Andy]

Hello Danny, and others with experience using Roastmaster with iCelcius,
I've been having a problem with iCelcius losing connection with Roastmaster between roasts. It was happening occasionally but seems to be happening more frequently. Tonight I had to reboot my ipad between each of 4 roasts to get iCelcius back. Does anyone have an idea what is going on and what I can do to prevent it?

[Danny Hall]

Hi Andy

Thermistor style probes can go bad over time, so I wonder if this could be a probe that is shorting out and causing a disconnect as it cools and the internal metals contract after a roast.

On the software side, Roastmaster polls every 15 seconds, and shuts down connections to probes if they are not currently in use by either a roast in progress, or a view that's reporting their temperature (either an idle roast console view or probe details view). This preserves battery life, since probe connections can put a big drain on the battery.

One good way to tell if this is a software problem or hardware problem is to launch Roastmaster, then open the probe details view in Utilities, with the iCelsius at room temperature. Make sure it starts reporting temperatures, then, "Dismiss" that view. Wait at least 15 seconds, then open it again. It should display nothing for a split-second, then begin reporting temperatures. Try this a few times and see if you can reproduce the problem outside of a roast.

Please let me know what you discover and we'll go from there.

[Andy]

I did the Utilities test a few times and it performed exactly as you said each time. If I understand you, maybe the solution for me is to unplug the probe between roasts, especially if I may not begin the next roast right away.

[Danny Hall]

Hmmm... that suggests that the problem is probably outside of Roastmaster. Not 100% of course, but the same code runs to start/stop probe functioning, regardless of whether it's being run at the behest of the roasting console for a roast or just that simple probe details view.

Since you mentioned restarting your device, one thing to note... when you tap the home button to quit the app, it doesn't actually quit - it just transitions to a background "idle" state. If a probe is sampling data for a roast in progress (not just displaying its temperature before or after the roast), Roastmaster will continue to actually run in the background, otherwise it just goes dormant. You can physically terminate Roastmaster's execution entirely by tapping the home button, then double-tapping it again to see the background apps, then swiping up on Roastmaster's icon/screenshot. That should have the same net effect on Roastmaster that a complete device reboot would - it would clear out all Roastmaster memory, and the next launch would be fresh. There is nothing I can think of that a complete restart of iOS would gain for Roastmaster's functioning, besides a little time for the probe to heat or cool and resolve the electrical shortage, IF that is in fact the issue.

But before we jump to that conclusion, another thought: the newer iCelsius SDK versions will auto-launch the iCelsius brand app when you connect the probe. This could be due to functionality that became available in iOS 7.x - not sure, but that might explain why you've never seen this before if you've recently upgraded. When their app auto-launches, most folks will just tap the home button to (assumedly) quit it, then launch Roastmaster and perform a roast. Here's the kicker - the iCelsius SDK (sometimes) does not like sharing the probe between two apps. If the iCelsius app is open on the device (even in the background) it can often commandeer the probe, and Roastmaster will be unable to connect to it until it relinquishes its lock on the probe. Since a restart seems to help you, make sure their app is not open in the background. If so, remove it from the background tasks in the manner described above. Note: Once their app "commandeers" a probe, Roastmaster might need to be restarted in the same manner to get the SDK to realize the lock on the probe has been released.

If that doesn't resolve it, it might be helpful to conduct a few dummy roasts with the probe at room temperature. Just let them run the normal length of one of your roasts, then conclude them in Roastmaster and see if you experience the same connectivity problem. That will help rule out a short in the probe.

Please keep me posted. I don't recall seeing the "commandeering" issue before the current version of their SDK, and a lot of folks new to data logging have a similar problem when the first connect the probe, so I'd like to help you get this resolved, not only for your benefit, but for my knowledge as well.

Thanks Andy!

[Andy]

the newer iCelsius SDK versions will auto-launch the iCelsius brand app when you connect the probe

I have feeling that may be the problem, because I often switch to the iCelcius app to monitor cooling. (Cooling occurs in the "roast chamber" of the popper -- I just switch off the the heat.)

[Danny Hall]

Ahhh - hopefully that's it. I didn't mention it before because I know we've talked, so I figured that would have already come up by now. Then I realized that behavior could have been introduced by an iOS update.

Let me know.

[Andy]

I tried re-establishing iCelcius connection by closing and re opening Roastmaster as you describe below, and that works. (This is my only apple device and iOS still throws me occasionally.) Anyway, now that I know how to get the connection back, I am good. Cheers!

[Danny Hall]

Thanks for letting me know. I've posed the question to the folks at iCelsius. It seems that their app should relinquish control when it goes to the background, or that their SDK should honor more than one connection at a time. It's been frustrating for a lot of users.