Hello from UConn, Storrs Connecticut

[jonesrt]

Just received a pair of 2.5inch NaI detectors and a GS-Neutron-III from Gammaspectacular, eager to get underway with calibration and first measurements. First task is to measure the minimum background level of the GS-neutron. Have been running it for several days now with AtomSwift on my Chromebook, and seeing about 1.8-2.2 CPM in my lab environment, would like to measure that level much more accurately but the Bluetooth connection keeps dropping after a random amount of time, sometimes after just 6 hours and sometimes after 24 hours or so, but never running continuously for days at a time like I would wish. Obvious things have been ruled out:
1) battery (shown on meter) is full-bars
2) Chromebook is plugged in, power-always-on mode, screen blanking disabled, etc. etc.
3) immediately reconnects if I turn off Bluetooth, stop, and restart AtomSwift
4) distance from chromebook to GS-neutron device is 3 inches
I am not a windows user, although I am familiar with the Microsoft product, and I do not own a Mac or an iphone. Android and Linux are my platforms of choice at the moment. Any advice to diagnose and fix the dropped connections would be appreciated.
-Richard Jones

[Sesselmann]

Richard,

Welcome to the forum, and thanks for your questions.

I haven't had this issue before, suspect it is more likely to be the Chromebook than the neutron detector, but I will bring it to the attention of Max and get him to reply, the bluetooth circuit and AtomSwift is his work.

Steven

[Madmax]

Hi Richard,
First of all, don't worry about Bluetooth connection during long measurement, just start measurement from Atom Swift app and you can go away with your Android device and return when needed to check the result. GS-neutron don't need to communicate over Bluetooth during measurement process.
Android system can terminate Bluetooth communication process for unknown reason, Atom Swift app restarts it if terminated. Usually the less free memory available to Android - the higher probability of process termination.
Also some of Android devices have the same chipset for work with Bluetooth and Wi-fi, high data loads on Wi-fi can interfere with Bluetooth communication.
All voltages needed in GS-neutron are stabilized, and not depended on battery voltage until internal battery meter will show zero in the app, don't worry about this.

Maxim

[jonesrt]

Hello Maxim,

Thank you for your response to my questions. If you don't mind, here are some follow up questions on your answers.
1. What is happening is that the Bluetooth connection locks up, and the Atom Swift app says "Disconnected" in the place where it normally shows the IP address of the device. The app is not hung. I can exit using the exit button just fine. If I restart it, the init finds the device on bluetooth and lists it on the screen, but when I click on it, the connection does not establish. It just cycles forever trying to establish. The only way to recover is to TURN OFF Bluetooth and turn it on again. I do not need to exit the app, just turn Bluetooth off on the Chromebook and on again, and then initiate the Search (Settings->Rescan) again on the app, then select the listed Atom device. It immediately reconnects and starts up again.
2. It takes a random amount of time 1-6 hours typically, for the lockup to occur.
3. Identical behavior on two Chromebooks, different manufacturers and vintage hardware, same symptoms.
2. To investigate this further, it would be helpful to have the source code for Atom Swift. Is it available on GitHub? I see a project named /atom/ide/swift but I am not sure that is the current version I have from GS, which is shown as v0.9.3/8 on the gui.
3. I do not have any wifi traffic to my chromebook to speak of. Total bytes per hour to the Chromebook is a few kb. I removed the RF mouse so there are no other wireless devices attached, just the wifi and Bluetooth, and no Bluetooth devices are paired to it.
4. You say, "you can go away with your Android device and return when needed to check the result. GS-neutron don't need to communicate over Bluetooth during measurement process." but when I come back and connect again, there is no record of the measurements per hour that occurred while the Bluetooth was stuck. I look in the csv files, but they stop when the connection hangs and resume when the connection recovers. Is there some way to get these data back?

I was away on a research trip for a week, and when I returned I only had 1 hour of data recorded, all of the rest of the data had been lost. The battery was still ok however, and I was able to reconnect by cycling the Bluetooth on the Chromebook. But still none of the lost data are showing up, just whatever was recorded up to the hang time. Thanks for any steps you might give me on how to proceed. I am a fairly experienced programmer (rjones30 on GitHub) and I have some success in writing / debugging firmware (eg. Xylinx Spartan designs). Hopefully that will not be needed to fix this issue.

-Richard Jones