I acquired a batch of WT0490 wearable pdas with detachable scan head, so converted an application originally made for Windows Mobile (which has been running perfectly for several years) to run on the WT4090s. The devices use these versions:
Windows CE 5.0
EMDK 2.6
ASP.net CF 2.0
Since rollout I've seen some very frustrating behaviour, which seems to start happening after the devices have been operating a few days. Users are reporting the following error:
Unexpected error in application
SCAN_Enable
There doesnt seem to be any noticeable pattern, several devices will be working perfectly for a few days then suddenly this error will show. THen a few days and a few reboots later they work again.
All devices were taken right back to stock settings then our cabs deployed to them. All identical models. We've tried altering memory allocation, swapping scanner headers etc but there is no pattern.
The error seems to occur on load of the first form after login, the login screen displays a list of users in a dropdown with a password box so that part of the app works ok, it seems to be when the scanner is initialised that this failure happens.
I had 40 devices, now 30+ have gone down with this same issue so my gut is telling me its a software issue but as yet ive not been able to find out why.
We've tried warm boots, cold boots, complete reprovisionings as well. We have a couple of dev units that don't show the problem although they are not in regular use so maybe we just haven't seen the problem 'yet'.
I hope someone out there has had this issue and knows how to fix it.
Thanks in advance.
WT4090 was built by Motorola Solution enterprise business, now part of Zebra Technologies. The WT4090 is currently in EOS (End Of Sales) but is still supported by Zebra if you've a maintenance contract.
You can check if you've the latest OS version and fixes installed on the device looking on Zebra Technologies support website.
For question on how to develop for Zebra Technologies devices you can take a look at Launchpad, Zebra's developer community website.
It's Worth noting that these devices have detachable barcode scanners - so if the scanner is not correctly attached, you get a SCAN_Enable error.
If you don't release the scanner, you can also see this error as a previous form could have the scanner blocked.
You may also find you have the ScanWedge app running - this will also block the scanner so you cannot get it enabled. The EMDK needs exclusive access to the scanner to enable it.
Related
A couple of years ago I gave up developing Android apps because Samsung stopped persisting foreground services. This move by the leading Android platform killed all of my apps.
I'm familiar with dontkillmyapp.com but using all of those suggested interventions don't do the job.
Any time the phone user uses the "close all" option my foreground service gets killed immediately along with all the running apps. This is a common operation that I often use when poorly written stubborn apps won't quit. This happens regardless of any battery settings.
This posting is sort of a last check to see if anyone has come up with a solution to this problem.
I still don't understand why Samsung would do such a thing unless they are trying to push Android off their phones in favor of some new operating system they may be working on.
Upon upgrading to Big Sur (macOS 11.0.1), our app is now asking the user to grant permission to use Bluetooth. However, we are not running any bluetooth code to my knowledge. We do link to CoreBluetooth, but it's been like that for a long time, and this prompt has not appeared.
When running in Xcode 12.2 it does crash with this message:
2020-11-13 13:21:58.685610-0800 Fuze[31049:200367] [access] This app has crashed because it attempted to access privacy-sensitive data without a usage description. The app's Info.plist must contain an NSBluetoothAlwaysUsageDescription key with a string value explaining to the user how the app uses this data.
But to my knowledge, NSBluetoothAlwaysUsageDescription is only applicable for iOS devices.
I suspect this is something new with Big Sur, because the System Preferences UI for Security & Privacy -> Privacy, did not have a Bluetooth section in Catalina, and it does in Bug Sur. But the Apple documentation does not make mention of this key being applicable for macOS.
https://developer.apple.com/documentation/bundleresources/information_property_list/nsbluetoothalwaysusagedescription
So my questions are:
Is this key now applicable for macOS and we should have it, even though the documentation says it's only for other platforms, or is there a different key for bluetooth for macOS? I haven't found one.
Is there a way to control this prompting or not, because we aren't actually using the bluetooth code. We need the framework for a particular feature, but it's not applicable for many users, so it's confusing to ask permission for it right when the app launches.
Thank you!
I'm not confident about this, but I've been running into some Bluetooth on Big Sur strangeness today as well. In my case, I run a Bluetooth peripheral from the Terminal, and I was also recently prompted to provide the Terminal with Bluetooth permission (which I'd never seen before).
For testing purposes, you can try the "Privacy — Bluetooth Peripheral Usage Description" or "Privacy - Bluetooth Always Usage Description" - and see whether that resolves the crash (I assume it would). It's strange, as I didn't think either of these were required in the past - but it looks like Big Sur is definitely cracking down on permissions.
When you go to "Signing and Capabilities", if there is an option to enable "Hardware -> Bluetooth" in the "App Sandbox" - I would try that out too (you may also need to enable Location, but I can't recall). I'm curious if modifying that flag would change anything regarding permissions.
When you link to CoreBluetooth, are you using the API at all? Because the permission check should happen on the first API call. But, Bluetooth is weird, so it might kick in as soon as the app launches...
In thinking about it, I've actually never optionally used Bluetooth in an app - it's always initialized from app start, so I can't say when the permission check occurs.
I have been working with web-bluetooth for the past several months on iOS and ChromeOS without any problems. But today, I tried to run some of my examples on Windows for the first time, and to my surprise, most of the things I had implemented didn't work with Windows. I am able to successfully connect to my peripheral, but whenever I try reading or writing anything to a custom service with a custom characteristic, I get the error "GATT operation not authorized". I have tried looking around but there is no information anywhere about this.
I am including below the simplest example I have which is just for turning the LEDs on / off on an nrf52832 board. There is only one custom service and one custom characteristic implemented, the value of which controls the states of the LEDs. This works without any problems on Chromebooks and Macs but does not work on Windows. Here is the link to this simple project including the embedded code and the web-app.
https://github.com/shtarbanov/WebBluetooth-Feather-nRF52832/tree/master/LED%20Control
I have made two implementations of the same thing, one based on promises and another based on async-await located in the folders "WebApp (Async)" and "WebApp (Promises)", respectively. Both of those implementations work fine on Mac and Cromebook, but not on Windows.
It is a known issue that secure characteristics are not accessible using Web Bluetooth on Windows. On other platforms the pairing occurs automatically, but not on Windows. There is an issue tracking this:
https://bugs.chromium.org/p/chromium/issues/detail?id=960258
Stuck with this also and as for workaround i can recommend for windows platform to pair device firstly using windows itself and than to pair it via browser(as a workaround). Not much but hope this helps, at list a little.
P.S. it should be paired via windows only once, so PC will remember device, and than you can pair via browser as long as PC remembers device.
I am attempting to install Cubase Elements 10.5 'stay at home trial but fail to get any audio.
I have followed numerous guides online about shuffling various Gb files around (surely thats the installer job) but still nothing.
All audio mapping shows as connected.
When testing eg using the Production > Blues Rock Production (so its not even setup), for each Channel I get the error message:
The current preset or project was created with a previous version of HALion Sonic SE. If you modify the preset using new features of this trial version a previous version might not be able to load it or the preset might sound different
if I just click ok and load the project it seems to play, but no audio or output levels show.
I am getting nowhere with Steinburg 'Support', raised a support request and this is just ignored.
I have been trying to get this working for about a month and installed several times.
VST Connections
Audio Device and Driver
The application is in focus when it fails to provide audio, not sure where to make it play in background.
Screenshots of fault:
Chose a project as test, but when loading each of the channels shows this error,
I click ok to make it load:
Press play, no sound
but see it playing here:
Attach a screenshot of your VST connections in Cubase to help others diagnose your system.
Ensure you have latest drivers for your audio card etc.
Ensure your operating system (or any other background/foreground app) is not using the outputs you have selected in Cubase.
as they may not be multi-client.
ASIO compatible hardware is recommended.
Ensure background audio is enabled in Cubase if the application is not in focus.
Confirm that you have followed at least the steps above in any further replies. Specify your level of experience with computer audio in general, so that further information is relevant to you :-)
I am a .NET programmer who needs to port one good Desktop OTP system already at work to be used into cell phones. As far I know J2ME is the correct answer to do it. I'll appreciate any good advice about IDE, first steps, books or any other information.
Well, Eclipse IDE have good J2ME support, or so I've heard.
For api, read the javadocs:
http://java.sun.com/javame/reference/apis.jsp
You'll have to figure out which device you want to target, and grab its emulator.
Then, proceed making a hello world app with the aid of tutorials.
I would give NetBeans a try as well. Eclipse and NetBeans are very similar, but the differences can be night and day depending on your personal preferences. NetBeans also has great J2ME project support, and it is plug and play for any emulator of a device you may need to target, though I recommend sticking to the default or SonyEricsson's. Motorola's was always buggy and never reflected the device at all, and Nokia's was always sloooow.
Also, there are a ton of devices out there. Before you jump head first into this you should define a scope of exactly which devices you will need to target. This will have a huge impact on scheduling as porting is no small task.
Finally, just get your hands on the actual devices you need to target. Emulator is a good way to start, but there are always so many nuances and problems that pop up once you throw the app on the device that it's best to have your target devices from day one.