Serial Communication on Windows 7 via Bluetooth has intermittent data loss - windows

Currently I'm working on a portal device, which communicates with Windows via bluetooth serial communication.
It works fine on windows 10.
But on windows 7, things get strange, the communication is not stable, sometimes it runs well for a whole day, sometimes it lose data frequently. The bluetooth driver version on two platforms is the same. I have no idea how to solve it.
Are there any reasons?

Related

Windows 8.1 Bluetooth Low Energy Behavior

I'm looking into programming Bluetooh Low Energy on Windows 8.1 and have a few questions about its behavior on auto-reconnecting to BLE devices after the connection is termiated:
How long will this auto-reconnect feature timed out? Or is it as long as you subscribe to BLE notifications and attempt to read/write data to it?
Will it reconnect if I restart Windows and my application?
How many devices can Windows remember to reconnect? Is it as many as the number of devices my app can connect to?
Where did you read about auto-connecting algorithm for Bluetooth devices in Windows 8.1. As far as I know, it is not possible to perform any kind of auto-connection, so all connection establishment has to be done manually in Windows 8.1 Bluetooth settings.
If your device is in connected state and you restart your PC for some reason, it will still show your device in the list but as "Not Connected" state. So you manually have to remove the device, and then pair it again.
I made a test, where I connected to two devices and read notifications from them both at the same time. What do you mean by app ?. A Smartphone application or ?.
All in all there is a lack of efficiency using Windows 8.1 for BLE applications, since all scanning and connection establishment functionalities have to be done in Windows 8.1 settings rather than in your Windows application, which restricts some important algorithms like auto-connection based on RSSI values and so on.

Maintaining a Windows Bluetooth Connection

I'm manufacturing a device that connects to my computer using Bluetooth and then a desktop Java app uses the Bluetooth connection to send serial data to the device which is then displayed.
When I try to connect my device to windows 7 it successfully finds and pairs with it creating a Bluetooth link on a COM port. This link can then be used by a serial prompt (used for testing) or my Java application. It works initially however soon after windows drops the connection and the only way to reconnect is to delete the device within devices and printers and then reconnect.
This seems to be a known problem with windows bluetooth so I decieded to use a third party Bluetooth application. I downloaded and tried Toshiba's Bluetooth Stack and it was able to add a Bluetooth device and keep a stable connection which works great however this only works for Toshiba computers without getting a cracked version.
This device is commercial and can't be sold with cracked versions of software. Has anybody experienced the same problems or not in other operating systems and has any solutions of advice as that would be a tremendous help.
This is not a good idea/method to use the COM ports generated by Windows, it's not working fine and not reliable in any scenario ; you should use Bluetooth Sockets instead.
Using Toshiba or Widcomm or BleuSoleil won't help: under Win7, all dongles are now trying to use the Microsoft Stack, not their own implementation.

TDS NOMAD windows CE5.0 device connects more than two USB devices

I have a TDS Nomad running windows CE 5.0 system. It has a USB host port. I have connected to the manufacture and ask if nomad can connect to more than 1 USB devices via USB hub (can connect to 7 USB devices, designed for windows ), they said they haven't tested to connect more than one USB device. If more than one devices is connected to nomad, there mightbe resource conflict.
The nomad works well with one USB device connect to it individually.
But I have a console application debugging in nomad using visual studio2005 and active sync.
I need to talk to both USB devices. Therefore I have to use USB hub. But it doesn't work most of the time. I think the drivers of two USB devices are all correctly installed on nomad.
But what I want to ask, is that has anyone tried to connect more than one USB device to windows CE product via USB hub and both of them works well ?
I'm slightly confused. here. You say the device has USB host and you want to connect more than one client device through a hub. This is definitely supported by the OS, and I've done this with several devices from several manufacturers, though never with a Nomad. Not sure what the OEM is talking about with "resource conflicts" as the USB spec itself allows for multiple devices (kind of the whole point behind a "bus").
But you say that your second "device" is the debugger. That isn't a USB Host connection from the device perspective, that's a USB Client connection, and it typically uses completely different hardware and drivers for that connection. Can a device have both a host and a client connection? Again, yes I've done this with many devices (but not a Nomad) and the OS fully supports it.
Now maybe this is USB OTG hardware (though back in the 5.0 days I doubt it) and the OEM didn't do the design well to handle a client and a host at the same time. Maybe the physical hardware is laid out poorly or the OAL portion of their USB driver is poorly done and can't route properly through a hub properly (I've definitely seen that before). Hard to say.
A USB Analyzer would tell you a whole lot about what's actually happening and where the problem is, but it is definitely a supported scenario by both the USB spec and the OS. If it's failing, it's a manufacturer/device-specific problem.

Connect multiple (two) windows phones to the computer at the same time and develop

I'm developing an app on windows phone that simply can't work without at least two phones (Two phones need to see each other through wireless network and act together. And I use an API that is not properly implemented on emulator).
Unplug the first one and plug in another repeatedly as I'm modifying the code and watching changes on the phones is painful.
Is it possible that I connect two windows phones, and make them work, at the same time?
Unfortunately it's not possible to connect multiple phones to the same PC at once. The connection used by Zune (or WPConnect) only works with one device at a time.
I've been in a similar situation to you (debugging software on multiple phones at the same time--as they talk to each other) but there's no way round this.

Windows Phone - Application crashes when disconnected from PC

Whenever I disconnect my Windows Phone from PC (connected through USB) and if my application is running, my application hangs for sometime and then application crashes.
Does anyone experienced same behavior? I guess switching for PC connection to Wi-Fi/GPRS is causing the issue.
the windows Phone Requires that you Safely Remove hardware first, after a few times when i started Development on the windows phone i did the same and Ended up getting a new Phone. So plainly put, try to Safely Remove and Make sure it is installing the app to the Device.
Meaning if you Remove the phone, the App is still able to be ran just like a normal downloaded App form the Market place.
if you want more in depth information, i would suggest Reading the WP7 Everything Programming ebook lol
its filled with good information, and Definitely Helped me along my road to Love DEV for WP7.
As gamernb says, if you disconnect the USB from a properly tethered Windows Phone (i.e. connected to Zune, or using the WPConnect utility), the phone's network connection will be reset and your app's connections will be terminated. The phone will then start trying to connect using WiFi or cellular data (if they are on), but this can take quite a while.
You will have to handle this network disconnection in your app - I've found that pulling the USB cable in this way is a good ad-hoc test for WP7 apps: do an action which you know will use the network connection. Then watch if the app crashes, or handles this gracefully.
Actually you aren't guaranteed to always use the PC data connection: if you make sure that the computer has no data connection (i.e. pull the Ethernet cable, turn off WiFi etc ), the WP7 app can then use cellular data or WiFi on the phone instead.
Alas-
you could set perimeters in your application to Check what the connection type is, then Make changes accordingly.
You May have a slight freeze, but that's better then a crash....mainly when the phone switches from PC to WWAN, their would be a slight Pause.
use the Reachability Class and NSLog to Figure out whats going on exactly.
I really hope that helps!

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