Headache saver - disable Microsoft serial mouse detection...

[bagmouse7]

I couple of days ago I did an update on the RX-II and I noticed that the configuration software was never able to reestablish communication with the hardware (updates had always worked correctly before).
I rebooted my PC (Windows 10) to see if that would clear up the issue, but it did not.
When I checked the Windows device manager I noticed that the virtual serial port was not listed, but what was listed was a "Microsoft Serial Mouse".
I have actually seen this issue before on Windows 7 with some other hardware that communicated using a serial port.
I think sometimes Windows misinterprets some random communication on the serial port as a serial mouse and adds it to the device manager.

Fixing this was easy, fire up regedit and

1. Navigate to the registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\sermouse
2. In the right pane of the Registry Editor, select Start and change it’s value to 4 to disable serial mouse detection at boot time.
3. Reboot

Disable Serial Mouse Detection in Windows 10 – Neeper

www.neeper.ca

This tip might save someone else some aggravation...

 

[btt]

I'm not sure why this would happen. The P25RX/P25RX-II map in with specific names into the USB device tree. The software searches for these strings to find the correct model / device. The software would never attempt to connect to a serial mouse. It may be that the act of rebooting solved some other issue? If this is an actual issue, then I think it would most likely be a bug in Windows and not the P25RX / firmware / software.

 

[N2YQT]

Ahh yes. I had a ToughBook with a built in GPS that thought it was a serial mouse at first. It looked like it was possessed until I disabled it!

 

[btt]

Ahh yes. I had a ToughBook with a built in GPS that thought it was a serial mouse at first. It looked like it was possessed until I disabled it!

What version of Windows was this?

 

[K9DAK]

It's not a BUG... it's an un-documented feature...

 

[btt]

It's not a BUG... it's an un-documented feature...

I shouldn't have responded. lol. MS has always been a thorn in my side. I realize that I have to support it. I always have. I haven't seen too many complaints over the decades. Even though I am a hardware engineer for the most part, a significant portion of my career has been firmware / software. Java was a big break. For the most part it solved the issue between platforms. Still, there are a lot of issues with Microsoft that just don't make sense. lol. Other platforms don't have these issues. I still say this issue is not due to the P25RX and related software. Also, I really doubt the issue is Windows 10. There is no way that the OS could confuse this device with a "serial mouse". Not in 2010 and >. Right?

 

[bagmouse7]

This error happened on a Windows 10 Home - build 19044.1526, (latest W10 auto-update version as of 2-12-2022).

I don't think this issue should be blamed on the P25RX-II. I have have had this same issue happen with an Optocom radio hooked up to a physical serial port on this same W10 box. And, its not just a W10 issue, I had the same issue happen with the Optocom on a previous W7 box.

The excellent technical discussion in the link below details how easy it is for Windows on mistakenly think a serial mouse is connect.
I guess in their defense it is important to detect a mouse as quickly as possible, but the reality is that serial mice are rarely (never?) seen these days...

https://stackoverflow.com/questions/9226082/device-misdetected-as-serial-mouse

Here is a sample:
----
It turns out that mouse detection in Windows is normally handled by the serenum.sys filter driver. This driver implements support for legacy serial mice along with serial plug-and-play. Microsoft has even provided the sourcecode as a WDK sample.

During detection the ports switches to 1200-7-N-1 mode while asserting DTR+RTS to which a response is expected within 200 ms, with a couple of retries in case of failure. Unfortunately for a legacy mouse a single M or B character suffices as identification.

In our case the protocol was reworked to avoid these characters and now appears not to be misidentified anymore.

However we were using a virtual USB serial port and for a traditional serial port this approach may be somewhat difficult as anything sent at a different baud rate is liable to look like line noise. In this case I suppose the easiest workaround is probably, as has already been suggested, to avoid making any unsolicited transmissions.

Alternatively with the serial control signals actually hooked up, or intercepted by a USB CDC device, processing the DTR or RTS signals and holding off on output. Actually implementing the plug-and-play protocol would be an even niftier option. Supposedly there are cheap RS232 cables around without a full complement of control signals though so this approach might still fail.

---

In my case I used the P25RX-II for about 2 weeks and did about 5 upgrades with no issue.
After the last update the P25RX-II could never be seen on the serial port of the control software.
Rebooting didn't fix the issue.
Checking the Windows device manager showed that the previous virtual COM port was missing and a "Microsoft serial mouse" had been detected.

I disable the autodetection as detailed in the first post, rebooted and everything was fixed.
Thanks Windows!