I am facing an obscure behaviour of device naming when trying to use multiple USB midi devices of the same type of hardware. As this might be hardware/system/driver related, here is my general setup:
host: Windows 8.1 x64 (tested on multiple machines)
usb devices: 2x Livid Brain V2 (a general purpose usb-midi interface)
The two devices (same hardware, let's call them device X and Y) are flashed with two different firmware flavours so that they appear with different names in the midi enumeration. If I only connect device X it shows itself as "Brain2" / if I only connect device Y it's "Brain2B". Those are the names I get from the MIDIINCAPS / MIDIOUTCAPS (winmm.dll). So far so good.
The problem arises as soon I connect both devices at the same time, than both get the same name (of the latter connected) - so the enumeration changes:
first X, then Y => both get the name "Brain2B"
first Y, then X => both get the name "Brain2"
However, I can access and use the devices but I am not able to distinguish between them anymore (which is basically the same starting position as having the identical firmware on both devices).
I'd be happy if anyone could point me in the right direction. Has anyone encountered anything similiar? Could this be a system related issue? (Or is it a bad driver, maybe?) Thanks in advance!
EDIT:
I had a closer look at the usb properties with a tool callled USB Device Tree Viewer (similar to USBView) and it turned out the identifiers are correct there. So, how does winmm.dll get the midi enumeration - could it be a bug in there? (unlikely)
Moritz
(btw: here is the related topic/post in the manufacturer's forum: link)
Related
I realized that Android M requires at least one of ACCESS_COARSE_LOCATION and ACCESS_FINE_LOCATION permissions to scan Wifi.
I don't think it's a technical issue but that there is a sort of philosophical reason (e.g., privacy) for such a weird policy.
But I couldn't find the exact reason for that and I would appreciate if someone give the answer.
The list of available Wifi networks for a device can be indeed used to locate the device.
To locate the device on needs the list of of the wifi networks the device can see and a huge database with known wifi networks and the position of the access points. With this information one can triangulate the position of the phone.
Multiple of these huge databases exist. Apple, Google, etc. have each one and there are also public ones: http://www.openwlanmap.org/
Read more about it here: https://en.wikipedia.org/wiki/Wi-Fi_positioning_system
I have 2 Windows Phone 8.1 devices connected by usb cable to my computer. I can use isetool.exe successfully with each phone individually when it is the only one connected. I know I need to use deviceindex:n but EnumerateDevices only returns one device (index 0) when both are connected.
I cannot find any specific examples online nor in the documentation that specify that 2 devices physically connected to the computer will be returned, the same line "Lists the valid device targets and the device index for each device" from Microsoft documentation (https://msdn.microsoft.com/en-us/library/windows/apps/hh286408%28v=vs.105%29.aspx?f=255&MSPPError=-2147217396#BKMK_Syntax) but that could include one device and multiple emulators.
I do not have any emulators set up to confirm if EnumerateDevices only helps in the case of multiple emulators and has a max of 1 device.
Can anyone confirm one way or the other, or shed any insight why i only get one device returned?
Only one physical device at a time is supported; the others would all be emulators.
This is a post for web gl developers.
Are you having nv4_disp.dll blue screen errors since you are developing web gl apps?
I have 1 or 2 every week in the last month. And I think I'm doing almost the same.
(That is , there is not any big difference into my app)
I'm using three & chrome and I promise I have this error playing with little 3D worlds (a simple plane and some lines, believe me). I have opened chrome + devtools.
Some times I have the error while I'm listening music at spotify.
I know this information can be irrelevant but maybe somebody has similar problems than me .
Any idea? Thanks.
Blue screen errors are indication of faulty hardware or faulty graphics drivers. Chrome itself cannot be the root cause of the problem, as Chrome cannot write into kernel space where the problem occurs.
I suggest you change your hardware if you want to get rid of the problem.
You may or may not want to report to this Nvidia, but most likely they don't care about individual reports, especially if the hardware is no longer being sold.
We have a dashboard system (Dashing) that we can view through a browser (Chrome). We have two TVs up displaying this dashboard now. Each TV has a $350 PC connected to it. I am wondering if we could use a Chromecast plugged into each TV and have only one PC "displaying" the dashboard. This is relevant because 1) we are looking at adding monitors after we expand our office and 2) the PCs tend to be a pain in the ..., with things like updates pushed from IT, password chances, etc. One PC would definitely be better. Bonus points if I can get rid of all the PCs and just use Chromecast pointed at a URL.
Thanks,
Although not supported officially, I was successfully able to cast my entire screen to two devices by using both the Google cast and the Google cast (Beta) extensions simultaneously. I could only get it to work using one extension in an incognito window and the other in a normal window.
You can cast to multiple Cast devices if you create an additional "people" in Chrome settings for each of your Cast devices, then open a new window(not tab) for each "people".
Each "people"/user can attach to a different Cast device. It helps to match the user name to the device or location to keep it all straight.
Ex: Cast a movie from NAS to 3 TVs.
Use VLC to stream movie.
Open 3 Chrome/chromium windows(not tabs), changing each window to a unique user/person.
Start streaming.
Point each window at stream, play and cast to a different device.
Performance will depend on ability of PC and router/wifi. We use the Ethernet power supply for Chromecast to reduce load on wifi AP. (We had Cat5 Ethernet already installed)
Since all browser windows are pointed at same stream, the sync is pretty good. Although we usually stream to living room, patio, and game room which a difference hard to detect.
Hope this helps someone.
Currently, you can only be connected to a single device at a time, hence can only mirror to one Cast device. You mentioned you are mirroring your browser. Is the content that you are mirroring a simple page, a video, ...? You may be able to come up with a simple app that would eliminate the need for having PC's completely. Tell us more about the content you are mirroring (hopefully it is not flash :-) )
The Chrome browser extension can only cast to one device. A workaround is to install the Chrome browser extension Beta version alongside the non-beta version, and you'll have a second browser extension that can cast to a second device.
My colleague suggests that if you install Chrome Canary, the Beta version of Chrome, you can run two Chromes, with two extensions each, and support four devices.
Hopefully, this limitation will be removed, and the browser extension will support multiple devices.
Our use case is driving information kiosk displays from a single computer. Chromecast is nice in that the display's physical security does not expose the PC driving the display.
When I use http://html5demos.com/geo to locate myself, it shows wrong location(wrong city) in FF and chrome. Any reason why this is happening
I had the same problem using Chrome on Windows, but I got it to work, at least some of the time.
I was also using the example http://html5demos.com/geo
The location was not just inaccurate, it was also in the wrong city.
I tried the same example on my iPad (Safari) and there the location was correct. My iPad is using the same WiFi network as my PC, so I then knew it was not a problem with my ISP returning the wrong location, it was to do with the browser on my PC.
I got it to show the correct location in Chrome by going into the Chrome settings and clearing the cache and cookies.
It wasn't sufficient to just select in Chrome "Tools/Clear Browsing Data/Cookies & Cache",
it was only after in Chrome I selected "Settings/Privacy/Content Settings/All Cookies and Site Data" and deleting all cookies, did the example show the correct location.
Update 1: I tried the same geolocation example the next day, and to my annoyance it was again showing the wrong city. I tried to get it to work by clearing the Chrome settings as described above and this time this solution didn't work. However, when I used the application CCleaner and selected Cleaner/Applications and cleared all of the Chrome data (internet cache, internet history, cookies and session) the geo example showed the correct location. I'm using the latest version of Chrome. Hopefully in future versions it will work more consistently.
Update 2: I tried the procedure above at a later date and couldn't get it to produce the correct location at all. It could be that the geolocation is now returning the location of my internet service provider, rather than my location, using my IP and Google Location Services. Of course this location is fairly useless. The reason why my iPad is returning the correct location is probably because it contains an inbuilt GPS. The iPad 3G / 4G have a GPS chip built in to the GSM receiver chip, whereas WiFi only models have no GPS. When 'location services' are switched off in the iPad settings, location via both GPS and IP are switched off. It would be useful just to be able to switch off the GPS on my iPad and just use IP location, but I'm not sure if that is possible.
Update 3. As I mentioned, I'm using a WiFi stick in my PC. I have noticed that when I look at the available WiFi networks (with View Available Wireless Networks) and mine is the only network, the geolocation example returns a location in a different city, but if any of my neighbours have a WiFi network in range of my PC, the geolocation example returns my exact location, to within a few metres. i.e. the geolocation in the browser is clever enough to use this extra information to locate me.
(I think the other answers to this question completely on the wrong track. The questioner states that the location was being shown in the wrong city, so the question is not to do with the location accuracy)
Different devices have different degrees of accuracy and it is important that your application be aware of the difference. A cell phone that has a GPS unit inside of it that is switched on is usually accurate within three meters. A cell phone without a GPS unit, with the GPS unit switched off to maximize battery, or at a location where the GPS can’t contact the GPS satellites will have to use cell tower triangulation to estimate the users location and is typically accurate within 3000 meters which is accurate enough to know what neighborhood the user is in but completely useless to tell them what building they are looking at.
If the user is accessing your site from a computer connected to a land-based broadband connection it can usually pinpoint the precise address by consulting a provider database and pinpointing the exact address from the DSL or cable provider.
To get the accuracy of the location information, you can query the accuracy property on the coords object. The accuracy property isn’t exact by any means but it will give your application a good sense as to whether or not you have a nearly precise position or a neighborhood.
According to the Firefox geolocation FAQ, Firefox uses Google for location services. It sends Google the following information:
Your IP address
Information about nearby Wi-Fi access points
A random Google-assigned identifier (changed weekly)
I assume it will also use GPS data if your computer has a receiver installed, but the FAQ doesn't mention that. Maybe because there's no need to use Google's sever if you have GPS data available.
I assume that Chrome, as a Google product, is using the same geolocation database.
As for why you're getting incorrect answers, that would reside in Google's database. There are most definitely errors in there. For instance, my office computer shows up in Mexico city even though my IP address and the IP address of my employer's proxy server are both in Plano, Texas, and all other IP-to-location databases have this correct (taken from the registered whois data for the address.)
Here are two Google pages that they claim will help, although they haven't done a thing for me yet:
https://support.google.com/websearch/answer/873
https://support.google.com/websearch/contact/ip
The latter (contact/ip) is a form for reporting Google location problems that manifest as Google redirecting you to the wrong country's home page. They say it may take over a month to correct the database. I've been waiting nearly two months with no luck.
There are Firefox add-ons that can be used to force your browser to report a specific location. They're meant for debugging location-aware web services, but they could also be used in a case like this, where the normal method isn't working.
I think if you could user the the method watchPosition() instead of getCurrentPosition() the coordinates will be updated too much which will produce a better result
note : it's better to use another browser other than chrome it doesn't support the watchPosition() method good enough
I figured it out. Every mobile phone has its location mode default to High Accuracy. High Accuracy uses GPS, Wi-Fi, Bluetooth, or mobile Networks to determine location.
This might be a challenge as there are many variables to getting a device's location.
The solution will be to change the location mode from High Accuracy, to Device only or GPS only.
Device only or GPS only is supposed to use just GPS and device sensors to determine location. I have tried it, it works like a charm.
Use link below to change Location mode
https://www.verizon.com/support/knowledge-base-106080/
I depends on which method is used to get your location. If it uses IP then you could show up pretty much anywhere. If it uses Wifi then it might be just be biased data.