I'm trying to make two Kinects getting along under the same application. I've tried to start all the connected Kinects (by calling the Start() method), but only one has the "isRunning" flag set on true. Does anyone know why is only one sensor running?
LE: I connected the two kinects on different USB controllers ... same problem. I've enabled all exceptions, and I get this, when the start method is called for the second kinect:
This API has returned an exception from an HRESULT: 0x830100AA
The stack trace:
at Microsoft.Kinect.KinectExceptionHelper.CheckHr(Int32 hr)
at Microsoft.Kinect.NuiSensor.NuiInitialize(UInt32 dwFlags)
at Microsoft.Kinect.KinectSensor.Initialize(SensorOptions options)
at Microsoft.Kinect.KinectSensor.Start()
Regards!
Kinect sensor requires a lot of USB bandwidth so each Kinect should be connected to a separate USB controller. Try connecting both of them to different USB host controllers. You can also verify the status under "Microsoft.Kinect" node in Device manager.
I disabled the skeletal tracking and now both kinect sensors are running. But now the question that arises: Why it's not possible to enable also the skeletal tracking?
Related
I am writing a driverkit extension whose goal is to block some categories of USB devices, such as flash drives. The driver should block (match to) any device of the relevant device classes, except those, which are whitelisted (based on their vendor and product ID). The whitelist can be set dynamically by user of the application.
The question is, how to pass these data to the driver as reading from a file or something like Windows registry is not available in the DriverKit. The tricky part is that the driver requires the whitelist data before the device is matched.
From what I understood, rejection of device is possible by returning an error from Start() method and returning from it prematurely. I got an idea to send the data while the driver is running this function, however this is not possible as the communication via IOUserClass is not available until the Start method returns.
Is this somehow doable?
As far as I'm aware, communicating with user space apps from the initial Start() method is not possible from DriverKit extensions. As you say, IOUserClients are the mechanism to use for user space communication, and those aren't available until the service is started and registered. You can have your driver match IOResources/IOUserResources so it is always loaded, but each matched service starts up an independed process of your dext, and I'm not aware of a way to directly communicate between these instances.
If I understand you correctly, you're trying to block other drivers from acquiring the device. I don't think the solution you have in mind will help you with this. If you return success from Start(), your dext will drive the device. If you return failure, no driver is loaded for the device, because matching has already concluded. So other drivers would never get a chance anyway, regardless of whether the device is on your allow-list or deny-list.
It's new in DriverKit 21 (i.e. macOS Monterey), and I've not had a chance to try it yet, but there is an API for reading files, OSMappedFile. I would imagine that the DriverKit sandbox will have something to say about which files a dext can open, but this seems like an avenue worth exploring whether you can open configuration files this way.
Note that none of this will help you during early boot, as your dext will never be considered for matching at that time. And you may not be able to get required entitlements from Apple to build a dext which matches USB device classes rather than specific product/vendor ID patterns. (Apologies for repeating myself, but other users may come across this answer and not be aware of this issue.)
I want to build something with Raspberry Pi Zero and write in Go,
I never tried bluetooth before and my goal is;
Sending a dynamic packet which it will change every second, an iOS app will expand this message and with a button, client will send a message back without a connection.
Is Bluetooth Advertising what I am looking for and do you know any GoLang library for it? Where should I start?
There are quite a lot of parts to your question. If you want to be connection-less then the BLE roles are Broadcaster (beacon) and Observer (scanner). There are a number of "standard" beacon formats out there. They are summarized nicely on this cheat sheet
Of course you can create your own format as these are using either the Service Data or Manufacturing Data in a BLE advertisement.
On Linux (Raspberry Pi) the official Bluetooth stack is BlueZ which documents the API's available at: https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc
If you want to be connection-less then each device is going to have to change it's role regularly. This requires a bit of careful thought on how long each is listening and broadcasting as you don't want them always talking at the same time and listening at the same time.
You might find the following article of interest to get you started with BLE and Go Lang:
https://towardsdatascience.com/spelunking-bluetooth-le-with-go-c2cff65a7aca
My team has been struggling with a pretty strange issue while using the WinRT/C++ APIs for Windows to connect to both a MIDI port and receive BLE notifications through a proprietary service on the same device.
The WinRT/C++ library itself is really nice and provides easy and modern C++ interfaces to access the managed Windows runtime classes.
I've pushed a sample repo to Github where we've replicated the issue with a minimal example.
The repo's readme goes over the problem in detail, but I'll post the relevant bits here for completeness.
The sample program is performing roughly these steps:
Check for available MIDI devices using a DeviceWatcher.
Check for available Bluetooth LE devices using another instance of a DeviceWatcher.
Match discovered MIDI and BluetoothLE devices on their ContainerId property (see DeviceInfo for details). This is the method JUCE employs in the native WinRT code for their library, and works as expected.
Open the MIDI port and attach a handler to the MessageReceived event (see the code).
This causes the system to create a connection to the Bluetooth LE device. The program detects this state change, creates a BluetoothLEDevice, we perform GATT service discovery and attach a handler to the ValueChanged event for the characteristic we're interested in notifications from (see the code).
The program then counts how many MIDI messages are received on each port and how many BLE notifications are received from the corresponding device.
The behaviour we notice is that data from the most recently connected device streams just fine, while the throughput for the others is severly limited. We are at quite a standstill regarding this issue, and are not sure where the problem may lie.
We are at quite a standstill here. I'd be more willing to accept it if all the devices would exhibit this behaviour, but that's not the case. Is there any reason that creating both a MidiInPort and an BluetoothLEDevice from the same peripheral should cause this issue?
A BLE radio can only receive or send at any given time. And therefore only communicate with one device at any given time. It uses a scheduler to allocate radio time for every device when you have many devices. That way a second connection can "interrupt" a connection event from another device, decreasing the throughput for that device. See https://infocenter.nordicsemi.com/topic/sds_s132/SDS/s1xx/multilink_scheduling/central_connection_timing.html
I've recently started playing with esp32. I was searching for various WiFi.mode() options available for esp32 but I couldn't find it anywhere. Can anyone help point out the source for that information?
Thanks
The code for the ESP32 Arduino SDK WiFi class is located at
https://github.com/espressif/arduino-esp32/tree/master/libraries/WiFi/src
WiFi.h doesn't define a method for mode() but it does inherit from WiFiGeneric.h which does have methods for mode() and getMode(). You can find the code for those methods in WiFiGeneric.cpp.
The mode is represented using type wifi_mode_t, which is defined in WiFiType.h. The available options are WIFI_MODE_OFF, WIFI_MODE_STA, WIFI_MODE_AP, and WIFI_MODE_APSTA.
There is some resonable but partial doc on the Espressif pages: Espressif Wifi doc
This doc explains some of the different wifi modes of the esp32 that can be found in WiFiType.h.
WIFI_MODE_NULL : The null mode or the WIFI_MODE_OFF which is the OFF mode
WIFI_MODE_STA : The Station mode, which is the standard client mode
WIFI_MODE_AP : The Access Point mode where clients can connect to the ESP32
WIFI_MODE_APSTA : The hybrid mode where the ESP connect to an AP as a client and recieve connections from client as an AP.
WIFI_MODE_MAX : The MAX mode has no explaination on what it is supposed to do. But it dose not seems to be implemented anyway.
The WiFi mode types come from an enumerated list. WIFI_MODE_MAX is the last entry in the list (and I guess that's why it's MAX). An odd convention as WIFI_MODE_UNKNOWN or similar would be more intuitive.
I have been using Windows APIs for NFC communication. I am successful in getting and sending NFC messages from Windows PC, using a local console app. However, I want the communication to be done using a Windows service. Here is what I have:
A C# plugin (DLL), which makes the API calls.
C++/CLI Wrapper that allows unmanaged C++ code, to use the above plugin.
A C++ plugin, that the service will load (this is a requirement, it has to be a plugin)
If I load the C++ plugin into a local console app, and run, it can catch all NFC events (NFC device arrives in proximity, departs from proximity, can read and write to it). But, when I use the same plugin with a service, it is not able to catch those events. I can clearly hear the ping sound that comes when an NFC device comes close to Windows PC, however, none of the event handlers are called (For device arrival, device departure, read or write).
I also tried impersonation thinking that perhaps the context of who calls the method might result in blocking of the events. I could impersonate local user on the service, but the results were the same, no events could be identified.
Is there a reason why I cannot see any NFC events from a service, where as a local console app can get all of them? Again, I am able to hear the ping sound signifying that NFC device is close to Windows PC, but there is no handler getting called for it, suggesting there is blockage of something. Any ideas of what is going on?
Appreciate your time guys!