I am workin on a small internet browser in Xcode for OS X using the WebKit framework and I was wondering if it was possible to get a WKWebView's live connection speeds (Upload and Download) to the website and display them in Level Indicators (and write values next to them in textfields). (or any alternatives if not possible with WebKit) Thanks :D
To determine the actual speed, you need to measure the time it takes to upload or download a buffer of known length. If you just need to know if they're connected via WiFi or some other (presumably slower) method, there are ways to determine the type of connection you have. Here's a random example I found for doing this: How to check for an active Internet connection on iOS or macOS?
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I was able to make a working HID USB stack on my "StartUSB for PIC" board for the 18F2550 microcontroller. I based it on one of the MLA libraries, which was made for the 18F45K50 (MLA 2018_11_26, hid_custom, picdem_fs_usb_k50.x), but I converted it to work with the 18F2550 (there might have been easier ways, but only learned to work with PIC about 1 month ago). On the host side, I'm using LibUsbDotNet (also here, there might be easier ways - the documentation on this library really sucks) on a Windows 10 machine.
I'm using the HID class, full speed, and all seems to work. Although, I get some random errors on the host PC (see below), but doing one close/re-open cycle on the host side when getting the error is kind of solving it. Dirty, but it works. So I kind of ignore this now.
Win32Error:Win32Error:GetOverlappedResult Ep 0x01
995:The I/O operation has been aborted because of either a thread exit or an application request.
I'm not an expert on USB (yet). But all examples I'm seeing are based on 1) you send first a command to the device and 2) then you retrieve the answer from the device. I did some performance tests, and see that this indeed shows that I can do about 500 cycles/second. I think that is correct, because each cycle, sending command and retrieving answer, each takes 1 msec.
But do I really need to send a command? Can't I just keep reading endlessly, and when the device has somthing to say, it does send the data in an IN transaction, and when not it ignores which creates a timeout on the host side. That would mean that I can poll at 1000 cycles/second? Unfortunately, I have tried it by changing my implementation on the PIC, but I get very weird results. I think I have issues with suspend mode. That brings me to another question - how can I make the device get out of suspend mode (means that not the host, but the device should be triggering this event). I have searched the MLA library for command such as "wakeup", "resume", ... but couldn't find anything.
So, to summarize, 2 questions:
Conceptual: Can I send data from device to host without being requested for it by a command from the host?
For PIC experts: How can I have a device trigger for a wakeup from suspend mode?
And indeed, the answer is Yes on the first question.
In the meantime, I found another link on the web that contains a Visual Studio C# implementation of a USB library including all the source files.
If you're interested, this is the link
This C# host implementation works as a charm. Without sending a command to the device, I get notified immediately if a button is pressed. Great!
It also proofs that my earlier device implementation based on the original MicroChip MLA, is 100% correct. I stress tested the implementation by sending a "toggle LED command" as fast as I could, and I reach 1000 commands/second. Again great!
I think that LibUsbDotNet isn't that perfect after all. As I wrote above, I get rather unstable communication (Win32Error). But with this implementation, I don't get a single error, even after running for half an hour # 1000 commands/second.
So for me, case closed.
I searched for a long time in Objective-C on how I could retrieve some stats for bytes in/out of macOS network interface and haven't found anything.
I thought about using command line, and find an OS stats on socket (maybe in sysctl) which I could use to make some math, but haven't found.
I tried to grep on nettop, but the way it's done in CLI is impossible to grep.
I just found 2 apps on AppStore which does't exactly this, showing bandwidth used in real time:
https://itunes.apple.com/us/app/network-scanner/id1103147103?l=en&mt=12
https://itunes.apple.com/us/app/network-inspector/id515794671?l=en&mt=12
I tried to use Activity Monitor and sample process to understand the call they do without success.
Any idea on how those two apps retrieve number of bytes in/out of network interface?
I'm working on a large scale music app and I'm having trouble with some nodes not connecting and disconnecting properly.
Is there a method in web audio to see a list of current connections a AudioNode has?
I've tried using Firefox's Developer browser as this shows a view of all current connections but the problem is that it's viewer really can't handle more than about 15 connections.
It would be great if there was something like: osc.connections(); which would return an array of nodes the osc is connected to.
If the Firefox tools doesn't do the trick, then I think the answer is no. I think I saw a Chrome extension which did something similar way back, but I can't find any trace of it.
Your best option is probably to keep track of the connections yourself, unfortunately.
I have been using SimpleWebRTC lib for my project.
How to change dynamic remote video resolution during a call (like google hangout when resizing browser)
hangout browser resizing will change remote video resolution size (.videoWidth .videoHeight)
Is this associated with webrtc plan b?
I would like to know how it is implemented for many peer connection.
Tell the sending end (say via DataChannels) to change resolution to NxM. At the sending end, until the new APIs are available to change a getUserMedia/MediaStream capture size on the fly, you can request a second camera/mic stream and replace the existing streams with them. (Note: this will cause onnegotiationneeded i.e. renegotiation, and the far side would see a new output stream.)
Smoother (but only in Firefox thus far -- in the standardization process) would be to use RTPSender.replaceTrack() to change the video track without touching audio or renegotiating.
Another option that will exist (though doesn't yet in either browser) is to use RTPSender.width/height (or whatever syntax gets agreed) to scale outgoing video before encoding.
Plan B for multistream/BUNDLE (which Chrome implements) was not adopted; Firefox has now (in Fx38 which goes out in a few days) implemented the Unified Plan; expect to see a blog post soon from someone on how to force the two to work together (until Chrome gets to implementing Unified Plan)
I'm trying to create an embedded outdoor display of bus arrival times at my university. I'd like the device to utilize my school's secured WiFi network to show arrival time updates determined from a server script I have running.
I was hoping to get some advice on the high-level operation of this thing -- would it be better for the display board to poll a hosted database via the WiFi network or should I have a script try to communicate with the board directly over 802.11? (Push or Pull?)
I was planning to use a Wifly or WIZnet ethernet board in combination with a wireless access hub. Mostly inspired by this project: http://www.circuitcellar.com/Wiznet/winners/001166.html Would anyone recommend something else over one of the WIZnet boards? I saw SPI/UART options and thought these boards could work with an AVR platform.
And out of curiosity -- if you were to 'cold start' this device (ie, request a bus arrival time by pushing the display's on button) you might expect it to take 10-20 seconds to get assigned an IP and successfully connect to the database, does that sound right?
I'd go pull. In fact, I'd have outdoor display make http or https requests of the server. That way the server could tell it how long to show a given set of data before polling for a new one using standard http page expiration.
I think pull would make it easier to have multiple displays, and to test your server as well. I've also got a gut feeling that this would make your display more secure. Someone would have to hack your server to hijack your display.
There's a very cool looking Arduino-targetted product called the WiShield. Seems super easy to use and he provides some source code. It uses SPI for host communication. If you're not interested in going the Arduino route, I'm sure the source code wouldn't be too hard to port to something like avr-gcc. Check it out, might save you some time and headaches for $55. Worth checking out anyway.