I have an issue where WiFi is not available on an Android device. We want to stream image data from the device using a websocket server (written using WebSocket++) through to the PC. However, I'm not sure if this is possible without operational WiFi. So, the position we are in is that we may only have the USB link available.
Someone today suggested we might be able to get Websockets working using adb port forwarding (see https://developer.android.com/studio/command-line/adb#forwardports), but I'm not sure if that's correct. Could this work, and what would that solution look like?
Are there any other reasonable options. I'm not certain if tethering is available on the device and if that could be another solution?
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I am building a project utilizing Wifi on the ESP32 module. Using RTOS, I am running a web server on 1 core and a web client on another core. This works very well and I can access the web server remotely via my browser and the WiFi provided IP address. The Web client reads some sensors and sends the data via WiFi to my database. All good and everything works as desired.
Now I need to do the next step and move beyond the reach of the WiFi and reproduce the same result via 3/4G cellular. I looked at the "easy" solution to use an industrial 3/4G WiFi router and simply keep what I have. Cost of these "industrial" type routers are on the high side, where as 3/4G module which also include a GPS chip are around half or less. Problem is that I cannot get my head around how I will "replace" my current WiFi functionality with one of these modules. The modules seems to expect you to connect via serial (rs232) and using modem AT commands establish a connection to the internet. Question is, after connecting to the internet, how do you continue to have "network functionality" same as with the built-in WiFi? Is there some library that will do ethernet over the serial port? Can I still have the WiFi and the "serial ethernet" running at the same time or switch between the two?
Thanks!
When I click google cast icon in my chrome browser, it will try to discover whether there is an available chromecast around my pc.
If yes, then it will recognize it (assume that chromecast has already been set and connect to the same router which my pc is connected to).
My first confusion is, during this course, does my pc ever connect to chromecast's own wifi signal? Or they ONLY talk via my router?
My second confusion comes from a test:
I set 2 routers: router_A on top;router_B connects to LAN port of router_A;
My pc also connects to router_A;
chromecast dongle connects to router_B;
multicast/upnp of router B is enabled, firewall on router_B is disabled.
My pc cannot find chromecast in this situation. I'm confused and I think it should work since router_B obtains ip/gateway from router_A.
The third confusion is when I swapped my pc and chromcast, to let my pc connect to router_B, and chromecast connect to router_A, my pc found the chormcast......
After Chormecast is set up with a wifi network, it is discovered through mDNS. For (2) and (3), since discovery is done through multicast/mDNS, you need to read on that topic and look at the configuration settings of your routers to see how you can set things up to get what you want.
I am trying to connect two windows phone emulators without router to form p2p network, is there any solution to connect them with access point without router and internet. and can be a possibility of using IP address of emulator.
answer plz
To the best of my knowledge no it is not possible in Mango - but is in WP8. You could however use a wireless network to perform create a UDP multicast socket and and then "connect" to one another that way.
Have a look at http://blogs.msdn.com/b/davrous/archive/2010/03/29/windows-phone-7-platformer-starter-kit-for-xna-studio-4-0.aspx it's got some pretty good pointers.
My application communicates with several GSM electric controllers, that means that I have to send anywhere between one to twenty messages every few hours. right now I'm working with HUAWEI Mobile Connect - 3G. it is a USB device that uses a comm port for the pc communication and I'm using GSMComm to send messages and read/delete messages from the device.
Every two seconds I'm checking the device's storage, and if there is any message, I will then read it and store it locally and then clear the device's storage. I'm not sure if I'm working correctly, but it seems to me as if it is a very unreliable device:
Every time I boot my machine, I must remove the device from the USB or my machine will get stuck at the BIOS start up screen (or whatever the name is).
Very frequently the comm port can become unavailable for some reason. I have to close and re open the port, and at times that may not even help.
In the production machine of my client, when he uses one of his software's that utilize the first comm port, he will get a warning message from the software about problems in the port if the device is plugged in (the device port is around 28 or something).
If you've been using a device which you consider reliable, or have been working with the same device as I work with, or you just think that I'm doing it wrong, I'd like to get an advice from you.
Thanks.
This sounds like an issue with your modem. Have you tried any other models? Consumer USB models tend to be unreliable. The preferred method, though slightly more expensive, is using a commercial grade modem in situations where you need the reliability.
Some modems to look at:
Wavecom Fastrack
Sierra Wireless Airlink
These use a serial port or ethernet to communicate with the host which is far more reliable. Serial ports may not be available in your particular situation but even a USB to RS232 adapter will be more reliable.
One further option is to use a smartphone, there are several applications that you can act as a gateway through HTTP.
SMS Gateway for Android:
https://market.android.com/details?id=eu.apksoft.android.smsgateway&hl=en
i have not used this method, but it seems like some people are having luck with it. it may not be any more reliable then your USB modem though.
Hope that answers your question.
I have used WaveCom's modem for sending messages in bulks and found it to be reliable. One difference though, in my implementation was i used Kannel as an SMSC, so my queues were automatically handled by Kannel. But sending multiple requests like 40+ per minute didnt pose any problems for me.
Hope this helps.
So I have a bluetooth device, this device uses SPP to transfer data between the PC and itself. It connects fine through Windows as a bluetooth device. I can find it, enter the paring code and assign it to a COM port. Now I want to be able to send data through the com port using Windows API but it is refusing to do so.
I suspect that I need to setup the COMMCONFIG Structure correctly (see below)
http://msdn.microsoft.com/en-us/library/aa363188(VS.85).aspx
Unfortunately I have no idea what is the proper setting. I know SPP is supposed to emulate the RS-232 communication... so maybe I have to study up on that to figure out the right setting? Or is there some automatic way to set the COMMCONFIG structure.
I seriously doubt it. If it would be used then you'll have no chance at guessing at the custom provider data without docs from the driver author. Pay attention to the handshake signals, serial port devices routinely ignore anything sent to them when the DTR signal is turned off. And not send anything back with DTR off. A driver would emulate that. Use EscapeCommFunction() to turn them on. Also try a serial comm program like HyperTerminal or Putty to test this so you can isolate the source of the problem.
Why not use the Bluetooth sockets API? No need for troublesome (virtual) COM ports then.
If you're using managed code then see my library 32feet.NET
If using native code, use SOCKADDR_BTH with Winsock connect etc, see e.g. Bluetooth and connect (Windows) Then you can use the standard Winsock send/recv API
Ok, I found that you can use the
GetCommConfig and GetCommState functions to figure out the settings.