Just curious:
Why are acknowledgments used in WLAN but not in IEEE 802.3?
can anyone help please? Thanks
because wireless(WLAN) network is not as reliable as wired(IEEE 802.3) network
Related
Do someone know how to write a simple code that enable the PTP and use it to synchronize the clock between two microcontrollers ? any idea ?
I have no idea to code for nxp microcontroller
I would like to connect an USB webcam to my EV3.
is it possible to do that?
and how can I do it and how can I reach the cam from my code?
I use Labview for programming
and thanks in advance :)
Both leJOS and ev3dev support USB web cams connected to the EV3 brick, however, neither work with LabView.
To get this working on the official LEGO firmware, you need to compile proper kernel modules, sideload them on the EV3 and as suggested in the comments, sideload another program that converts the image data into something that can communicate with labview remotely.
use bellow vi to convert image to 2d array use array tool to cut appropriate part
and do not forget for average use this equation otherwise the answer will be wrong
ave=r/3 + b/3 +g/3 not r+b+g/3
vi
I was thinking if it is possible to detect other RF signals in the environment using my laptop? I don't know if there are any programs which does this, but I think there might be a solution for this, perhaps by working on wifi drivers.
I'd be thankful if anybody helps me out. Thanks in advance.
Yes there are programs that do this, i.e. Metageek. I have also seen people build their own home-brew spectrum analyzer if you are so inclined.
I have seen several projects now which derive novel spatial information from radio data collected from a typical wireless router:
http://wisee.cs.washington.edu/
http://www.extremetech.com/extreme/133936-using-wifi-to-see-through-walls
The idea of using a wireless router as a sort of passive radar is fantastic.
I am very interested in experimenting with data collected from a wireless router myself, but there is little information on how to go about actually interfacing with a wireless router and getting a raw stream of information collected by the device. Similar questions have been asked on here before, but I am yet to see a satisfactory answer.
I don't have the rep points necessary to link to the other questions but see:
'Capture Raw Signal from WiFi card as You Would a Sound Card'
'raw wifi “signal data” access'
I am looking for a solution that would let me use a low-cost device such as the oh so common WRT54G wireless router. If your answer involves custom radio hardware, you needn't bother posting.
As far as I know, the only option using a commodity hardware is to use Intel 5300 Wifi card. You can get the complex CSI (amplitude and phase info therein) from the three antenna on it from a sample of subcarriers (OFDM). You can take a look at this site:
http://dhalperi.github.io/linux-80211n-csitool/
If you read the wisee research paper you will find the platform they use for the system, it is USRP N210 from Ettus plus GNU radio software.
So it is not your usual WiFi AP they are using but the SDR solution this question also hints about.
WiFi devices are build to handle physical layer in silicon and the monitor mode is the best thing you can get without going the SDR path. You can get quite a lot of information from it - the radiotap header contains for example received signal strength and receiving antenna information. But if you really want to explore physical layer of WiFi then commodity hardware is not going to cut it.
I bought transparent RF modules DRF1212D10 and UART-USB convertor board from Dorji applied technologies. However the USB convertor board uses CP2102 chips and the RF module needs the RTS pin of CP2102 to be controlled in order to work in normal mode. I have tried several serial port monitor software but there is no RTS control option in the software interface.
I really appreciate if somebody knows which software has such option. Thanks in advance!
I use PuTTY. There you can set Connection type to Serial and in Category view: Connection->Serial->Flow control to RTS/CTS.