I am trying to send some data (in the form of raw bytes ) from my device to host(connected through USB). What can be the different ways to do it ??
One idea is to write the raw bytes in one of the ring buffers (in /dev/log/) and let the logcat read it. But logcat expects the formatted strings in ring buffers, Is there a way to modify the behavior of logcat ??
or is there a way to create a tcp connection between host and device to transfer the data???
Any other suggestions ??
Thanks.
adb forward is your friend. You can do port forwarding and then run TCP servers on either the host or the device.
EDIT: see http://developer.android.com/guide/developing/tools/adb.html#forwardports for more detail.
Related
I am logging GPS data on a Raspberry Pi (Raspbian OS) by forwarding text from an Android phone connected by USB. The app ShareGPS correctly dumps several lines of text every second to port 50000. On the Pi I run adb to forward the port to the Pi.
From there I redirect the socket using a pseudo path to a file descriptor and then redirect the descriptor to a text file.
adb forward tcp:50000 tcp:50000
exec 3<>/dev/tcp/localhost/50000
cat &3 >> dump-file.txt
To me this seems a very convoluted route. Is there a more efficient way record from a port on the phone to a text file on the Pi?
Phone setup and adb reference http://ubuntuforums.org/showthread.php?t=2145434
Socket redirection http://hacktux.com/bash/socket
If you don't need back-and-forth communications, you don't have to open a separate FD:
cat < /dev/tcp/localhost/50000 > dump-file.txt
One way or another, there will need to be a process that listens to the port and writes to the file as there is no built-in O/S function to do so.
So, really, there isn't going to be a more efficient way to run that. You might be able to save some startup cost by turning the script into a program, but I wouldn't bother - the savings will be tiny.
i would like if my question is possible or not.
Well every channel has a specefic frequency 1 à 13(2,4GHz), 36 to 64(5GHz) and 100 to 165(5GHz).
for example :
channel number 1 : 2412GHz ;channel number 2 : 2417GHz.
Well when we enter to the router interface from the localhost address ,we can easely choose a channel.
What i would like to do is to change the channel programmatically (from my android app ) .
I have an idea ,but i don't know if it's feaseble or not ,is to simulate the router web interface and do the same work that it doeas with android.
if someone has an idea please help me
PS: 'm the router adminsrator
Thank you
I think that is possible you connect to your router by SSH, and then, you change the configuration, and restart wireless, but, then, you will lost connection when channel changes.
However, I dont know if your router allow this operation with SSH
I have another idea:
With wireshark, see the HTTP packet sent between your PC and your router, when you does Login, and when you save configuration. If you understand them, maybe you make a new packet in your phone.
(sorry my English)
You can try to configure the router with SSH.
I am currently developing an android app and i want to send data message with audio file attached to it. One of the arguments of the sendDataMessage() methods is "destination port".
I know its the port i want to send the message via, but I am not sure what to put there, is there a default port for sending data messages? I have looked for it but every example I have seen uses different port. However, whichever port I use, I get Null PDU exception.
I am using HTC for running and testing the app btw.
Default is 8091. Most devices don't support port filtering very well, though:
SmsManager.sendDataMessage(..., onSpecificPort , ...,.. ) Is not Filtering SMS On Port Basis
Your null PDU is probably not because of a port selection problem, though.
I am using TCPDUMP-arm because I'd like to capture TCP packets arriving on my tablet. The problem is that I want to get rid of the results about the outgoing packets.
When I execute:
./tcpdump-arm tcp -qt -l > /sdcard/res.txt
I get results like:
IP 172.17.***.***.49890 > 74.125.***.***.5228: tcp 139
IP 172.17.***.***.56869 > 173.194.***.***.80: tcp 0
IP 173.194.***.***.80 > 172.17.***.***.56869: tcp 0
Where the IP starting with 172.17. is mine.
So, is there a way to adjust TCPDUMP to show me only the last result (the one where my IP is destination)
Not sure about tcpdump-arm (never used it), but assuming that the pcap-filter expression is the same as tcpdump's (which is quite likely, I'd think), then to see tcp traffic and leave out packets where your IP address is the source, your expression should be:
tcp and src host not 172.17.x.x
Can't try it out now to be 100% sure, but I'll leave that to you.
I've managed to deal with the problem :)
Also , I created one ToggleButton in my app , in order to Start/Stop TCPDUMP. Now I want to be able to read the text file which is generated, while the program is still executing , and make decisions based on the data from the file.
The problem is that I want to read only the latest results , and so far I can just read the whole file from begging to the end. My other option is somehow to read the output from TCPDUMP directly/live in my app , without making a text file , but I have no idea how to achieve that.
I am looking forward for your replies.
I need to get my app to play a video file located on my network. I know the url of the file is:
http://something.local/abc.mp4
Now, when I manually substitute "something.local" with its true ip address, the MediaPlayer has no problem playing it. Nonetheless, when I have the above address, the MediaPlayer errors out with error (1, -1007).
So I'm assuming this is because Android doesn't understand "something.local" as being correct.
My question is: How can I "translate" something.local into an ip myself, so that I can then pass it into MediaPlayer?
A small caveat: I believe that MediaPlayer does not work with IPv6 addresses, so please keep that in mind...
Just a side note, in case it makes my situation clearer: When I run ping something.local -4 in the Windows command prompt, it returns:
Pinging something.local [192.168.1.126] with 32 bytes of data:
Reply from 192.168.1.126: bytes=32 time=145ms TTL=64
Reply from 192.168.1.126: bytes=32 time=112ms TTL=64
Reply from 192.168.1.126: bytes=32 time=32ms TTL=64
Reply from 192.168.1.126: bytes=32 time=169ms TTL=64
That translation where windows went from something.local -> 192.168.1.126 is what I want to do in my Android app.
Firstly, you need read document about Bonjour (iOS term) or Zero Config (Linux term).
To understand what's something.local:
http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/NetServices/Articles/about.html#//apple_ref/doc/uid/TP40002458-SW1
For example, if a user types steve.local. into a Web browser, this
tells the system to multicast the request for steve on the local
network instead of sending it to the conventional DNS server. If a
Bonjour-enabled computer named steve is on the local network, the
user’s browser is sent the correct IP address for it. This allows
users to access local hosts and services without a conventional DNS
server.
For how to resolve it:
http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/NetServices/Articles/NetServicesArchitecture.html#//apple_ref/doc/uid/20001074-SW1
For java library, previous answers provided good enough example.
You should try this snippet with jmDNS library api.. may need some changes.
JmDNS jmdns = JmDNS.create();
DNSEntry addressEntry = jmdns.getCache().getDNSEntry(name, DNSRecordType.TYPE_A, DNSRecordClass.CLASS_ANY);
if (addressEntry instanceof DNSRecord) {
ServiceInfo cachedAddressInfo = ((DNSRecord) addressEntry).getServiceInfo(true);
if (cachedAddressInfo != null) {
for (Inet4Address address : cachedAddressInfo.getInet4Addresses()) {
// use the `address`
}
}
You have access to java,net APIS on android and can use them to resolve adresses.
http://docs.oracle.com/javase/1.4.2/docs/api/java/net/InetAddress.html
However, success will depend on network proper configuration. Your device receives DNS server setup via DHCP - so you are at mercy of network provider