is it possible to use" Freemodbus "as master side ?
i'm going to impelement it on stm32f4xx ARM pocessor
if not ,introduce me alternative protocol that works on RS485 physical layer...
I have looked over the website for FreeModbus and it doesn't appear that it supports master-side implementation. I'm not turning up any hits in a quick search for a Modbus master library for embedded devices. I'm sure someone has one out there, but it may not be free.
As for alternatives, that ends up being primarily opinion based and off-topic for Stack Overflow.
The FreeModbus open source code NOT contain master mode. I rewrite it and add the master. You can tyr it on stm32. https://github.com/armink/FreeModbus_Slave-Master-RTT-STM32
You can try this it also include Modbus Master with GNU GENERAL PUBLIC LICENSE. I am also trying it.
Related
I've asked this question on :https://electronics.stackexchange.com/
with no success, So I'm trying my luck here.
I've designed a board that used a SAM uC (Cortex M0+). I don't want to use the ATmel Stduio, I want to learn how to use eclipse and arm-gcc and OpenOCD ( still can't understand, what this one is for ?). So my question is it possible to do that and if yes, does anyone has hint how can I proceed ?
I've installed the 3 parts,and this is the farthest I could get:
I agree with Notlikethat, what is it that you cant figure out.
1) Yes, I have dozens or hundreds of bare metal microcontroller examples that use the gnu toolchain, no ides, just the command line. No problems there whatsoever.
2) OpenOCD is an open source tool that knows how to speak to the on chip debuggers, in particular ARM ones. And it supports JTAG and SWD which is what your cortex-m0+ will have if exposed (which it most likely is).
3) which SAM microcontroller there are hundreds of different ones over a decade or so, the cortex-m0+ certainly narrows that down from what is actually more like thousands to more like hundreds of different ones. Narrow it down to at least one family. Is it the popular SAMD21? I have personally used one of those, and using openocd and gcc is quite doable without any need for an IDE from anyone. Just add a text editor.
I prefer to use a $10 st discovery or nucleo board as my SWD debugger, remove a couple of the jumpers and you can use that st-link front end for other microcontrollers st or not st.
The chip documentation as well as google will show you how to hook all this up and talk to the chip.
Do you have just a raw chip or do you have it on a board, one you made or one you bought?
Your question is the equivalent of, I have a Ford, and I dont know what size brake pads I need and do I have to have the dealer install them.
Is it a truck is it a car, which one, how many models/variations have they had in the last hundred or so years? Look up the sizes/parts in a manual. And the latter is yes of course you can do it yourself, or have someone else install them, you dont have to go to the dealer.
I've followed Microsoft's directions to disable updates, telemetry and crash reporting, but VS Code is still talking to the web. It looks like there's something going on in editorSimpleWorker.js and editorWorkerServer.js, but those are some pretty big haystacks to start combing.
Does anyone know what VS Code is trying to accomplish by talking to the web? Marketplace? npm? And how to disable it? I can block the outgoing TCP traffic, of course, but besides that?
As of now, two weeks after posting the question, I am pretty confident in making the following statement:
There is no documented configuration option or combination of options that will turn off all web traffic conducted by Visual Studio Code.
At least some of the traffic that I've observed is related to the extensions gallery.
Ultimately, VS Code was built to be online. It is intended to talk to the web. If you are trying to use it in an environment in which such connectedness is discouraged, you will have difficulties of some type or other. Instead, find a different product that better fits your requirements, whatever they may be.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 7 years ago.
Improve this question
I think I summed it up in the title. Regarding the question, I have been evaluating my options for utilities that allow me to craft, capture, and analyze TCP/IP packets. I am very new to network programming and I am still learning as I go, but at this point, I want to write a program that establishes a TCP connection.
Here are my goals (long term to short term):
Deploy and code a system that can establish an ssh connection between two computers behind NATS given their local host names (i.e. feynman.home to feynman.work) and the IP addresses of their routers. I would also like to be able to guide the connection across a set of hops if possible/necessary.
No using third parties or closed source code of any kind. #
Rewrite (and possibly modify) pwnat in a "cleaner" format (i.e. using some well developed library for a high level language.)
Establish ssh connection between two hosts behind the same NAT (using my own code of course.)
Establish TCP connection between two hosts behind the same NAT (using my own code of course.)
I have managed to find netexpect which seemed very promising until it failed to build on my Mac OS X (my computer is going through a glitchy period right now.) Netexpect may well be the best option, but I have come across quite a few others (e.g. scapy and its perl and ruby implementations.) Many of these are not well maintained (e.g. scapy and its perl and ruby implementations.)
So, I thought it would be best to bring the question to stackoverflow (unless there is a better stackexchange I am not aware of.)
*Given the current state of my computer (don't ask) portability is important.
*I would prefer something well maintained/under active developement as to best assure I will have all the tools I will need for my short and long term goals.
*Finally, I would prefer something that uses an interpreted language for a host of reasons ranging from my experience to my preference.
#Yes I am fully aware there are easier ways. I want to do it my way because this just as much a learning experience as it is practical.
I know you are looking for a library on an interpreted language, but libcrafter is very easy to use. Is a C++ library for crafting and parsing network packets. On the future, it will support more protocols.
Most of what you described involving routing the connection between multiple hops/NATs - isn't done in the SSH client at all. It would involve having access to several network routers and setting up all those NATs in advance, then those translations would already happen automatically when the connection is routed through.
Are you talking about proxying your connections through multiple servers? That could be accomplished by a macro that logs in to server A, then automatically invokes ssh again from server A to get to server B and so on.
Could you describe in some more detail what you are trying to accomplish?
Edit: I just read the description of pwnat. That is incredibly proprietary (and won't work in every situation anyway, since many configurations block ICMP completely). If you really wanted to try it out, you'll probably be stuck with C/C++. I don't think Java or .NET gives you the kind of low-level flexibility that you would need to packet craft, for security reasons. Have you looked at Ostinato: http://code.google.com/p/ostinato/wiki/Downloads?tm=2 or Nemesis: http://nemesis.sourceforge.net/
Pretty much everything on windows will use winpcap and on *nix it will use libpcap.
While I haven't tried it, this might work: http://www.codeproject.com/Articles/12458/SharpPcap-A-Packet-Capture-Framework-for-NET
It says it SharpPcap handles interfacing with winpcap... so depending on what they implemented, or whether you can extend that functionality, you may be able to put something together.
Or, in java, you might be able to use something like this as a starting point: http://jpcap.sourceforge.net/
libtins is an open source, multi-platform, C++ library I've been developing for the past year. You can forge, sniff and interpret packets from network interfaces using it. It's very simple to use, and it provides a high level interface so you don't have to worry about endianness, internal protocol implementations, etc.
You can have a look at it at the library's website.
We are thinking about writing a softphone app. It would basically be a component of a system that has calls queued up from a database. It would interface with a LINUX server which has Asterisk installed.
My first question is
Whether we should write the softphone at all or just buy one?
Secondly, if we do,
what base libraries should be use?
I see SIP Sorcery on CodePlex. More than anything, I am looking for a sense of direction here. Any comments or recommendations would be appreciated.
The answer would depend on the capabilities you have in your team and the place you see your core value and the essence of the service you provide.
In most cases, I'd guess that you don't really care about SIP or doing anything fancy with it that require access to its low level. In such a case, I'd recommend getting a ready-made softphone - either a commercial one or an open source one. I'd go for a commercial one, as it will give you the peace of mind as to its stability and assistance with bug fixing and stuff.
To directly answer your question, one of the many open source softphones are likely to fit your needs, and allow slight modifications as needed. Under most open source licenses there is no obligation to distribute your code as long as you only use it internally (do not distribute the binary.)
Trying to guess what you are trying to do, it sounds like a call center like scenario, so one of the many call queue implementations out there might fit your needs.
I had to write an own softphone and I found a great guide how to achieve it. In the guide there are 10 steps provided for having an own softphone (voip-sip-sdk.com on page 272)
I found it useful and maybe you will find it as well.
I would like to ask a question about network communication.
The Question is:
A server uses the socket interface on the Lunix platform,
and a client uses Winock on the Windows platform.
Can they communicate?
Explain briefly.
I guess the answer is NO.
I guess it is due to the compatibility between 2 different socket interface?!
But I am not sure my estimation is right or not.
So, I hope someone could give me some comments about this questions.
Thank you very much!
Not right at all.
The APIs are different, but both sockets create packets written to a standard format described in RFC 793 and lots of subsequent revisions and additions.
Follow that packet format, and implementations written for different platforms and in different languages will talk to each other.
This is the magic of the internet.