I'm making a distributed sensor network. The basic architecture of my network is to have several slave nodes (up to about 10) reporting back to a master node on a regular basis.
I'm looking for a software framework that I can use for this, so far I have thought of
corba
pubsubhubub
xmtp
making my own
I have some basic requirements (like basic security, fault awareness)
Anyone have any suggestions?
In specific answer to your question, TinyOS provides a lot of what you'll need.
There's quite a large body of academic work on getting these up and running, especially combining agent-based infrastructures with sensor networks -- take a look on Google Scholar for example.
There are also some very good links on Wikipedia.
Are you specifically interested in an OS to run on your sensors, or something at higher level that plugs into some sensor infra you already have? Are you intending to build your own kit, or work on something that already exists (e.g. BTNode)?
You can also use RL-ARM or FreeRTOS if you wanted to use micro controllers for your project. also in the network layer you can use lwip.
there are many other libraries both free and open source in case if you want to use ARM based micro controllers.
Related
I am trying to write a Gatan DigitalMicrograph script to control the tilting of incident electron beam before and after a specimen. I think that the values of pre-specimen lens system can be got and changed by using commands such as EMGetBeamTilt, EMSetBeamTilt and EMChangeBeamTilt. However, I don't know how to get or control the status of the post-specimen lens system such as a projector lens. What command or code should be written in order to control the projector lens system?
It will be appreciated if you share some wisdom. Thank you very much in advance.
Unfortunately, only a limited number of microscope hardware components can be accessed by DM-script via a generalized interface. The generalized commands communicate to the microscope via a software interface which is implemented by the microscope vendor, so that the exact behaviour of each command (i.e. which lenses are driven when a value is changed) lies completely within the control of the microscope software and not DM. Commands to access specific lenses or microscope-specific controls are most often not available.
All available commands, while they can be found in earlier versions often as well, are officially supported and documented since GMS 2.3. You will find the complete list of commands in the F1 help-documentation (on online-systems):
I'm learning electronics/microcontroller programming through TI-MSP430 Launchpad(Energia) and Arduino.
Both are based on wiring framework, and very good place to start for a beginner like me.
Now as I'm forwarding in my learning, I'm thinking to explore more and want to do a real world project. My project can be easily done on both above mentioned platforms, but I want to use STM8S-Discovery(Dev board or STM8S series MCU) for this but there is no wiring framework for STM8S as far as I know and I don't want to use if there is any.
What other skills/information I need to migrate from these wiring framework based platform to real world microcontroller projects?
Thanks in advance for inputs!
The datasheet and user's guide will be your best friend. Be sure to look at programming examples for that device as well. Typically you'll need to do the following:
Initialize clock system and setup peripherals and I/O. (Frameworks generally do all this for you). Read some of the actual code behind the scenes of Energia to see how it actually works.
Once the main hardware is initialized, setup your business logic (variables).
Loop indefinitely (like most embedded systems do)... while (true) anyone?
I hope that helps.
I contributed the A110LR09 Booster Pack library for Energia. Take a look at the source code if you're interested with how to write specific device drivers in C/C++ for the MSP430.
I am a newbie with Xen.I want to know how does Xen work.
It's really a puzzle when facing the code and I don't know where to start.
Are there some easy articles for me?
Since you mention looking at the code, I assume you want to understand the technical details of Xen and not just merely how to start a VM.
As with all problems, start with something simple and then work your way up. Some pointers:
Be sure to have the prerequisite experience under your belt. In particular, strong C and Linux affinity, but also x86 paging and virtualized memory workings.
Make sure you have a sound grasp of the general Xen architecture. For instance, paravirtualized versus hardware-supported virtualization, the special role of the management domain (Dom0) compared to unprivileged domains (DomU), etc.
Investigate the the Xen components running in Dom0:
The Xen control library (libxc) which implements much of the logic relating to hypercalls and adds sugar around these (look in tools/libxc).
The swiss army knife for administrating Xen, namely the Xen light library (libxl). This library replaces the deprecated xm tool with the xl tool and takes care of all your maintenance tasks such as starting/stopping a VM, listing all running VMs, etc. For all these operations, it works in tandem with the aforementioned libxc. (Libxl lives in tools/libxl.)
The Xenstore is a tree-like data structure from which all running domains can retrieve and store data. This is necessary since all I/O goes through Dom0 (not the hypervisor!), and domains need to communicate with Dom0 how they are going to pass I/O along. (Look in tools/xenstore.) You can inspect the Xenstore with a tool such as xenstore-ls.
the blkback/netback kernel drivers which pass the data over shared channels to the VMs. (You will find these drivers in a recent Linux kernel (e.g. >= v3.0) that has so-called PVOPS support).
Take a look at the console daemon (tools/console). Note that sometimes the Qemu console is actually used. Qemu also comes in the pictures as a default backend for if you choose a file-backed virtual storage for a VM.
Experiment with the 'Xen-way' of inter-VM communication: Grant tables, event channels and the Xenstore. With these fundamentals you can create your own shared channel between VMs. You can do this, for example, with writing a kernel module that you use in two domains to let them talk to each other.
I can also give some pointers in the source that you can check out:
xen/xen/include/public/xen.h will give you a list of all the hypercalls with comments what they do.
xen/xen/include/xen/mm.h gives you an introduction to the different memory terminology used by Xen (i.e., real versus virtualized addresses and page numbers). If you don't grasp these differences, then reading the hypervisor code will surely be frustrating.
xen/xen/include/asm-x86/config.h gives an overview of the memory layout of Xen.
xen/tools/libxc/xenctrl.h exports a large list of interesting domain control operations, which gives an abstract view of task division between Dom0 and the hypervisor.
Last but not least, the book 'The Definitive Guide to the Xen Hypervisor' by David Chisnall comes highly recommended. It covers all these topics and more in a thorough, technical fashion with plenty of code examples.
The Xen wiki and developer mailing lists are also a great resource for understanding Xen.
If you have a more specific question, then I can give you a more specific answer.
Here are few links which will guide you with ZEN Start up.Hope they will be useful.
http://www.howtoforge.com/howtos/virtualization/xen
http://wiki.xen.org/wiki/Category:HowTo
http://wiki.debian.org/Xen
For me, that is the best and more concrete tutorial with examples and step by step to start. I used it when I started.
Then you can read a lot more on Xen documentation itself or some books but as a starting point that allows you to easily install and test Xen, I choose that tutorial from Debian Wiki.
If you just want an overview, you may read this: http://wiki.xenproject.org/wiki/Xen_Project_Beginners_Guide.
This will introduce you to Xen hypervisor, suggest configuration to set up virtual machines, provide information about the networking and finally have details about tools for the management of virtual machines.
This documentation is to get the Xen specifically on ubuntu (Most importantly, it works!)
https://help.ubuntu.com/community/Xen
===
However, if you want to go to the next level and understand the working of Xen; Xen architecture, memory management, device management, CPU scheduling etc., I would recommend reading the book "The Definitive Guide to the Xen Hypervisor".
Voxeo provide a free IVR for development purposes, but I was wondering if there is a much simpler form of test IVR, perhaps which runs on the local machine and uses your microphone and speakers instead of the telephony network?
You should be able to do this with any VoiceXML IVR that supports SIP in combination with a softphone. There are a variety that do, including Voxeo. For a lower cost solution, you might be able to do something with Asterisk and the VXI* based browser that runs on the platform.
Note, be aware that VoiceXML browsers vary from platform to platform. This may or may not be an issue for you when developing and testing your application. You can write fairly portable applications with just a bit of experience across platforms, but if you are new to VoiceXML, knowing how just one platform has implemented the specification can get you into trouble.
As a different approach, you could look at Voiyager that also allows you to drive the call flow with text input or via a programming interface. Disclaimer: I am part of the development team and company that produces Voiyager.
I would like to develop a Network Inventory application that works on any operating system.
Reports on every possible resource attacehd to a network.
Reports all pertinent details of hardware and software.
Thats (and i hate to use the phrase) my "End Game".
However I am running before i can crawl here.
I have no experience of this type of development, e.g. discovering a computers hardware and software settings.
I've spent almost two weeks googling and come up short! :-(.
So I am turning to you to ask these questions:-
My first step is to find an existing open source project i can incorporate into my own code that extracts the fine grained details i am after, e.g. EVERYTHING there is to know about the hardaware and software on a single machine.
Does this project exist? or do i have to develop that first?
Have i got to write all this in C?
I am guessing getting this information about a computer is going to be easier than for printers, scanners, routers etc... e.g. everything else you would find attached to a network.
Once i have access to a single computers details i then need to investigate how i can traverse an entire newtork of printers, scanners, routers, load balancers, switches, firewalls, workstations, servers, storeage devices, laptops, monitors, the list goes on and on
One problem i have is i dont have a 1000 machine newtork to play on!
Is there any such resource available on theinternet? (is that a silly question?)
Anywho, if you dont ask you wont find out!
One aspect iam really looking forward to finding out how to travers the entire network,
should i be using TCP/IP for this?
Whats a good site, blog, usergorup, book for TCP/IP development?
How do i go about getting through firewalls?
How many questions can i ask in one go? :-)
My previous question on this topic ended up with PYTHON being championed as the language/script to go with to develop this application in.
Having looked at a few PYTHON examples they all seemed to be related to WINDOWS networks
and interrogating Windows Management Instrumentation (WMI). I had the feeling you cant rely on whats in WMI, and even if you can that s no good for UNIX netwrks.
Surely there exist common code for extracting hardware and software details from a computer? Why cant i find it on the internet?
Pease help?
Theres no prizes though :-(
Thanks in advance
I would like to appologise if i have broken forum rules or not tried hard enough on my own before asking for assistance.
I just would like to start moving forward with this as its one of the best projects i have been involved with.
I am inspired by the many differnt number of challenges involved and that if i manage to produce a useful application at the end of it it would hopefully be extremely helpful to many people.
That sit
Thanks in advance
DD
as a software vendor of a discovery solution, I can just say: Respect, that you want to start a new one :-). Just in case you are interested in what it could look like: http://www.jdisc.com
Now to some of our experience:
Programming Language:
I wouldn't write it in C. Use Java or .NET. Those languages have great advantages when it comes to tracking down errors or problems. For instance, in Java (and I guess also in .NET), you can see the stack trace when something is failing. For some pieces of code (e.g. WMI access), you might need to use C++ or C (e.g. access to native APIs from Microsoft). Use a native interface or a COM bridge from Java. In .NET, it should even be easier to access the Windows APIs).
Devices:
well, network printers, router, and switches are actually easier to discover. They usually expose their information via SNMP. SNMP is pretty easy to use and pretty robust. Getting information from Windows (or even Unix) systems is a bit trickier. Protocols can be blocked, misconfigured, messed up... We had cases, where WMI was simply hanging when requesting data from a remote device.
Test Devices:
Since we are also a smaller company, we also do not have 1000 different devices to test with. But, there are some things that might help:
a) For SNMP devices use a SNMP simulator. We use MIMIC 9.0 from Gambit Solutions and we are pretty happy with it. You can import SNMP walks from network devices and simulate the device as if it would be in your network.
b) Secondly, use virtualization whenever possible. With VMware, you can install Windows, Linux, or even Solaris. We also use a project called GNS3 to emulate Cisco Routers, Firewalls or Juniper routers.
c)You can test the rest of the devices only, if you have a customer that helps you with testing and implementing new devices.
This are just some ideas to start with. But I have to tell you, that it is not trivial and it takes a lot of time....
Hope that you got some ideas to start with...
I don't know that it's open source, but we use Spiceworks (http://www.spiceworks.com) here as an IT management platform. You may get some use out of exploring that.