Im in need of a solution, I basically require a way to print from a web page to a printer. But the printer needs to be standalone, either plugging directly into phone line, using a sim card etc. Does anyone know of a good solution for this?
It needs to be cheap to run, setup costs aren't that much of an issue, but obviously the cheaper the better.
If landline is okay, I believe the device you want is an antiquated piece of hardware called a "fax machine"
If wireless on a mobile network, the service plan is more of a cost concern than the hardware, though the two might be bundled together. For example, a company called bug labs is working on some kind of partnership with verizon for connecting their embedded linux device construction kit.
Related
My idea is to have single addressable RGBW LED strips in all my rooms. For the sake of practice and interest, I do not simply want to by some controller, I want to start this project with some custom self-build infrastructure, consisting of some Arduinos and/or raspberry pis. My initial idea was to just setup a simple local server on a raspberry (which controls the arduinos connected to the LEDs) and build myself an app to control the lightning. That part is clear to me and should not be a problem, but I thought it might be a plus to integrate my devices directly to Google Home so I do not need any extra app.
I read through the Smart Home Platform but things are not 100% clear to me. I read things about requirements like public Oauth2 Server. I was wondering, if it is possible to get this working without setting up any server which has to be reached publicly, because otherwise I won't waste time on that topic.
If you want to control your room devices from a smartphone and are satisfied with local operation from few meters away than you should consider BLE on phone and devices.
Obviously, you would need to write your own app, but luckily with BLE you can use publicly available apps such as LightBlu for the dev phase and maybe even for later use (I have not looked into that lately).
What I'm asking here may not be possible at all, due to my lack of knowledge with networks.
I want to start playing around with IOT objects in my house. I would love to be able to control various objects from the touch of a button on my phone.
I have bought a "smart" plug outlet which enables me to turn the power on or off via an app over my home WiFi, however I want to be able to build my own app and control the device exactly how I want to, just for fun.
This app I'm using at the moment comes with the outlet and as far as I can see, it was not meant to be customizable in any way.
My question is, is it possible to figure out the requests being made to and from the device, and create my own API to work with it?
I am a software developer day-to-day however my knowledge in networks is very basic. Any help is really appreciated!
If there is no documented API you can, in theory, to reverse engineer the API using sniffers. If you control the device from your phone you can install sniffers on the phone and see the incoming and outgoing requests. But the bigger problem for you is if there is some kind of security mechanism that the device and the app are implementing. The protocol can be encrypted so you wont be able to understand the network traffic or maybe some kind of key that will allow the device to get orders only from a specific app.
So my suggestion, if you are not experienced with this kind of work is to approach the device vendor and ask them for the API, some vendors would be happy to expose it if you would publish your code and let other customers to use it and expand their product.
I'm looking to establish a connection between my laptop and a remote PC in such a way that I can ping other devices connected to one of its network cards from my laptop.
That might be a little unclear- let me be more specific:
I am a PLC programmer, and my company just migrated to a brand of PLC that requires individual software licenses for each "station." So we're not going to be spending the money for the programming software at each location- instead, each technician will have a laptop, and he can physically visit whichever location needs troubleshooting.
However, that gets to be a lot of travel (international, in some cases), and I'm looking to come up with a way (using a VPN or something) so that I can connect to a PLC remotely.
Our setup is a Windows 7 Industrial PC at the customer's location with two network cards- one is hooked up to the customer's network (and the internet), and the other is hooked into the various PLCs, all with static IPs in the same range. I'm trying to minimize the amount of software I'll have to install/purchase for this project- we already use Teamviewer, but its VPN connection doesn't seem capable of accomplishing what I want (at least, I've never been able to manage a successful ping to one of the PLCs, no matter how much I mess with settings, and their support consists mainly of "buy our newest version").
I've seen lots of posts about this kind of stuff on the internet, but a lot of it seems directed to people who either already know how to set this stuff up and just want to know which software is cheapest, or it is specific to the brand of PLC (I'm using Lenze, which is not very common in english-speaking countries, or at least in america).
Anybody who has managed something like this- I'd really appreciate some sort of walkthrough, or at the very least some pointers in the right direction.
VPN is for TPC/IP communication. Whenever you need layer 2 from ethernet, you're stuck. I know that Step 7 TIA from Siemens can not find for PLCs via VPN. Explaination from support is that searching goes via layer 2. And this list can be made longer.
Most brands can now handle programming via memory cards. Just program local, write it to a memory card and plug it into your PLC.
Just contact the companies and see what they have to offer. The times are still here that PLC brands are fighting for customers. Let them do the work for you and enjoy. It works for our company. :)
I'm currently building a network monitoring system that will notify me if any interface errors or network issues. after building it we would like to be able to test if it works before implementing it to our network, so need a way of simulating network interface errors on a switch or networking device?
I was thinking about cutting ethernet cables or terminating them wrong, but ideally I need soemthing that can create loads of different types of interface errors
any help would be much appreciated
Sean
You could download Nagios which is a powerful, enterprise-class host, service, application, and network monitoring program. Designed to be fast, flexible, and rock-solid stable. Nagios runs on *NIX hosts and can monitor Windows, Linux/Unix/BSD, Netware, and network devices.
you can download other network monitoring systems from sourceforge they have many different network tools written in different languages most of them are open source. you can take notes of their
design and maybe add to the application you building.
if you want to test your application the best thing to do is to tested on real environment, I believe their might be one or two Virtual Lab.
But Ideally I would tested on real interfaces
One of the ways to simulate network failures would be to dynamically change the firewall settings. You can make packets drop, hosts, disappear, etc. This doesn't require any physical damage to anything :)
I want to write a program that programmatically sends faxes. Or receives faxes. But not with a modem. I guess I'm trying to write a fax simulator. Everything that the hardware does, I want to do using software.
There are a billion SO questions on the topic, but they either suggest an online service to use or they point me to a library, which talks to my computer's modem. So here are my specific questions:
When I send a fax, I can hear the warbling on the telephone line. This tells me that my fax machine is generating tones that are consumable by the recipient's. What is that protocol? Is there an RFC which specifies how a "pixel" is converted to a "frequency"? Do the machines communicate back and forth, or is it one-way?
If we can agree that a fax machine translates sound frequencies to images, then one ought to be able to write a program which takes an MP3 of a fax transmission and outputs a graphic. What do I need to know in order to do this?
Are these questions based on any flawed assumptions? Where should I start so that I can accomplish goal #2 from above?
Actually in modem a chip called "DSP => Digital Signal Processing" is responsible to convert audio signals into digital DATA. and same can be done with a software library. there is already an open source DSP library called SpanDSP developed by "Steve Underwood" http://www.soft-switch.org/.
You can build your own application while using SpanDSP library, but it is wise to use some existing implementation of SpanDSP. Currently SpanDSP is implemented in open source FreeSwitch, CallWeaver and Asterisk PBX systems.
But if you only want to send and receive faxes without bothering low level development then try out ICTFAX Open Source FAX system.
The fax specifications you would need are ITU T4 and T30, which costs lots of money and are almost wilfully difficult to understand, and they'll refer you to the various modem standard for how the actual 'warbling' is done.
If you're hoping for something free/easy like an RFC, then you should probably give up now.
If you did want to decode an audio file, you would need to view that as two completely separate tasks - firstly decoding the tones to a data stream (build several soft-modems, for the various ways fax machines can agree to communicate), and then secondly decoding the data-stream to pixels (write a fax machine's software).
You are not fundamentally wrong that a fax machine converts light and dark into sound and then back again, or that it's possible to eavesdrop on a conversation between two fax machines and recover the image (either in real-time or via some kind of capture file, though I'm not sure that MP3 would work), but I suspect you've hugely, hugely underestimated the amount of work involved.
http://en.wikipedia.org/wiki/Fax
has plenty of background.
The ITU protocols are very involved, IIRC the exact specifications are not free.