A "translated by a human to Ukrainian" version is also available.
Other pages in this site should get you all excited about the sensors and actuators you can put into a control or data logging application. This page addresses some of the options for indirect connections for them to the PC which is the brains behind the system, connections via LAN and WAN.
(Update: May 2015) This page dates from 2005, and some material may be a little dated. If you want to do the sorts of things hinted at here, you might also enjoy my Arduserver page.
If you want to connect reasonably local things via an alternative, non-Ethernet, network, which will save you money (but require more expertise), you should consider the MicroLan, and the 1-Wire chips it supports.
For a "fancy" solution, which connects you to data streams from the internet, which can be generated elsewhere by you, or harvested from the work of kind strangers, there is Pachube. It is sort of a "YouTube for data". I've done a separate page explaining Pachube.
If you want to read sensors, set outputs across a LAN and want a "hobbyist" answer, one source of interfaces accessible across LANs is WizNet. That link will take you to the product page of their, to adapt their online text...
Webserver based IO control module Key Features - Remote I/O Monitoring and Control with Ethernet - 8 Digital Input Ports - 8 Digital Output Ports - 2 Analog Input Ports (12 bit resolution) - 2 Analog Output Ports (12 bit resolution) - Supports Application Program - Supports WebServer
I found several suppliers (search with Google for "WIZ220IO") selling it for a little under $40 (6/10).
For something a little more "consumer oriented" (but more expensive), there is the Poseidon, and similar devices.
I acquired a Poseidon unit in late May 2005 from the HWgroup. This little beauty is a box that you plug into your LAN wherever you wish. Into it you plug one or more temperature sensors (it will take 1-Wire sensors, so "or more" can perhaps be quite a few. It will certainly support up to four. It will take other types too.). You can also connect up to 3 digital inputs. Once you've done that, you can read the temperatures and check the state of the inputs from anywhere on the LAN. You can just plug it in, and use it via a browser, or you can write programs to interact with it. I've written more on my Poseidon experiences for you. I've also produced a page with my independent comments about the HWgroup product line.
Also from the HWgroup, also in late May, I acquired an eight digital in / eight digital out LAN unit. Plug into your LAN wherever you wish, see / control the inputs and outputs via a browser, or you can write programs to interact with it. I've written more on my IO Controller experiences for you. I've also produced a page with my independent comments about the HWgroup product line.
Several years ago, I also had some fun "playing" with another well made device which you can just plug into a LAN, and access via a web browser. It is the IP Power 9212 from Aviosys. I'm told that you can even access it across the internet, if you have the right connections in place. It has 8 relays (essentially an electronically operated switch) which, across the LAN, from your browser, you can turn on or off. It has 8 inputs... 4 resistive, 4 voltage sensing... which you can "read" across the LAN. It is the IP Power 9212, from Aviosys, and you can read more from me about it by clicking here! So far, I have not managed to operate it except "by hand" using a browser. If you have mastered the interface via socket. dll which they supply, PLEASE get in touch. It looks promising, but Aviosys, reasonably- up to a point, are reluctant to support programmers. I've also posted information about a LAN camera from the same source, the IP Kamera. Aviosys seems much less interested in customer support than HW Group.
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