Wifi: Connecting a Laptop to en embedded system
in [Design]
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From: PovTruffe on 15 Jun 2010 11:12 "D Yuniskis" <not.going.to.be(a)seen.com> a �crit : > PovTruffe wrote: >> "D Yuniskis" <not.going.to.be(a)seen.com> a �crit : >>> Um, serial port? (IrDA if you insist on "wireless") >> >> It has to be wireless for this application. As far as I know not so many >> laptops are equiped with IrDa where the vast majority are wifi enabled. > > Use an IrDA dongle -- via a serial port, parallel port, USB serial, > etc. It was my first idea to plug some kind of hardware but I thought maybe there was a better solution without having to add anything... > If you want to use WiFi, then configure for an ad hoc network > (assuming your embedded system wants to bear the cost of WiFi) There is no such thing as a wifi network (as I already explained...) unless I create one with the embedded system I need to control. Maybe there is no need for a so called network for point to point communication. I dont know anything about the wifi standard and so dont have any preconceived ideas of what is possible or not.
From: Jan Panteltje on 15 Jun 2010 11:26 On a sunny day (Tue, 15 Jun 2010 17:12:58 +0200) it happened "PovTruffe" <PovTache(a)gaga.invalid> wrote in <4c179880$0$5562$426a74cc(a)news.free.fr>: >There is no such thing as a wifi network (as I already explained...) unless I >create one with the embedded system I need to control. Maybe there is no >need for a so called network for point to point communication. I dont know >anything about the wifi standard and so dont have any preconceived ideas >of what is possible or not. Questions you need to answer here first: 1) Does it need 1 way or 2 way communication. 2) What speed 3) What interfaces are available on the embedded system, and what interfaces are available on the PC. 4) Distance 5) Reliability. For example for a one way low bitrate short distance you can hang a 430 MHz module on the serial port, and dream up some protocol.
From: FatBytestard on 15 Jun 2010 11:37 On Tue, 15 Jun 2010 17:12:58 +0200, "PovTruffe" <PovTache(a)gaga.invalid> wrote: >"D Yuniskis" <not.going.to.be(a)seen.com> a �crit : >> PovTruffe wrote: >>> "D Yuniskis" <not.going.to.be(a)seen.com> a �crit : >>>> Um, serial port? (IrDA if you insist on "wireless") >>> >>> It has to be wireless for this application. As far as I know not so many >>> laptops are equiped with IrDa where the vast majority are wifi enabled. >> >> Use an IrDA dongle -- via a serial port, parallel port, USB serial, >> etc. > >It was my first idea to plug some kind of hardware but I thought maybe >there was a better solution without having to add anything... > >> If you want to use WiFi, then configure for an ad hoc network >> (assuming your embedded system wants to bear the cost of WiFi) > >There is no such thing as a wifi network (as I already explained...) unless I >create one with the embedded system I need to control. Maybe there is no >need for a so called network for point to point communication. I dont know >anything about the wifi standard and so dont have any preconceived ideas >of what is possible or not. > You have the Wi-Fi device inside the embedded product become a client to a Wi-Fi router, and your PC also becomes a client to that router, and then logs onto the embedded device's user interface 'conole' while on that local net.
From: FatBytestard on 15 Jun 2010 11:43 On Tue, 15 Jun 2010 12:12:34 +0200, "PovTruffe" <PovTache(a)gaga.invalid> wrote: >Hi, > >Say you want to design an embedded system that any laptop can >connect to without any Wifi network available. Is that possible ? > >Just a point to point communications would be required, not really >a full featured wireless network. A laptop would just sent a few >simple commands to the embedded system. > >Maybe BlueTooth would be more appropriate for this application but >this would require adding a costly dongle to most laptops. > >Or Zigbee ? > What you can do... You make it a device on the laptop that takes control of it. So, either it dumb logs onto any laptop that OKs an 'install' of it, or you make it a router itself, and any authenticated user gets to log onto it. What you should do... Instead of making an embedded device, you should just hack an existing device, like an old WRT54G router, that runs Linux and has all the authentication software and such already built into the Linux that runs on it. All fully open and hackable.
From: D Yuniskis on 15 Jun 2010 12:14
PovTruffe wrote: > "D Yuniskis" <not.going.to.be(a)seen.com> a �crit : >> PovTruffe wrote: >>> "D Yuniskis" <not.going.to.be(a)seen.com> a �crit : >>>> Um, serial port? (IrDA if you insist on "wireless") >>> It has to be wireless for this application. As far as I know not so many >>> laptops are equiped with IrDa where the vast majority are wifi enabled. >> Use an IrDA dongle -- via a serial port, parallel port, USB serial, >> etc. > > It was my first idea to plug some kind of hardware but I thought maybe > there was a better solution without having to add anything... > >> If you want to use WiFi, then configure for an ad hoc network >> (assuming your embedded system wants to bear the cost of WiFi) > > There is no such thing as a wifi network (as I already explained...) unless I You can use WiFi in "infrastructure" mode or "ad-hoc". Infrastructure mode has all of your WiFi devices talking to (and *thru*) an "access point" (which is often part of a wireless router, bridge, etc.). Think of infrastructure as a star topology -- all your wireless devices talk to the access point in much the same way as a *wired* network has its devices all connecting to a *hub* (switch). Ad-hoc mode has your WiFi devices talking to each other *directly*. Think of this as more of a mesh -- each device talks *directly* to every device that it wants to communicate with WITHOUT the presence/intervention of an "access point" to coordinate those things. I.e., you can have a "wifi network" with just two wifi devices (and *no* access point) in much the same way that you can have a *wired* network with just two devices (and no hub/switch). [though the analogy breaks down once you go to more than 2 devices since you can't just wire together N wired devices whereas you *can* wireLESS together N WiFi devices!] > create one with the embedded system I need to control. Maybe there is no > need for a so called network for point to point communication. I dont know > anything about the wifi standard and so dont have any preconceived ideas > of what is possible or not. |