Wifi: Connecting a Laptop to en embedded system
in [Design]
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From: Charlie E. on 15 Jun 2010 13:51 On Tue, 15 Jun 2010 18:14:29 +0200, "PovTruffe" <PovTache(a)gaga.invalid> wrote: >"Jan Panteltje" <pNaonStpealmtje(a)yahoo.com> a �crit : >> 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. > >The requirements are very low: >1) Just a few bytes (commands) sent to the embedded system once a while. > Thats one way communication but I dont know yet if status data may be > necessary or even usefull (I am just starting to think about the project). >2) Very low speed but reaction time should not be too low. >3) Any interfaces that could be made available on a 16 bit PIC driven board. >4) Very low distance: max 20m (60ft...) >5) This is not a mission critical system > >The embedded system would already have a control panel so the wifi >connection could just be used by some customers who would use their own >laptop. Therefore the laptop could be of any type. My idea is that using wifi >could be the easiest solution for this kind of application (or not?). > >> 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. > >Yes but how many laptops have a serial port nowadays ? >In addition most customers dont even know what a serial port is... > Ok, you can have literally ANYTHING on the PIC24 series, from WiFi, MiWi, etc., the real question here is "What is available on the notebooks?" In most cases, that is going to be WiFi only. They do have full TCP/IP stacks for the PIC24, so that won't be a problem. They are even adding WiFi modules to their product line. Your real questions are the security and interface to the web... Charlie Microchip Design Partner
From: Dave Platt on 15 Jun 2010 14:07 >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. One way would be to use IRDA, which implements a simple networking capability using pulsed IR. Some laptops have IRDA transceivers built in, and for those that don't you can buy an add-on dongle. To the computer (laptop or embedded) IRDA implements a packet-oriented protocol, sitting on top of a high-speed UART, which is itself connected to the IR transceiver. Distances are usually limited to a few feet, with clear line of sight. Another option is to use WiFi, running in "ad hoc" mode. You don't need an access point for this... the systems operate point-to-point. If you've ever seen an "HPSetup" network when you've looked around for a WiFi connection, that's an "ad hoc" network being advertised by an HP laser printer that hasn't yet been configured. I agree that Bluetooth is a workable option as well... a lot of embedded-controller operating systems come with a Bluetooth stack these days. If you don't absolutely require wireless, then a USB connection at the laptop end would probably be the way to go. Use a USB-to-serial interface chip in the embedded system, hook it to a UART on the embedded controller, and you've got a connection that almost any laptop can plug into. -- Dave Platt <dplatt(a)radagast.org> AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!
From: Dave Platt on 15 Jun 2010 14:14 In article <hv8cpp$ng3$1(a)news.eternal-september.org>, hamilton <hamilton(a)nothere.com> wrote: >So would two Bluetooth devices be cheaper that one embedded WiFi ?? I see USB-to-BlueTooth dongles selling online for under $2 in single quantities, and under a dollar (free shipping) on eBay. -- Dave Platt <dplatt(a)radagast.org> AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!
From: Proteus IIV on 15 Jun 2010 17:37 On Jun 15, 11:43 am, FatBytestard <FatBytest...(a)somewheronyourharddrive.org> wrote: > On Tue, 15 Jun 2010 12:12:34 +0200, "PovTruffe" <PovTa...(a)gaga.invalid> > wrote: > > >Hi, > > >Say you want to design an embedded system that any laptop can > >connect to without any Wifi network available. Is that possible ? > > >Just a point to point communications would be required, not really > >a full featured wireless network. A laptop would just sent a few > >simple commands to the embedded system. > > >Maybe BlueTooth would be more appropriate for this application but > >this would require adding a costly dongle to most laptops. > > >Or Zigbee ? > > What you can do... > > You make it a device on the laptop that takes control of it. So, > either it dumb logs onto any laptop that OKs an 'install' of it, or you > make it a router itself, and any authenticated user gets to log onto it. > > What you should do... > > Instead of making an embedded device, you should just hack an existing > device, like an old WRT54G router, that runs Linux and has all the > authentication software and such already built into the Linux that runs > on it. All fully open and fuckable. IS THERE SOMETHING WRONG WITH YOU ? WHAT YOU SHOULD DO...... STOP THINKING YOU THAT YOU KNOW THE DYNAMICS OF PROBLEM SOLVING AMONG HUMANS AND EVEN IF YOU HAVE THE SURE FIRE SOLUTION DON'T TROLL YOU WAY INTO OTHERS LIVES SHARE COURTEOUSLY AND RESPECTFULLY OR YOU CLEAN PIPES FOR A LIVING AND STOP GIVING DIRTY ADVICE OR YOU'LL GET DIRTY RESULTS I AM PROTEUS
From: hamilton on 15 Jun 2010 18:31
On 6/15/2010 12:14 PM, Dave Platt wrote: > In article<hv8cpp$ng3$1(a)news.eternal-september.org>, > hamilton<hamilton(a)nothere.com> wrote: > >> So would two Bluetooth devices be cheaper that one embedded WiFi ?? > > I see USB-to-BlueTooth dongles selling online for under $2 in single > quantities, and under a dollar (free shipping) on eBay. > How about the embedded side ? Whats a serial Bluetooth module cost these days ?? Is anyone using one ? hamilton |