Post by thread:[PIC] WiFi & PI

On 5/24/06, alan smith <spam_OUTmicro_eng2TakeThisOuTyahoo.com> wrote: > Client has asked....possibility of doing a WiFi with a PIC. Well...the project in discussion is for a large greenhouse facility and monitoring temps and other stuff. I suggested something like zigbee or even Lynx type RF, but he thinks that WiFi would be an option since he wants a web based interface to monitor and control. > > Anyone ever come across a 802.11b/g simple interface? I am thinking that there is alot of overhead involved to setup each node with its IP address, etc. The interface from the PIC can be serial of some flavor, but I need the solution to be cheap and robust as well. > It's crazy overkill, but you could use the Linksys WRT54GL router. It runs Linux, and has all that Wi-Fi stuff built in. $70 each. Regards, Mark markrages@gmail -- You think that it is a secret, but it never has been one. - fortune cookie

On 5/24/06, alan smith <micro_eng2KILLspamyahoo.com> wrote: > Client has asked....possibility of doing a WiFi with a PIC. My opinion after some time struggling with WIMAX with a real DSP core (2.4GHz): WIFI with a PIC at 54Mbps 802.11b/g = zero chances if the transciever hardware is not doing everything and the PIC almost nothing. Doing Zigbee at slow speed with a PIC have 100% chance if a good transciever chip is chosen. greetings, Vasile Well...the project in discussion is for a large greenhouse facility and monitoring temps and other stuff. I suggested something like zigbee or even Lynx type RF, but he thinks that WiFi would be an option since he wants a web based interface to monitor and control. > > Anyone ever come across a 802.11b/g simple interface? I am thinking that there is alot of overhead involved to setup each node with its IP address, etc. The interface from the PIC can be serial of some flavor, but I need the solution to be cheap and robust as well. > > > --------------------------------- > Love cheap thrills? Enjoy PC-to-Phone calls to 30+ countries for just 2¢/min with Yahoo! Messenger with Voice. >

Well considering you can run wifi on a PC with less than 2.4GHz CPU clock, I'd say that the only thing you've proven is that you can't bit-bang wireless. But using dedicated hardware to do it, it's certainly possible (as olin has stated). - Marcel On 5/24/06, Kevin Lineberry <.....kelineberryKILLspam.....yahoo.com> wrote: > > This is not possible. > Wifi is 2.4 GHz > Pic is less than 100MHz > Therefore, you cannot implement a wifi device with a pic. > > > --------------------------------- > Love cheap thrills? Enjoy PC-to-Phone calls to 30+ countries for just > 2¢/min with Yahoo! Messenger with Voice. >

On 5/24/06, alan smith <EraseMEmicro_eng2spam_OUTTakeThisOuTyahoo.com> wrote: > OK...I wasnt sure if you were doing a chip level solution, or off the shelf (latter obviously and easier). > > Olin Lathrop <olin_piclistspam_OUTembedinc.com> wrote: alan smith wrote: > > Whats your estimated hardware costs for the WiFi portion? > > I don't know since it has never been broken out. The parts we are using > that are only for WiFi are pretty much just the compact flash connector and > the compact flash WiFi card. Yes, but this means the RF project belongs to someone else, you have no control on that side and you depend from those RF design, BER, SNR, etc, etc, etc. As long you've change the RF part you must made changes in your project too, including firmeare because there are many differences in RF desighns even the connector is the same. And again I don't think you're able to use the entire bandwith (54Mbps) that 802.11 a/g recommend. greetings, Vasile > > > ****************************************************************** > Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC > consultant in 2004 program year. http://www.embedinc.com/products > -

> > And again I don't think you're able to use the entire bandwith > (54Mbps) that 802.11 a/g recommend. I never knew that 802.11a/g recommended a certain bandwidth usage... I always thought that this was up to the person. You mean I will have to keep sending data/receiving data with my laptop continuously, or I am not within recommendations of the standard? As far as I know, 802.11a rarely manages to get 54 Mbps anyway, it peaks more around 20-30. But maybe you meant that since the PICmicro can't provide 54 Mbps, the system wouldn't be able to transmit at that speed either. However, the configuration as described, with the WiFi system on an SD card, should easily be able to send the data at any speed (also 54 Mbps). There might just be a larger gap between the packets if a PICmicro is providing the data, and the PICmicro might have to drop some packets if it is sent a continuous data stream at that speed. Greetings, Maarten Hofman.

Vasile Surducan wrote: >> I don't know since it has never been broken out. The parts we are using >> that are only for WiFi are pretty much just the compact flash >> connector and >> the compact flash WiFi card. > > Yes, but this means the RF project belongs to someone else, Exactly! Getting all those details right and properly certified by regulatory agencies is a *major* job. The volumes of compact flash Wifi cards are high enough that you can get them for a very reasonable markup over production cost. You really really don't want to try designing your own just to have WiFi connectivity in a bigger product. > you have > no control on that side and you depend from those RF design, BER, SNR, > etc, etc, etc. Right. Someone else has already invented the wheel, designed a product around it, dealt with the wheel police, and is producing them in volume at a good price. Since my end product just uses wheels to get a bigger job done, it would be really silly to try and design and produce my own. > As long you've change the RF part you must made changes in your > project too, including firmeare because there are many differences in > RF desighns even the connector is the same. I'm not quite sure what you are saying, but we are working with CF cards that all use the same popular chipset. > And again I don't think you're able to use the entire bandwith > (54Mbps) that 802.11 a/g recommend. No, and I don't want to. The overall datarate of this product is something a PIC can handle. The reason for WiFi is easier and cheaper installation. ****************************************************************** Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC consultant in 2004 program year. http://www.embedinc.com/products

On 5/25/06, Olin Lathrop <@spam@olin_piclistKILLspamembedinc.com> wrote: {Quote hidden}> Vasile Surducan wrote: > >> I don't know since it has never been broken out. The parts we are using > >> that are only for WiFi are pretty much just the compact flash > >> connector and > >> the compact flash WiFi card. > > > > Yes, but this means the RF project belongs to someone else, > > Exactly! Getting all those details right and properly certified by > regulatory agencies is a *major* job. The volumes of compact flash Wifi > cards are high enough that you can get them for a very reasonable markup > over production cost. You really really don't want to try designing your > own just to have WiFi connectivity in a bigger product. > > > you have > > no control on that side and you depend from those RF design, BER, SNR, > > etc, etc, etc. > > Right. Someone else has already invented the wheel, designed a product > around it, dealt with the wheel police, and is producing them in volume at a > good price. Since my end product just uses wheels to get a bigger job done, > it would be really silly to try and design and produce my own. > > > As long you've change the RF part you must made changes in your > > project too, including firmeare because there are many differences in > > RF desighns even the connector is the same. > > I'm not quite sure what you are saying, but we are working with CF cards > that all use the same popular chipset. Intercept the RF with an atenna. Connect the antenna with a spectrum analyzer (a real one not those made by PCMCIA WIFI card + a software program). Change the CF WIMAX card and see what you'll see. It's the same CF card, the same 802.11 standard and the way of flowing packs are completely different, the SNR (or SFDR) is different, the EVM is different and the efect you may see is just one: this CF works, the other CF works too but slowly, and closer to the router... Vasile {Quote hidden}> > > And again I don't think you're able to use the entire bandwith > > (54Mbps) that 802.11 a/g recommend. > > No, and I don't want to. The overall datarate of this product is something > a PIC can handle. The reason for WiFi is easier and cheaper installation. > > > ****************************************************************** > Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC > consultant in 2004 program year. http://www.embedinc.com/products > -

On 5/27/06, Vasile Surducan <KILLspampiclist9KILLspamgmail.com> wrote: {Quote hidden}> On 5/25/06, Olin Lathrop <RemoveMEolin_piclistTakeThisOuTembedinc.com> wrote: > > Vasile Surducan wrote: > > >> I don't know since it has never been broken out. The parts we are using > > >> that are only for WiFi are pretty much just the compact flash > > >> connector and > > >> the compact flash WiFi card. > > > > > > Yes, but this means the RF project belongs to someone else, > > > > Exactly! Getting all those details right and properly certified by > > regulatory agencies is a *major* job. The volumes of compact flash Wifi > > cards are high enough that you can get them for a very reasonable markup > > over production cost. You really really don't want to try designing your > > own just to have WiFi connectivity in a bigger product. > > > > > you have > > > no control on that side and you depend from those RF design, BER, SNR, > > > etc, etc, etc. > > > > Right. Someone else has already invented the wheel, designed a product > > around it, dealt with the wheel police, and is producing them in volume at a > > good price. Since my end product just uses wheels to get a bigger job done, > > it would be really silly to try and design and produce my own. > > > > > As long you've change the RF part you must made changes in your > > > project too, including firmeare because there are many differences in > > > RF desighns even the connector is the same. > > > > I'm not quite sure what you are saying, but we are working with CF cards > > that all use the same popular chipset. > > > Intercept the RF with an atenna. Connect the antenna with a spectrum analyzer > (a real one not those made by PCMCIA WIFI card + a software program). > Change the CF WIMAX card WIFI (not yet WIMAX) and see what you'll see. {Quote hidden}> It's the same CF card, the same 802.11 standard and the way of flowing packs > are completely different, the SNR (or SFDR) is different, the EVM is > different and the efect you may see is just one: this CF works, the > other CF works too but > slowly, and closer to the router... > > Vasile > > > > > > > And again I don't think you're able to use the entire bandwith > > > (54Mbps) that 802.11 a/g recommend. > > > > No, and I don't want to. The overall datarate of this product is something > > a PIC can handle. The reason for WiFi is easier and cheaper installation. > > > > > > ****************************************************************** > > Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC > > consultant in 2004 program year. http://www.embedinc.com/products > > --