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.
---------------------------------
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alan smith 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.
This is doable. One of my current projects includes WiFi from a 18F6527.
> I am thinking
> that there is alot of overhead involved to setup each node with its IP
> address, etc.
There are several things to configure, including things like the WEP key to
use. IP address can be static or from DHCP.
******************************************************************
Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC
consultant in 2004 program year. http://www.embedinc.com/products
>-----Original Message-----
>From: spam_OUTpiclist-bouncesTakeThisOuTmit.edu [.....piclist-bouncesKILLspam@spam@mit.edu]
>Sent: 24 May 2006 16:17
>To: Microcontroller discussion list - Public.
>Subject: [PIC] WiFi & PIC
>
>
>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.
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Whats your estimated hardware costs for the WiFi portion?
Olin Lathrop <olin_piclistKILLspamembedinc.com> wrote: alan smith 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.
This is doable. One of my current projects includes WiFi from a 18F6527.
> I am thinking
> that there is alot of overhead involved to setup each node with its IP
> address, etc.
There are several things to configure, including things like the WEP key to
use. IP address can be static or from DHCP.
******************************************************************
Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC
consultant in 2004 program year. http://www.embedinc.com/products
On Wed, 24 May 2006 09:19:03 -0700 (PDT), you wrote:
>Whats your estimated hardware costs for the WiFi portion?
>
>Olin Lathrop <.....olin_piclistKILLspam.....embedinc.com> wrote: alan smith 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.
Wifi would probably overkill for this - a more appropriate way may be low cost sensor/transmitters
on one of the unlicensed UHF bands sending short packets every few minutes to one or more receivers,
depending on distance - the receiver could either be a PC or a data concentrator that bulks up the
data to send via wifi/GSM/GPRS etc.
I totally agree. But he wants to know why not use it...so, aside from the firmware overhead to support it, like to estimate the cost differences as well.
>Whats your estimated hardware costs for the WiFi portion?
>
>Olin Lathrop wrote: alan smith 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.
Wifi would probably overkill for this - a more appropriate way may be low cost sensor/transmitters
on one of the unlicensed UHF bands sending short packets every few minutes to one or more receivers,
depending on distance - the receiver could either be a PC or a data concentrator that bulks up the
data to send via wifi/GSM/GPRS etc.
>-----Original Message-----
>From: piclist-bouncesspam_OUTmit.edu [@spam@piclist-bouncesKILLspammit.edu]
>Sent: 24 May 2006 18:08
>To: Microcontroller discussion list - Public.
>Subject: Re: [PIC] WiFi & PIC
>
>
>I totally agree. But he wants to know why not use it...so,
>aside from the firmware overhead to support it, like to
>estimate the cost differences as well.
>
How about using cheap unlicensed transceivers in the sensors that talk to a wifi equiped base-station? This could be an embedded PC to simplify code development and gives the wireless web browser access that he wants.
Regards
Mike
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Mike Harrison wrote:
> On Wed, 24 May 2006 09:19:03 -0700 (PDT), you wrote:
>
>
>> Whats your estimated hardware costs for the WiFi portion?
>>
>> Olin Lathrop <KILLspamolin_piclistKILLspamembedinc.com> wrote: alan smith 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.
>>>
>
> Wifi would probably overkill for this - a more appropriate way may be low cost sensor/transmitters
> on one of the unlicensed UHF bands sending short packets every few minutes to one or more receivers,
> depending on distance - the receiver could either be a PC or a data concentrator that bulks up the
> data to send via wifi/GSM/GPRS etc.
>
>
I agree. These tiny transceivers operate in the 433Mhz band, and are
quite reliable within 1/4mile. A PIC would provide packeting for
each data transfer (start char + data + CRC + term char) and another PIC
would unwrap the data and stuff it into a host PC through a
serial port. This would be very inexpensive, just a few dollars per
station. You could make it even cheaper by sending the packet only
at random intervals; for example, if the intent was to poll 16 stations
every minute, you could packet data for the last 3 intervals, then
send it at RANDOM intervals once a minute. Its always possible that two
stations would send on top of each other, but since the data
is triplicated, nothing will be lost. The receiving station would simply
receive packets and install them into a database, and toss duplicated
data. To make this work, the packet length has to be short and the
interval must have a lot of dead air. Even more reliable if the interval
is longer, such as 15 minutes. A simple encryption scheme can be
devised, such as substitution cypher, bit rotation, etc.
I hope I didn't get too far off the subject.
In general, I am not enthused about PC wireless schemes. I and some
associates looked into these for a police data dump station, and
the results were NOT heartwarming; not one method was free from hacking.
Personally, I think that IEEE803 etc was a plot hatched by
the NSA/IRS/FBI cabal to easily read everybody's computers by simply
parking in the front driveway and hacking in. It is INCREDIBLY
easy to hack.
I agree, there's no need to burden each sensor with the cost/complexity of
wi-fi.
Just use aloha protocol with error checking, and at some central point, do
the internet interface once.
part 0 44 bytes his is a multi-part message in MIME format. part 1 2827 bytes content-type:text/plain; charset=ISO-8859-1; format=flowed (decoded 7bit)
> Mike Harrison wrote:
>
>>On Wed, 24 May 2006 09:19:03 -0700 (PDT), you wrote:
>>
>>
>>
>>>Whats your estimated hardware costs for the WiFi portion?
>>>
>>>Olin Lathrop <spamBeGoneolin_piclistspamBeGoneembedinc.com> wrote: alan smith 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.
>>>>
>>
>>Wifi would probably overkill for this - a more appropriate way may be low cost sensor/transmitters
>>on one of the unlicensed UHF bands sending short packets every few minutes to one or more receivers,
>>depending on distance - the receiver could either be a PC or a data concentrator that bulks up the
>>data to send via wifi/GSM/GPRS etc.
>>
>>
>
> I agree. These tiny transceivers operate in the 433Mhz band, and are
> quite reliable within 1/4mile. A PIC would provide packeting for
> each data transfer (start char + data + CRC + term char) and another PIC
> would unwrap the data and stuff it into a host PC through a
> serial port. This would be very inexpensive, just a few dollars per
> station. You could make it even cheaper by sending the packet only
> at random intervals; for example, if the intent was to poll 16 stations
> every minute, you could packet data for the last 3 intervals, then
> send it at RANDOM intervals once a minute. Its always possible that two
> stations would send on top of each other, but since the data
> is triplicated, nothing will be lost. The receiving station would simply
> receive packets and install them into a database, and toss duplicated
> data. To make this work, the packet length has to be short and the
> interval must have a lot of dead air. Even more reliable if the interval
> is longer, such as 15 minutes. A simple encryption scheme can be
> devised, such as substitution cypher, bit rotation, etc.
>
> I hope I didn't get too far off the subject.
>
> In general, I am not enthused about PC wireless schemes. I and some
> associates looked into these for a police data dump station, and
> the results were NOT heartwarming; not one method was free from hacking.
> Personally, I think that IEEE803 etc was a plot hatched by
> the NSA/IRS/FBI cabal to easily read everybody's computers by simply
> parking in the front driveway and hacking in. It is INCREDIBLY
> easy to hack.
>
> --Bob
part 2 375 bytes content-type:text/x-vcard; charset=utf-8; (decoded 7bit)
>-----Original Message-----
>From: RemoveMEpiclist-bouncesTakeThisOuTmit.edu [piclist-bouncesEraseME.....mit.edu]
>Sent: 24 May 2006 19:25
>To: Microcontroller discussion list - Public.
>Subject: Re: [PIC] WiFi & PIC
>
>
>This is not possible.
>Wifi is 2.4 GHz
>Pic is less than 100MHz
>Therefore, you cannot implement a wifi device with a pic.
2.4GHz is simply the RF carrier frequency which has nothing to do with the clock rate of a PIC. The OP simply wants (or doesn't, as the case may be!) to be able to control a WiFi device with a PIC, not build one from scratch with a PIC generating the RF.
Regards
Mike
=======================================================================
This e-mail is intended for the person it is addressed to only. The
information contained in it may be confidential and/or protected by
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not make any use of this information, or copy or show it to any
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=======================================================================
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.
******************************************************************
Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC
consultant in 2004 program year. http://www.embedinc.com/products
Mike Harrison wrote:
> Wifi would probably overkill for this - a more appropriate way may be
> low cost sensor/transmitters on one of the unlicensed UHF bands sending
> short packets every few minutes to one or more receivers, depending on
> distance - the receiver could either be a PC or a data concentrator
> that bulks up the data to send via wifi/GSM/GPRS etc.
That's actually what our WiFi gizmo is a receiver for. Normally the
receivers are connected to wired ethernet, but they want to have a WiFi
option. The real job of the gizmo is to receive periodic transmissions from
up to a few 100 little transmitters scattered about. These use 434MHz in
the ISM band, and run for well over a year on two button cells. The
existing full featured tags have a 16F630 in them, and the new single-use
version they just came out with has a 10F202 controlling it, so you can see
it's not that complicated.
******************************************************************
Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC
consultant in 2004 program year. http://www.embedinc.com/products
alan smith wrote:
>> How about using cheap unlicensed transceivers in the sensors that talk
>> to a wifi equiped base-station? This could be an embedded PC to
>> simplify code development and gives the wireless web browser access
>> that he wants.
>
> That is exactly the approach I want to use.
That is the approach we are using, except that a PC is not needed. We are
using a 30F3010 to interpret the analog data from two RF receivers, and a
18F6527 to handle external communications, which can be RS-232, wired
ethernet, or WiFi.
******************************************************************
Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC
consultant in 2004 program year. http://www.embedinc.com/products
OK...I wasnt sure if you were doing a chip level solution, or off the shelf (latter obviously and easier).
Olin Lathrop <EraseMEolin_piclistembedinc.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.
******************************************************************
Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC
consultant in 2004 program year. http://www.embedinc.com/products
>
> This is not possible.
> Wifi is 2.4 GHz
> Pic is less than 100MHz
> Therefore, you cannot implement a wifi device with a pic.
>
Not to be too cruel, but ROFL...
2.4GHz is the carrier frequency, not the data rate.
On Wed, 2006-05-24 at 10:37 -0700, Bob Axtell wrote:
> In general, I am not enthused about PC wireless schemes. I and some
> associates looked into these for a police data dump station, and
> the results were NOT heartwarming; not one method was free from hacking.
> Personally, I think that IEEE803 etc was a plot hatched by
> the NSA/IRS/FBI cabal to easily read everybody's computers by simply
> parking in the front driveway and hacking in. It is INCREDIBLY
> easy to hack.
True, but it's also incredibly easy to make very secure. Buy the right
router and wrap VPN around the wireless connection (all the software
support is in Windows), as secure as you'd like.
On Wed, 2006-05-24 at 13:56 -0400, Charles Craft wrote:
> A google search on "802.11b transceiver" shows lots of chip sets.
> You might find a demo board in there that fits your needs.
>
> Or if you go with an off the shelf solution, what about a USB 802.11b adapter instead of the PCMCIA cards?
Generally PC WiFi adapters, be they USB, PCMCIA or PCI, are very "dumb",
and offload a MAJOR portion of work on the PC's driver.
There are exceptions of course, and aiming for adapters that are used on
less powerful devices (i.e. CF or SD WiFi cards meant for PDAs) can
drastically reduce the software support.
Another option, although too big for the op, is WiFi routers. They are
so cheap today I often see them on sale for $10. Some of them have
wireless client capability, meaning they basically act as an Ethernet to
wireless bridge, connecting to a normal access point. I've got one at
home that works very well.
Herbert Graf wrote:
> On Wed, 2006-05-24 at 10:37 -0700, Bob Axtell wrote:
>
>> In general, I am not enthused about PC wireless schemes. I and some
>> associates looked into these for a police data dump station, and
>> the results were NOT heartwarming; not one method was free from hacking.
>> Personally, I think that IEEE803 etc was a plot hatched by
>> the NSA/IRS/FBI cabal to easily read everybody's computers by simply
>> parking in the front driveway and hacking in. It is INCREDIBLY
>> easy to hack.
>>
>
> True, but it's also incredibly easy to make very secure. Buy the right
> router and wrap VPN around the wireless connection (all the software
> support is in Windows), as secure as you'd like.
>
> TTYL
>
>
I agree. But police employees are not capable of doing that with any
degree of reliability.
The possible consequences far outway the possibility of immeasurable
damage. Imagine
reporters having complete access to secret surveillance image files
through hacking. Boggles
the mind.
Don't get me wrong, I love gadgets. But unforeseen things go wrong....
constantly.
On Wed, 2006-05-24 at 14:42 -0700, Bob Axtell wrote:
> I agree. But police employees are not capable of doing that with any
> degree of reliability.
Of course they can. VPN is VERY popular these days, presenting a login
screen is something ANY computer user is used to.
Of course, their IT department needs to set up the computer, but that's
done anyways.
> The possible consequences far outway the possibility of immeasurable
> damage. Imagine
> reporters having complete access to secret surveillance image files
> through hacking. Boggles
> the mind.
Since it's clearly a very illegal activity it's unlikely any respectable
news organization would do something like that much.
That said, wrapping a VPN around the connection would pretty much
eliminate that problem.
Ignoring all this, that sort of information has been stolen for decades
through other means, adding wireless to the mix wouldn't have much
effect.
Herbert Graf wrote:
> On Wed, 2006-05-24 at 14:42 -0700, Bob Axtell wrote:
>
>> I agree. But police employees are not capable of doing that with any
>> degree of reliability.
>>
>
> Of course they can. VPN is VERY popular these days, presenting a login
> screen is something ANY computer user is used to.
>
> Of course, their IT department needs to set up the computer, but that's
> done anyways.
>
Yes, they CAN do it. Apparently you have never worked with a government
agency before. Believe
me, Murphy was overly optimistic. {Quote hidden}
>
>> The possible consequences far outway the possibility of immeasurable
>> damage. Imagine
>> reporters having complete access to secret surveillance image files
>> through hacking. Boggles
>> the mind.
>>
>
> Since it's clearly a very illegal activity it's unlikely any respectable
> news organization would do something like that much.
>
Of course its illegal. But here in the states- these days- reporters win
Pulitzer prizes for exposing the
nation's highest secrets, and nobody in the liberal media goes to jail.
Its a different world. Surreal,
strange. Trust me, they would take it and run with it.
The Constitution says "legal tender will be gold and silver coin". It
has never been repealed,
yet not one penny of US currency is backed by gold or silver in any
form, coin or bullion.
> That said, wrapping a VPN around the connection would pretty much
> eliminate that problem.
>
> Ignoring all this, that sort of information has been stolen for decades
> through other means, adding wireless to the mix wouldn't have much
> effect.
>
Yes, and there is almost always a trail. Stealing wireless signals at
the source leaves no trail
whatever.
mit.edu [.....piclist-bouncesKILLspam
