Basic Stamp 2 and RF question ( Maxstream)

Joe · 2006-12-29 19:32

Hi,

I need to send AT commands to the Basic Stamp becuase
i will use a Maxstream module.

Where can I learn about Basic Stamps AT commands and examples?

Thanks, Joe

Bruce Bates · 2006-12-29 20:14

Joe -

If you're speaking of the AT (Hayes modem) type tele-communications commands, neither the PBASIC Stamp nor any other microcontroller, nor computer that I know of will recognize them. They are intended to be recognized by a Hayes compatible modem.

Regards,

Bruce Bates

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T Chap · 2006-12-29 20:25

Just curious why you say you will need to send commands to the Maxstream? For basic operation you don't need to tell the Maxstream part anything, or get anything from it other than the serial data going and coming There are other ways to get around sending unique ID's as well if that is what you are after. I use the Xbee Pro's and they are essentially just straight wire.

bennettdan · 2006-12-30 21:47

originator,
··· You say you use the Xbee pro's do they really have close to a mile outside range on the units? I have been thinking of purchasing a set myself.
Joe,
Also the only way to send AT commands from the stamp is with ASCII when I want to dial a number on my cell phone from say a stamp that is bluetooth enable is output ASCII strings that match the AT commands and the phone recognizes it and sends back a AT confirm command that I then use the IF Then command to display a text message on the debug screen.

Is this what you mean? Please tells use more about why and what you need to send AT commands to.

T Chap · 2006-12-30 22:17

The Xbee pro 2.4 gigahertz doesn't have a mile range in my experience, I tested with the onboard chip antenae near a small opening in a sheilded aluminum box, I got around 200 feet outdoors reliable communication. I could have gotten a good bit better range with their small antenae version, not the chip version, but doubtful it would be a mile. They claim 900 mhz is better range that 2.4. They have other units that are suited to longer ranges, even boasting 40 miles line of sight. I didn't require any AT commands on my application, so I didn't explore it but had conversations with their engineers about, it seems pretty straight forward. As far as just simple communication, you don't need any AT commands, the Xbee is just like a straight wire from unit to unit, no setup req'd. Only 3 pins to talk from one unit to the other in one direction. Vdd, Vss, and serial input on one Xbee, serial receive on the other. Your processor can send any ascii data as needed. The baud is fixed at 9600 I think, at least it is the default, I'm not sure it can be changed. I would have to dig into it to know how to do your cell phone idea, but I don't see why you couldn't send the ascii from the processor. The engineers can tell you how to do it in minutes, they were very helpful when I talked with them.

Rich M · 2007-01-02 19:06

I have a zigbee network running with the Maxstream XBee Pro's with the whip antennas, and they easily get to about 3/4 mile - from my aluminum-wrapped cubical, though the walls of my building, and through a small grove of trees. Amazing little devices.

Note that you can run the XBee's in both 802.15.4 mode, as well as Zigbee mode. If you're running in 15.4 mode, then using them as serial port replacements is adequate, but you lose a lot of efficiency when you use the default broadcast mode. Once you get three or more nodes running, then you'd need to start filtering out which datastreams are intended for which devices, and you'd be far better off just using the AT commands to set the destination addresses, anyhow.

Zigbee mode is VERY nice - the mesh networking is absolutely wonderful. And you get to set destination addresses by name, instead of 16-bit address - much more user friendly.

bennettdan · 2007-01-02 19:20

Thanks for the info Rich M I think I will call up digikey and get a couple comming my way to test out I have a clear line of sight at my place so I will see how far they will send data.

Steel · 2007-02-16 20:33

Rich M-

Do you have any block diagrams for setting up networks with the XBee? I have gone through their documentation, and everything is in alphabetical order, instead of process order. I can not find much help online, either.

I am setting up a network with 1 coordinator, and 16 'end users' The coordinator must sniff to see if there are any other coordinators in the area and assume a new PAN(?). It must allow the end users to then 'find it' and associate to it.

Do you know anybody who has had any experiences with this?

Derek · 2007-02-23 02:10

Steel,

when a cooridator is first turned on they do an Active Scan on each channel to locate other coordinators and can have a total of 5 results. Once they locate other coordinates they then pick a channel and PAN ID ( or go to parameter settings) I dont know exactly with xbee 802.15.4 but with Zigbee beta a coordinator can have 20 children, 6 routers and 14 end devices.

Hope this helps,

Derek

Basic Stamp 2 and RF question ( Maxstream)

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