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All things pertaining to wireless and RF links
By andyf97
#44932
I have 2 xbee pro wireless modems series 1 with level convertion to connect them to a pc each via comports, data is flowing lovely at last after a lot of problems.

Its just a few meters between them.

I am using X-CTU in terminal mode to send keypresses from one pc to the other.

Ok, so thats fine and working.

what I do not understand is when i press a single character, lets say an A

i receive on the remote PC terminal window 10 Bytes ~.....*.A.

sometimes the * changes to a different character.

If i press a 1 a lot of that string changes.

I am trying to get just the A to the remote without these extra characters.

The end result is I want to send single characters from one PC to 10 remotes, sometimes to a specific one, sometimes to them all as a group.

Trying to make this as simple as possible with AT commands for now but am sure I will have to go to APi when using more than 1 remote.

Any idea what is going on here?
By stevech
#44936
I've used these extensively in the serial port extension mode that you discuss. Never seen what you have. I'd look at (1) RS232 voltage levels; may be marginal (2) gound connection between XBee and microprocessor (MCU); (3) logic levels and pull-ups if needed on the MCU's I/O port pins that interface to the XBee; Look at what you've done with CTS on the XBee. Sounds like you have the baud rate correct. On the MCU side, be sure your baud rate error is less than 1% for the speed you chose versus the MCU's crystal and your choice of divider constant.

I wrote code to use the AT command API to change the destination address to send data to a given node. Just have to do the timing of the +++ just right. Else using the binary API is a lot of work unless you find code to reuse.
By andyf97
#44941
Well i thouight it was strange too but its very consistent strings, if the baud rate was being upset then its likely the received info would be jumbled.

one of these characters seams to be related to the power signal, if I block the signals a lot, the values change so I think its somehow a packet of information. i did start out with the bees setup in api mode then resorted back to AT.
By andyf97
#44942
Its possible i may have screwed up something in the firmware after having so many inicial problems, i will redo it from factory defaults and see what happens. Just a thought, is it possible to load the wrong firmware or will the x-ctu not allow that? I know i did get a lot more features with the newer firmware.

about this sending to many remotes, am not yet attaching an MCU as i want to test code sent from one PC to several other PCs first.

Is there a forum specific to these devices, it seams there's not such a lot of information or examples around?
By corvette123
#44945
i would double check the baud rates...

obviously they should be the same hahahaha

also do the node scan....

oh and if your terminal software doesnt have a hex mode then you can use a serial port sniffer program!!

if you are using DIGI's terminal program then just switch to hex to see whats really happeneing.


and make sure both are AT mode or borth are API mode firmwares...

you said you flashed the firmware yourself with your own hardware.. are you sure you didnt brick it?>

it is easy to brick xbee modules this way.

i have

:D :D :D :D :D :D
By corvette123
#44946
Digi has a forum now i think...

yah thats true not many examples... but its not brain surgery either :)

if you are using your own UNTESTED hardare, 1st i would get the setup right on known DIGI hardware.

then switch the modules to your own hardware.

set up small tests to get a baseline to get things working good. then make small changes at a time until it is right lol
Last edited by corvette123 on Tue Mar 18, 2008 4:39 pm, edited 1 time in total.
By andyf97
#44947
Corvette123,

Your perfectly correct but when I tried to order evauluation kits they said 4 weeks to get it and i am very impatient.

I am quite familiar with most of the subject of interfacing and design, this xbee is the only new part to learn.

I did do a lot of rs485 multidrop stuff in the past and almost trying to replicate to a similar wireless system.

I did also send requests to digi but didnt get any answers so cracked on trying to solve this myself and man its proving to be a headache. I wonder if i will solve it before the 4 weeks digi quoted :)

so, i will keep trying and hope to crack it eventually
By corvette123
#44953
you can get the digi interface boards for about 50 a peice from www.digikey.com

they also sell the xbee modules too.

no waiting!!

probably have the started kits too.


digikey has everything u need in life.

hahahah

:D :D
By andyf97
#44977
well just for other people, i set all the network stuff to zero on both nodes duplicated every setting to be the same and wala, two way perfect comms.

i guess now i can start to move forward.
By corvette123
#45048
glad you got it working!!!

setting DL and DH both to zero on BOTH???


hmmmm


:roll: :roll:
By andyf97
#45049
yes,

Not only just both, setup 4 now and have them all chatting away niceley like this.

Remote to a specific remote
remote to all remotes
remote to base
base to specific remote
base to all remotes
By corvette123
#45095
hahahah well thats a cool trick :)

not in the manual...

whats next??
By corvette123
#45096
another undocumented trick.

there is a software entry point for xbee module bootloaders :)

its an AT command.


how to find it?

use a com port sniffer to watch a firmware update.

and youll see the command!!

no DTR line needed...!!
By andyf97
#45097
next?

Testing, started yesterday doing loopback tests with a remote that was about 300 meters away and with some onsticles in the way, had a good signal and stable responces.


writing code for the MCU's

everything is on several prototype boards, need to have some intermediat PCB's made to bring all the components together.

I hear there are some PC producers that can do fast short volumes online, recommend any?
By andyf97
#45099
corvette123 wrote:another undocumented trick.

there is a software entry point for xbee module bootloaders :)

its an AT command.


how to find it?

use a com port sniffer to watch a firmware update.

and youll see the command!!

no DTR line needed...!!
Nice.

I am starting to find many things that are not documented, when I get some time i will start to make a list and upload it.