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Topic: XBee 802.15.4 serial com problem (Read 2352 times) previous topic - next topic

utoto

Ciao all,

I have 2 Ard. 328Pro Minis. Each has it own XBee series 1 radio. I am sending and receiving serial data between Ards Tx/Rx pins, but, nada via the same pins with the XBees between.

I have modified configs via X-CTU several times and been all over for info to no avail.

In X-CTU, in the Terminal with jumper from Tx to Rx on the receiver XBee, I can send and receive an ASCII "u" and get it back. Just not with the XBees sending and receiving between the Ards.  =(

Any help is greatly appreciated.

PaulS

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I have modified configs via X-CTU several times and been all over for info to no avail.

Which things have you changed? To what? How are you connecting the XBee to the PC to use X-CTU?

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In X-CTU, in the Terminal with jumper from Tx to Rx on the receiver XBee

With the TX and RX pins hardwired together, the XBee is sitting on the sidelines doing nothing. This was not a useful exercise.
The art of getting good answers lies in asking good questions.

utoto

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Which things have you changed? To what? How are you connecting the XBee to the PC to use X-CTU?


After having played with them for quite a while, I reset both to default XB24 802.15.4 with 10E8 and then set both channels and IDs the same and tried different Baud rates. The Ards were at 9600. So, the XBees were the same then I tried several changes just to get something through.

The XBees are breadboarded to their Ards. But, I take one at a time out and put in on a USB explorer board to my ACER for config.

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With the TX and RX pins hardwired together, the XBee is sitting on the sidelines doing nothing. This was not a useful exercise.


Excuse me. I mean to say the Tx and Rx tied together on the receiving XBee only. So, with the #1 XB hooked to the explorer with X-CTU in Terminal, it sends via the #1 XB to the #2 XB which has its TxRx jumpered. I get back what I send. u = u. t = t. 1 = 1. I did this to make sure of my RF connection, which, I think I have.

Yet the issue still exists that when I send ASCII from the Ard1 via the XBs to the Ard2, I get no actions at all. Now, my code is written so that when Ard2 gets an ASCII char, it will react and also send back an ASCII char to confirm receipt of command. Ard-Ard works correct. Ard-XB-XB-Ard does not.

draythomp

I'm sure you've already tried this, but it should go from arduino tx to xbee rx, out other xbee tx to arduino rx.  That would give you leds on the arduino to look at to see if something got across.  When you're hooked up, look at the leds and see if each of the arduino's leds is showing something.  I did things like holding down a key so I had a long string of characters to show up on the leds.  If you get lights all the way then you may have code or uart problems.  These little guys are sometimes tricky to hook up and you could have gotten a wire mixed up trying different things to make it work.  I know I did several times.

utoto

#4
Mar 15, 2011, 07:33 pm Last Edit: Mar 15, 2011, 07:38 pm by Utoto Reason: 1
Thx 4 the reply.  Yes, I did that with the pins. Still nada.

I almost wonder if the Ards are sending it hex instead of ASCII. But, for how I set it up, it must be ASCII. Or, are the XBs converting it to hex and not changing it back to ASCII when it comes out at either end.  The X-CTU terminal could be showing hex and converting it to ASCII in the terminal I suppose.

AARRRGGHH! Oh, dear. Is that my brain leaking onto the floor again?

__________________________________________________________________________

OK. I tried the XBs alone from a different serial term. All ASCII is coming back ASCII. So, I guess that means the XBs are in good shape. It must be the ARDs Tx/Rx.

draythomp

Did you get the arduino tx, rx lights?  That's the test if it got onto the board.  If you got the lights, well, I may have just run out of ideas.  Could there be some voltage shift thingie going on?   I know I had trouble going from 5v to 3v and so forth for a while, but it doesn't sound like this is your problem.  There is also the possibility that the xbees are starving for voltage when they try to transmit.  That will shut them off sometimes and the period is short so it may not show up on a voltmeter.  If this is the problem you need a capacitor to buffer the supply voltage for them.  Hmm, let's see if I can think of anything else...

I know, try one arduino at a time shorting the far end xbee so it sends back the character.  That could help localize the problem since the arduinos work wire to wire and the xbees work rf to rf.  Try isolating one wire to rf link at a time.  I don't know if this will help, but maybe something will turn up by trying.  If you have rssi leds on the xbees you should see them go on when the character comes in.  If you don't, prowl in your boxes and get one out, they can be hooked directly for the short term and you don't have to search for a resistor as well.  At least the rssi works like that on series 2, I haven't tried series 1 this way.

Heck, you may have to get a voltmeter and look for pulses on the darn arduino digital pins to see where the signal is getting lost.  It's out there somewhere.....isn't it?

utoto

Thx. Actually, with it as Ard-XB-XB-Ard, I can see RSSI's on when XBs com back and forth. When I use button switches from either Ard I see the DOUT and DIN lights on XBs working correctly. This leads me to believe it must be something in the Ards.

So, I tried powering Ard1 and XB1 from one USB port and Ard2 and XB2 from another port. Should be plenty of current. But, still no correct function.

draythomp

You're right, it does sound like something in the arduinos.  Strange how they work with wires though.

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