Common XBee Mistakes

Your XBee project isn’t working? Here’s some common mistakes that both beginners and experts make:

  • Not using the latest firmware (especially if ATD0 or ATIR is giving an error)*
  • No reference voltage to VREF pin on the 802.15.4 radios (analog and digital reads give wrong values)
  • Forgetting that AT commands use hexadecimals
  • Hitting return after +++ (or otherwise not respecting 1 second default guard time)
  • Conversely, _not_ hitting return after an AT command
  • Letting the XBee time out of command mode before issuing an AT command (you’ll know because you get no response)
  • Forgetting to write the configuration to firmware with ATWR (unless your application configures the radio interactively)
  • Not using ATRE (restore factory defaults) before re-configuring a previously used radio (previous settings lurk unless you manually reset them all)
  • Looking for analog output on the analog input pins instead of pins 6 and 7 (P0, P1)
  • Using a voltage regulator without decoupling capacitors (10uF on input, 1uF on output is good)
  • Mixing up TX and RX pins (fastest way to check this is switch the wires and see if it starts working)
  • Using ZigBee version (ZB Pro or ZNet 2.5) when 802.15.4 version would do just fine (if you don’t need to make a mesh network)
  • Trying to read more than 1.2 Volts on the ZB Pro and ZNet 2.5 analog inputs (that’s the limit)
  • Buying Pro radios when you don’t need them. (Cost more, bigger, use a lot more battery)
  • Deciding the XBees are flaky. (You may not be using them correctly, but they are very reliable)
  • Deciding an XBee is burned out when it’s set to a different baud rate (check ON and ASSC lights)
  • Deciding an XBee is burned out when it is just sleeping (Check ON light to see if it blinks occasionally)
  • Forgetting to supply power or ground (ON light may go on and ASSC light may blink but both will be significantly dimmer)
  • Not contacting Digi sooner for support, especially if your radio seems dead or you keep getting an error you don’t understand.

XBee Arduino Mistakes

  • Sending continuously without any delay (try 10ms delay)
  • Not removing RX and TX connections before uploading code (Arduino will give an error)
  • Not removing RX connection when reseting, if you are continuously receiving data. (Arduino will never reset)

XBee LilyPad Mistakes

  • Hooking up more than 4 Volts to the 3.3V pin
  • Using switches without pull-down resistors (but not if you use the internal pull-ups)
  • Not using a pull-up or pull-down resistor on pins 5 and 7 (these don’t have internal pull-ups at all)
  • Using sensors without voltage divider resistors (if your sensor needs that circuit)
  • Using too-resistive conductive thread for power and ground (try fabric or wires)
* X-CTU is required for firmware upgrades

This list isn’t exhaustive. Got a suggestion I should add? Let me know!

185 Comments on “Common XBee Mistakes

  1. Good list!

    Did most of these things wrong at one point in time but figured it out. A few things on this list i didn’t figure out yet, so you saved me a lot of time!

  2. Just got in 2 Xbee pro’s . When I send it any comms all I get back is .XYz. This happens to both Xbee’s .Any thoughts?

    Butch

  3. I had them associating one minute, with successful ATND, and then they just quit. No harware changes, nothing. SOMETHING is flakey ….

    • This will work. It’s probably out of official spec on both ends so more appropriate for a quick prototype rather than for a manufactured device.

  4. Hi,

    one of my xbee modules does not connect anymore. I use a XBee Explorer Regulated and an XB24-BWIT-004. If i connect the module to Power the Dout LED ist always on. it does not connect to coolterm or X-CTU
    any chance to get the Module alive again?

  5. Hi,
    I am using an XBee module to send hexadecimal values oF characters from my pc to a chracter lcd interfaced to another XBee.The communication between the two modules is established but the lcd displays characters not corresponding to the hex sent.I tried changing the baud rate and introducing delays in my code didn’t work.wat should I do?

  6. Hey, I have a problem about below scenario, I need some help as I am not studying in electronic engineering. I’m just a hobbyist.

    I used Arduino Uno A0 as analog output and directly connected to Xbee Series2 AD0 as analog input. Then I implemented (FOR) loop on the Arduino to analog.Write the value. Nevertheless, the data I read from xbee were unpredictable and most of them were zero.

    The problem I think that I should put a resistor or capacitor between them. Am I right? If yes, what resistor or capacitor I should put, I mean how much ohm or uf ? And How I link them, I mean the positive leg should go which where ?

    Thank you…

  7. Can Zigbee Coordinator send data to Zigbee Router ?
    The program as below was uploaded on Arduino that the Tx connected to the Xbee Coordinator’s Din .
    if (triggered)
    Serial.print(“1”);
    else
    Serial.print(“0”);

    Nevertheless, I was able to see the Din on Zigbee Coordinator was blinking, but the problem is I could get any data at Zigbee Router’s Dout and the Dout on Zigbee Router was not blinking. So may I know whether Zigbee Coordinator can send data to Zigbee Router ?

    • Hey, I’m a student at Thomas More in Belgium. For my internship I’m building a Wireless sensor mesh network. I was using your book to get started with the XBees and it really helped allot, thanks! The thing is, I ran in to the same problem as Timmy.

      Is it possible to send data from my Coordinator to my routers?

      I have the following setup:
      XBee coordinator on a explorer board connected to the PC, from X-CTU or another terminal i want to send simple data like ‘7E A1 B2 C3’ to test if everything is working. I have 2 Routers connected to an arduino with the XBee shield. All i want is to do ‘if (Serial.available() > 0) ‘. And i’m gonna print something useless to check if it’s working.

      It’s probitly something wrong in the firmware settings of the coordinator I guess?

      Any help would be appriciated!

      • Sure, to send from Coordinator to Router radios, check the Simple Actuation Example in the book. There’s more than one way to accomplish this, but for a small network that example may be simplest.

  8. Hi,

    I have a question about XBee modules .. If I have two XBee modules one of them is connected to the laptop. can I from the laptop change the pin setting (Ex. make pin D0 output High & low) of the other XBee that is not connected to the laptop ??

    • Yes, you can use Remote AT Commands in API mode to accomplish this. See Chapter 5 of my book for more information, and Chapter 6 for a project that implements the function.

  9. Hello

    My Xbee shield’s led is always on when I power the arduino board for 10 seconds and then turns off, resetting as well my arduino(I have checked reset, is at 0v, constantly). It seems that sleeps too early and I cannot even send any data or be able to configure the Xbee. Is this the issue or my Xbee is dead?
    How I can overcome this problem?

  10. I’m recently having a number of problems, though I’m not at all certain that they are Arduino problems.

    #1 When I have two Xbees running the range test on two different machines I get a LOT of errors even though the signal strength looks fine (-40 or -44 I think). Am I only supposed to be running on one and putting the other in loopback? I’d swear testing like this worked before, though I’m in a more electrically noisy environment.

    #2 I’m doing a really simple test with my Arduino-driven Xbee and a modem connected to X-CTU. It’s pretty much a loopback test. The Arduino serial monitor shows that all packets sent from the modem are getting the correct response, but only some of them are making it back to the X-CTU terminal. Same problem happens if I switch the chips. At present I’m connecting the Din of the XBee to TX of the Arduino. I’m seeing that the XBee shield and another circuit I found on-line include a bit more stuff (10K and 15K Ohm resister or 1K and a diode). Is that my problem? I’m only using pins 1,2,3,4 on the XBee.

    3. Finally (and on a more trivial note) X-CTU keeps insisting on opening a window called “update summary” every minute or so. It started doing this after I did an update. It’s not horrible (if I leave it open it doesn’t open a new one). Anyone seen this?

    • #1 Only one should be in loopback. Otherwise you’ve created an infinite loop.
      #2 Hard to say without seeing all your code and wiring so this is just a guess: The Arduino can’t send infinitely fast to your XBee. Sometimes a little 10ms delay in your Arduino code can make all the difference. That or upping your local serial port speed on the Arduino/XBee connection might help as well.
      #3 I’ve seen this too on the latest verison of X-CTU and tacitly used the same solution. Will ask about it at Digi, but it feels like a minor bug rather than anything we’re doing wrong. If so I’m sure the next update will clear it up.

      • #1Actually, my question is can I have _both_ in range test? It seems to get wonky and claim things aren’t working even though I’m fairly sure I’m seeing the data correctly when I change to terminal.

        #2 THANKS! a 5ms delay was enough to get communication to be reliable.

        #3 Thanks for the reality check.

        Now I just need a clean way to debrick a bunch of Xbees that are in a weird mode (115200 baud at least which I’m told my PC can’t quite match as the Xbee bauds are off at those speeds). I wish there was just a pin you could set high or something which would cause a chip to go back to it’s factory defaults…

        Ah well, onwards. Again, thanks so much.

  11. hi faludi,
    here i have a pair of xbees configured in analog mode and sending data serially in api form, can u be olease be kind enough to tell us how can i deforrm the api using c and not the java apis??
    thanx in advance

  12. Please i need your help
    i have XBIB-U-DEV and XBIB-R-DEV kits
    and i want to know how i can read the value of the pin if i make it input like DI8
    i use command ATD8 3 to make the pin as input
    how i can read the value of the pin ??if i press button and release it how i can read this action

    waiting for your reply
    Ahmed

    • You’ll probably want to read it using API mode on the receiving XBee, either by writing your own code or using a library for the program that you’re sending information to. Chapters 4 and 5 of my book cover this pretty thoroughly for the Series 2 XBee. The Digi Product Manual also has useful documentation, and the iDigi cloud service might be of use if you are going to generate a bunch of data.

  13. hi i keep getting this message: “Error reading com port” when i plug in my xbee through my ardupilot mega 2560 and ground based xbee. both are connected to laptop via usb. i am trying to get a range test for the xbees and the terminal. baud rate is set to 57600. what seems to be the problem?

  14. I have two XB24 modules with Sparkfun USB interfaces. They both were working fine with one unit periodically transmitting the state of a digital I/O pin to the other. Then I enabled cyclic sleep mode (SM=4) on the transmitting unit to see if I could reduce the power draw. BIG mistake! That unit is now happily transmitting, but will no longer accept any commands.

    How do I get this unit to respond? I’ve tried all sorts of ways to talk to it over the USART as well as a remote device – all to no avail. I would be happy to just reflash it if only I could get it to pay attention!

    Any suggestions will be greatly appreciated!

  15. I’ve got two Xbee S2 modems here, got them talking to each other so far, following stuff in your book, got a LM335 connected to pin1 of the sensor node with D0=1, IR=03E8, DH=0, DL=0.

    The only message the sensor node (Router AT or API mode) sends is 0x91, it never sends the 0x92 message with the samples in it. It does, however, send the 0x91 according to the schedule it should be sending 0x92 messages…

    I’m mostly using the Python library, but I’m observing this in the terminal of X-CTU as well, with the coordinator connected to the computer.

    Latest firmwares, tried two different Xbees as the sensor node. Any idea what I missed?

    • 0x91 is the frame type for information sent with explicit ZigBee addressing, so that’s almost certainly something you don’t need. If you are in AT mode, I’d reset the unit with ATRE, then configure it again. In API mode you can reset the unit with X-CTU and configure it again in the same way.

  16. Help!. I have 4 XBEE’s. I can’t get any of them to work : (

    I have this shield: http://iteadstudio.com/store/index.php?main_page=product_info&cPath=18&products_id=348.

    I’ve tried it with Arduino chip in and looping or w chip out, but I can’t establish *any* serial comm via USB at any baud! I tried my Mac and a PC, Coolterm and x-CTU. Nothing’s working and Im pulling my hair out. I type +++ and nothing happens. Everything is hooked up correctly…I even tried soldering right to the XBEE and bypassing the shield.

    Obviously Im doing something wrong cause 4 XBEEs can’t all be bad. I’d appreciate ANY help or ideas!!! Thanks!!!

  17. Hi Rob,

    Thanks for a very clear step-by-step tutorial on set up Xbee in BSNW. I’m now stuck with chapter 3: Build a better door bell. I’m using 2 Xbee S2 modules and 2 Arduino Duemilanove328 boards. The problem is that the Router modem (Bell system connected to a laptop) keeps receiving number 53. This happens all the time without the button on the Button system being pressed.

    I wonder if someone has come across the same problem?

    Thanks

  18. Hi all,

    I am attempting to complete a range test, however every time I type in atci12 it returns “ERROR”. Any ideas?

    I have one xBee plugged into my laptop through the explorer, and the other xBee is plugged into an arduino/wireless SD shield. Both are connected to my laptop via usb. I tried resetting both my xBee’s to the factory settings, and I also tried to reset the arduino and the sd shield with the little brown reset buttons. Can’t seem to get them working.

    Steps I followed to get to the atci12 command:

    +++ (computer gives OK)
    atnd (hit return)

    (computer returns)
    0
    13A200
    407E0F28
    1B

    +++ (computer gives OK)
    atci12 (hit return)
    ERROR (computer response)

    Thanks! 🙂

  19. i have xbee and connect it with minimum connection
    VCC GND RT XT
    when i received from XBee connected to arduino to Xbee connected to PC it writes on terminal unexpected char how i can remove it ?

  20. Dear Faludi,

    I am using Serial Comms link to communicate between my arduino and pc. All is well till I introduce the XBEE modules on either side of the link. I have checked the BAUD rate. It is globally 9600. I have seen that looping the TX and RX of the XBEE returns the same value implying that communication is reliable. In fact, if I give serial data via the USB cable while the XBEE is connected to the arduino, the other end seems to be receiving data on a hyperterminal. But, full duplex communication seem to be failing when both ends are communicating with each other together. Help appreciated.

    Thanks
    Suraj.

    • Check that your TX and RX are hooked up properly. If you are seeing received data when the XBee is attached to the Arduino (via the Arduino’s FTDI UART) then they’re probably backwards.

  21. Hey, i wonder if anyone can help me.

    Im trying to get one XBee to read an analog voltage, limited to 1V, and transmit this to another XBee which will push this data out its URAT pin 2.
    Using the interface board from digi and the X-CTU software, i can confirm that they are communicating with each other. However when i try the XBee’s in my very basic circuit, they do not read and then transmit the voltage or any data.
    The circuit is a 3.3V regulator with 10uF and 2uF capacitors on the input/output respectively and a potential divider providing 1V to AD1, which is configured as a ADC. Vref is tied to Vcc so is at 3.3V, all other settings are default.
    The sensor XBee has the function set ‘End Device AT’ and the receiver as a ‘Coordinator AT’. Am i missing something critical? or is it impossible to do what i am trying to do…

  22. Hi !

    I have a problem on a xbee send in API. I get a temperature sensor (LM35DZ) on pin 19 (Analog input)
    In reception i have this :

    7E 00 0A 83 56 78 32 00 01 02 00 03 FF 77

    I try to recup the temperature with an arduino but the byte 11 et 12 don’t change when i heat the sensor why?
    03 FF it’s 1024 reference voltage? i don’t see the problem.

  23. ello sir,
    I kindly request your urgent help, please aid me out

    am using this product :
    http://www.google.com/products/catalog? … CFkQ8wIwAA

    where i have my xbee shield , xbee explorer to connect my xbee modules directly on, i programmed the arduino w/o the xbee on, and configured them both on default configuration (as i live in very distanced place where no one can interfere with my xbees talks), placed them togather and used the X-CTU program terminal tab to send a or b to turn a LED on and off respectively ,
    but nothing happened?

    note that am using series 1 from that kit above, with arduino uno and
    Modem : XB24 – function set : Xbee 802.15.4 , version 10ED,
    i connected them both to a power supply and the LED did blink as test to make sure it works fine

    DIO5 on the shield blinking all time, when i send something the RSSI emit light for a while then goes off,

    help plz i need to submit this work asap

      • i used this code on my arduino:
        …………………………………
        void setup() {
        Serial.begin(9600); //initialize serial
        pinMode(13, OUTPUT); //set pin 13 as output
        }

        void loop() {
        while(Serial.available()){ //is there anything to read?
        char getData = Serial.read(); //if yes, read it

        if(getData == ‘a’){
        digitalWrite(13, HIGH);
        }else if(getData == ‘b’){
        digitalWrite(13, LOW);
        }
        }
        …………………………
        i tried to send also just a B and receive it on my terminal tab on the X-ctu, but aint receiving anything

  24. Hi Rob,

    Firstly, thanks for writing the wireless sensor networks book, it has been extremely helpful over the last few months!

    I’ve built a sensor network based upon the one in the book and I’m using it to monitor heart rate and breathing movements from two wirless sensor straps – more details here http://you-rhythmic.com/?page_id=57.

    I’ve been having some problems with speed when both sensor straps are connected and was wondering what setup you would recommend in order to achieve maximum speed? I have set the baud rate to 57600 on both the end devices and coordinator and this appears to have helped somewhat, but I think it could still be faster.

    Any suggestions would be gratefully received!

    Thanks,

    Evan

  25. Hi, I have a pair XB24s running just fine but its not flashing the RSSI heartbeat LED like my other series 2 Xbees do – RSSI LED is connected to Xbee pin 6 – any ideas what I am doing wrong?

      • Thanks for getting back to me faludi. I’m not sure what I mean 🙂 On the Xbee shield there is an LED marked RSSI, on my series 2 Xbees this blinks to show its active…. for some reason my XB24s don’t blink this same LED… very useful when testing putting Xbees to sleep 🙂 I’m guessing I need to change something in the XCTU config but not a clue what?

  26. I have two XBee’s and two Arduino UNO Rev 3’s. Separately they function OK. When I send “X” and “0” s from coordinator to router to blink Pin 13 light when “X” is received at router arduino I can detect “X” and “0” at router XBee’s XMit line but Arduino does not blink Pin 13 light. I have XBee and Arduino power, common, xmit & rec line connected and switched xmit and rec just in case I had wrong. What am I doing wrong. Thank’s a million!

  27. Please can you assist? I have read many books which show the used of LEDs for displaying the status of the XBee device but none use a series resistor for the LED.

    Do you not need to use a resistor?

    • The XBee will limit the current but for good form you can still use a resistor. Moe important for a finished design than for prototyping purposes…

  28. Could you offer me assistance. For the indication LEDs for association etc. what is he nominal output voltage 3.3v? And should a series resistor be used with each LED? As with the sensor networks book, I have used no resistors and everything works fine, but I am writing a project and want it official. Does the XBee include resistance so that LEDs can just be attached stand alone?

    Any help would be hugely appreciated!

    James

      • I recently made the mistake of connecting PWM0 to base of NPN transistor, and NPN-base directly to ground (I had 12v driving a motor, motor low-V connected to NPN-collector. The XBee burned out.

        Should that have happened, based on “The XBee microcontroller limits current” statement you make?

      • (stupid fatfingered the post. Ignore. here’s what I meant to say:
        I recently made the mistake of connecting PWM0 to base of NPN transistor, and NPN->>emitter<< directly to ground (I had 12v driving a motor, motor low-V connected to NPN-collector. The XBee burned out.

        Should that have happened, based on “The XBee microcontroller limits current” statement you make?

        • I’m wondering if you accidentally routed 12V directly to the radio. Your description doesn’t indicate that, but it’s pretty easy to get transistor pins confused and possibly that could have happened. Otherwise no, a properly oriented transistor will not route power to the XBee, so in general this kind of thing is safe to do.

          Anytime there’s higher voltage in your circuit, it’s an excellent idea to go over everything with a multimeter before plugging in your XBee to make sure a mistake hasn’t cropped up. I’ve made my own share of flubs and it gradually taught me that anything I’ve just wired up is guilty until proven innocent.

  29. I am having difficulty with working with two XBees Series 1 with only one microcontroller at the base. I have a Seeedstudio Grove XBee Carrier with the XBee and an analog Sharp sensor attached. I would like to send the data from the sensor to the other XBee which is on an Arduino Mega. I am using CoolTerm and right now I have this code:

    Remote (Carrier/Sensor)
    ATDL 2345
    ATMY 7890
    ATBD 3
    ATD5 2 //have the analog input of the sensor on pin 15/D5
    ATIR 14
    ATIT 5
    ATIC 1
    ATAP 2
    ATCE 0

    Base (Arduino Mega)
    ATDL 7890
    ATMY 2345
    ATBD 3
    ATP0 2 //Not sure about how to read the incoming data
    ATIU 1
    ATIA 7890
    ATIC 1
    ATCE 1

    I have read that I should be in API mode, but I am not one hundred percent sure. I am new to this, and any help would be greatly appreciated.

  30. Sir,
    I am building my own xbee Explorer serial . but it is not working. when i connect serial port to pc , no connection is established. SO kindly tell me how to check my board , that it is working properly or not?
    Waiting for your reply..

  31. I have two X bee S2 module .I have used SM4 for send X bee module in sleep mode.But problem is that now X bee module is not return in awake mode it is not transmitting any value and unable to Read module.

  32. Hello Robert. I might be making a ‘common XBee mistake’, perhaps you can enlighten me. One scenario you don’t deal with in your excellent book “Wireless Sensor Networks”, is that of end-points sleeping. I envisage a number of endpoint series 2 modules which cyclic sleep, and on waking transmit pin values to a controller. I haven’t read anywhere how to do this, or whether it is possible. I tried some sleep scenarios, and the endpoint might poll the controller, but the attached PC doesn’t see anything on its serial connection. So as I understand it, the controller has to have a fetch message queued for every endpoint, refreshed for every sleep period. This seems very clumsy and inefficient to me.
    So can I have an endpoint XBee just wake up and transmit without being polled?

    • End devices sleep by definition, and can do so cyclically with a transmit after each sleep period. Have you checked the information in Chapter 6 on sleep mode, and the example about sleeping?

  33. Perhaps I should enlarge on the previous entry. You did deal with endpoints, but not where one would automatically send data, like an always-on device can do periodically.
    -And I have my controller in API mode, the end device in AT mode.

    • Sending should still work fine. The XBee sends a frame of data on wakeup, then as many more frames of data as will fit in the sleep timeout window. But always one on wakeup, no matter what the other settings are.

  34. Hello. This seems to be a good place to post a question about an issue I’m dealing with.
    Short story:

    Tx is sending some text, it could be ‘X’, ‘C’, ‘T’ or ‘S’.
    Rx is receiving ‘244’ (whatever letter is sent).

    I have checked both via Serial monitor. Tx is cool. Rx is getting just the numbers.
    I’m using 10ms delay
    both are 57600 baud

    I only can think about the Baud Rate, but I’m not sure. Anyway I need the first arduino to be at 57600.

    Any ideas?

  35. Faludi – Awesome book, has helped me tremendously.
    But…i have a problem, I am using API1 mode and send from xbee connected to PC with X-CTU the packet

    7E 00 12 10 01 00 13 A2 00 40 9A 1B 93 FF FE 00 00 56 00 26 00 38

    Which sends the reset command to my LinkSprite serial camera expecting a reply of 76 00 26 00 but all i get is the successful send response of

    7E 00 07 8B 01 FF FE 01 00 02 73

    I see this response almost immediately while the remote xbee appears to still be sending data/LED blinking as if there is data being sent to the xbee connected to the PC but no data showing up on screen X-CTU. Is this data waiting in a buffer i need to read on the PC connected xbee?

    Any words of wisdom would be fantastic.
    Thank you

    • I forgot to mention that in transparent mode i can use the Linksprite software – LSY201 – to connect to the camera across Xbees and retrieve an image so the connection works, just the API mode is giving me fits.

      Thanks,
      Jason

    • Sorry don’t know much about the LinkSprite. The XBee’s buffers will flush out automatically, so it’s unlikely that any data is waiting for you unseen.

  36. i am getting negative values when i transmit values from 0-9 to the receiving xbee. like this :
    6
    -35
    -38
    6

    6 is the correct value but how did these error negative values come.

    • The XBee is doing its job perfectly. It looks like you’re transmitting a carriage return and a line feed after the numeral, then you or your software are using the 48-n trick to change from ASCII values to real numbers.

      Carriage return is ASCII 13 so 13 – 48 = -35 and linefeed is ASCII 10 so 10 – 48 = -38. Either fix this in the sender or receiver software and you’re set.

  37. Hi,

    I have 2 Xbee S2B pros…one is set as a coordinator and the other is set as a router. When I send 1 byte of data from the coordinator to the router, it seems like there is long lag before the two are connected for the first time…Do you know what might be causing this?

    Thanks!

    Siddharth

  38. Hi…I have two xbees S2…one is in coordinator API mode, 2nd one is in end device AT mode. I have succesfully interfaced them together.I send rf data from API coordinator using frame ID 0x10 .In the receiving end i receive only the rf data cuz receiver is in AT mode. But after sending about 9 packets with significant delays my xbee AT receiver stops receiving rf data for about 3 secs.After that it starts receiving data for another 9 times. How to remove this problem?? and continuosly receive data. Will resetting xbee after each received packet work???? plzzz help!!

  39. Hi,

    I have a Xbee Wifi, which works fine in terminal mode with my server on a pc. i’m trying to get an analog sensor to send data to the same, running in transparent mode, VREF setting is 0-1.25V, sample rate is A, and DIO3 is set to analog. I’m expecting that there is a periodic write to my server with whatever I put over the DIO3 pin (even if there is nothing attached to it), but nothing happens. I’ve tried with the actual sensor connected, which ranges from 0V-1.26V and that also doesnt work. How do I debug an issue like that? Thank you very very much.

  40. Hi
    I have two xbees S2B…one is in coordinator API mode, 2nd one is in Router API mode.
    I want to send a specific packet (like 11 22 33 44 55 66 )with coordinator and recieve it with router. what is the API command format?
    Can you help me with this issue, please.
    Thanks a lot.

  41. Hi, I have the “Building Wireless Sensor Networks” book and have built the Simple Sensor Network on p142 but i cannot get it working. Having exhausted all other options I thought i’d ask here. I am successfully sending and receiving data into Processing (the thermometer appears when i switch the router on) and a value appears which is incorrect – “analog value: 0 temp: -273?C”. If i take out the hookup wire connected to AD0 i do get a varying reading so i know the program is accepting the signal. Could you assist as to what the issue may be? I haven’t modified the supplied code in any way and have all thge API libraries installed. Many Thanks

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