/ / Introduction

• low power
• addressing
• cheap (sort of)
• wireless
• small
• standardized

LadyAda's breakout board

• Onboard 3.3V regulator to cleanly power your XBee, up to 250mA
  
  
• Level shifting circuitry means that its trivial to connect it to 5V circuitry such as an Arduino without risk of damage
  
  
• Two LEDs, one for activity (RSSI), the other for power (Associate)
  
  
• 10-pin 2mm sockets included to protect the modem and allow easy swapping, upgrading or recycling
  
  
• All the commonly used pins are brought out along the edge, making it easy to breadboard or wire up
  
  
  
• For use with any XBee/Pro pin-compatible module (check your module datasheet to verify power needs)
  
  
• Specifically created for use with an FTDI cable to connect to a computer via USB. This means that you can use, configure or upgrade the adapter painlessly simply by plugging in a cable.
  
  

• 3V pin - this is either an input power pin (if 5V is not provided) or an output from the 250mA regulator if 5V is provided
  
  
• DTR - "Data terminal ready" this is a flow control pin used to tell the XBee that the microcontroller or computer host is ready to communicate.
  
  
• RST - this pin can be used to reset the XBee. By default it is pulled high by the 10K resistor under the module. To reset, pull this pin low.'
  
  
• Ground - common ground for power and signal
  
  
• CTS - "Clear to Send" this is a flow control pin that can be used to determine if there is data in the XBee input buffer ready to be read
  
  
• 5V - this is the power input pin into the 3.3V regulator. Provide up to 6V that will be linearly converted into 3.3V
  
  
• RX - This is the XBee's serial recieve pin. Serial data is sent on this pin into the XBee to be transmitted wirelessly
  
  
• TX - This it the XBee's serial transmit pin. Serial data is sent on this pin out of the XBee, after it has been transmitted wirelessly from another module
  
  
• 0 RTS - "Ready to Send" this is a flow control pin that can be used to tell the XBee to signal that the computer or microcontroller needs a break from reading serial data.
  
  
• see pin #1
  
  

AT commands

AT->OK
ATMY ->my address
ATDH.ATDL ->destination address hi/of-destination of 
ATID->personal area network ID
ATCN->end command mode
ATD0..D8->set pins
	ATDX0-disabled
	ATDX1-undefied
	ATDX2-analog input
	ATDX3-digital input
	ATDX4-digital output low
	ATDX5-digital output high
ATIR->sets sample rate in milliseconds -sampling local pin (10times per second) 0x14
ATIT->how many samples to collect
ATP0-P1->PWM configuration
	ATPX
ATIU->1/o input enable (UART)
ATAI->I/O input address-what address do I want to pay attention to?
	who do I want to be paired with
	

Talking to xBee

1. With the FTDI cable, connect the module to your computer. If the module has correct power, the green LED should be blinking. If it isn't, check the wiring and verify that the XBee is getting power.
   
   

   ---

2. need to figure out which serial port you are using. Plug in the FTDI cable, USB adapter, Arduino, etc.
   
   Open XBee_Terminal_Max.app
   

   ---

3. You want to configure for 9600 bps, 8 bit, No parity, 1 stop bit and no flow control
   

   ---

4. Now type in +++ (three plus signs) in quick succession. If the XBee is connected up properly you will get an OK in response
   
   

   ---

5. If you got an OK that means the XBee is powered and wired up correctly! If its not working, check:
   • Try again, be sure to wait 10 seconds between each attempt at typing in +++ and type the +'s quickly
     

     ---

   • Is the module powered? Green LED should be blinking
     

     ---

   • Are RX & TX swapped?
     

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   • Do you have the correct baud rate? By default it should be 9600 baud 8N1 no hardware handshake but if it has been used for something else the baud rate might be different.
     

     ---

   
   
   

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6. Next try typing in +++ (receive OK) and then AT and press return to get another OK This is basically how you can configure the XBee, by sending it AT commands (they all start with AT for ATtention). After a while, the XBee times out of configuration mode and goes back to pass-through connection mode. So if you want to get back to config mode, just type in +++ and it will start responding again.
   
   

   ---

7. Using terminal, you can change the baud rate using the ATBD command with a number afterwards that selects which baud rate to use:
   • 0 = 1200
   • 1 = 2400
   • 2 = 4800
   • 3 = 9600
   • 4 = 19200
   • 5 = 38400
   • 6 = 57600
   • 7 = 115200
   

   	
   +++ (get into AT mode)
   <- OK
   AT (check if xbee modem is responding)
   <- OK
    ATBD (get current baud rate as above)
   <- 3 (9600)
    ATBD 4 (set baud rate to 19200)
   <- OK
   ATBD (check again)
   <- 4
    ATWR (write the baud rate change to flash)
   <- OK
   

   
   
   

   ---

8. Reset the module, either by pulling the reset pin low for a second or removing power (unplugging cable, etc) To connect now, set the terminal to use 19200 baud, otherwise the module will not respond! You can set it back to 9600 baud by giving it the command ATBD 3 and then ATWRiting it to the flash
   
   

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Point-to-Point

1. Open the terminal program
   
   

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2. Configuring the Xbee Module

   To get the module into configuration mode, you need to send it three plus signs: +++ and there needs to be at least one second before and after during which you send no other character to the module. Note that this includes newlines or carriage return characters. Thus, if you're trying to configure the module from the computer, you need to make sure your terminal software is configured to send characters as you type them, without waiting for you to press enter. Otherwise, it will send the plus signs immediately followed by a newline (i.e. you won't get the needed one second delay after the +++). If you successfully enter configuration mode, the module will send back the two characters 'OK', followed by a carriage return.

   Send Command	Expected Response
   +++	OK<CR>

   Once in configuration mode, you can send AT commands to the module. Command strings have the form ATxx (where xx is the name of a setting). To read the current value of the setting, send the command string followed by a carriage return. To write a new value to the setting, send the command string, immediately followed by the new setting (with no spaces or newlines in-between), followed by a carriage return. For example, to read the network ID of the module (which determines which other Xbee modules it will communicate with), use the 'ATID command:

   Send Command	Expected Response
   ATID<enter>	3332<CR>

   To change the network ID of the module:

   Send Command	Expected Response
   ATID3331<enter>	OK<CR>

   Now, check that the setting has taken effect:

   Send Command	Expected Response
   ATID<enter>	3331<CR>

   Unless you tell the module to write the changes to non-volatile (long-term) memory, they will only be in effect until the module loses power. To save the changes permanently (until you explicitly modify them again), use the ATWR command:

   Send Command	Expected Response
   ATWR<enter>	OK<CR>

   To reset the module to the factory settings, use the ATRE command:

   Send Command	Expected Response
   ATRE<enter>	OK<CR>

   Note that like the other commands, the reset will not be permanent unless you follow it with the ATWR comamand.

   -> AT (check if xbee modem is responding)
   <- OK
   -> TID (get current PAN)
   <- 3332 (default, or something else)
   -> ATID 3137 (set new id)
   <- OK
   -> ATID (check again)
   <- 3137
   -> ATWR (write the change to flash)
   <- OK

   
   

   ---

3. Connect the xBee to the Arduino. For the first exercise the computer is going to talk to an Arduino.
   
   

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4. Start by first setting up the PAN ID and baud rate of baud rate of 9600 for the two modems.
   
   

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5. Connect one module to your microcontroller. First connect +5V and Ground to provide power. Make sure the XBee's green LED is blinking.
   
   

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6. Next connect the RX line (input) of the XBee to the TX line (output) of the microcontroller and vice versa.
   
   

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7. For the Arduino below you will be using a "Software Serial" program and use pin #2 as the RX and pin #3 as the TX. This allows you to use the default hardware USB serial port without conflicting.
   
   
   

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8. Connect the other module to a computer using an FTDI cable or similar.
   
   

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9. Open up a terminal to the computer's XBee and start typing into it - whatever you want. You should see the red LED on the other modem light up, indicating data is being received. If you don't see the red LED light up, check that you have compatible modules, matching baud rates and PAN IDs.
   
   

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10. Upload the sketch to Arduino:

    #include <NewSoftSerial.h>
    
    NewSoftSerial mySerial =  NewSoftSerial(2, 3);
    
    
    void setup()  {
      pinMode(13, OUTPUT);
      Serial.begin(9600);
      Serial.println("Goodnight moon!");
      // set the data rate for the SoftwareSerial port
      mySerial.begin(9600);
      mySerial.println("Hello, world?");
    }
    
    
    
    void loop(){
    
      if (mySerial.available()) {
          Serial.print((char)mySerial.read());
      }
      if (Serial.available()) {
          mySerial.print((char)Serial.read());
      }
      delay(100);
    }

    
    This will set up a point-to-point 'tunnel' between the two XBees. What is typed into the terminal at the computer will end up in the Arduino's Serial Monitor.
    

//Glove

ATRE,ID3456,MY1,DL2,IR64,IT1,D73,D45,IA2,WR

ATRE,ID3456,MY2,DL1,IR64,IT1,D63,D45,IA2,WR

• CTS flow control
• Analog-to-digital converter
• Digital input
Digital output

• Analog-to-digital converter
• Digital input
• Digital output

Analog inputs activated

ATD0 2

ATD1 2

ATD2 2

Sample rate 80 milliseconds: ATIR 50

1 sample per transmission: ATIT 1

/ /Arduinos

/ /Connecting two Arduinos

1. On the sender Arduino wire up a potentiometer. Program this Arduino so that the values are read and sent through the serial port.
   
   Use the map function to limit your input from 0-255:

   your_var=map(your_var, 0, 1023, 0, 255);

   When you send serial data, send it as BYTE

   Serial.println(your_var,BYTE);

   
   
   

   ---

2. On the receiver Arduino program wire up one Led. Program this Arduino so that the LED's intensity will change accordingly the pot value.
   
   To receive Serial use this code:

   if (Serial.available()) {
        // set the values to the incomingByte variable
        incomingByte = Serial.read();
   }

   
   
   

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3. Upload your programs
   
   

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4. Connect the Arduinos
   Tx on Arduino#1 -> connect to -> Rx on Arduino#2
   Rx on Arduino#1 -> connect to -> Tx on Arduino#2
   
   
   
   

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5. Test the program
   
   

   ---

And Again, but Wirelessly

1. Here is your sender code:

   int analogValue, val;
   
   void setup(){
       // start serial port at 19200 bps
       Serial.begin(19200);
   }
   void loop(){
   // read analog input
   analogValue = analogRead(2);
   // remap values
   val = map(analogValue, 0, 1023, 253, 0);
   
   //SYNC char
   Serial.print(254, BYTE); 
   Serial.print(val, BYTE);
   delay(150);
   }

   
   

   ---

2. Here is your receiver code:

   #define ledPin 9
   
   byte incomingByte, sensor;
   
   void setup() {
        // start serial port at 19200 bps
        Serial.begin(19200);
        Serial.println("Ready!");
       // led pins
       pinMode (ledPin, OUTPUT);
       delay(1000);
   }
   void loop() {
        // are there any bytes available on the serial port ???
        if (Serial.available()) {
            // assign bytes to the var incomingByte
             incomingByte = Serial.read();
            Serial.print(int(incomingByte));
            if ((int(incomingByte) == 254)) {
                sensor = Serial.read();
                Serial.print("Sensor 1 = ");
                Serial.print(int(sensor1));
             }
   
         }
       analogWrite (ledPin, sensor);
   
   }

   
   
   

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3. Wiring up sender:
   1. Arduino TX goes to Xbee RX and Arduino RX goes to Xbee TX.
   2. Power and GND to the pot.
   3. Analog Pin 2 to Pot
   
   
   

   ---

4. For the Receiver:
   1. Arduino TX goes to Xbee RX and Arduino RX goes to Xbee TX
   2. Digital Pin 9 connected through resistor 1 to positive end of the LED. GND to the negative end.
   
   
   

   ---

/ / Materials Needed

• 1 x Xbee chip
• 1 x 74lvc245 (5V to 3.3V buffer) 1 x 74hc245 buffer
• 1 x 10k resistor
• 1 x piezo 1 x switch
• 1 x 9V power supply, AC adapter or battery 1 x 3.3V voltage regulator

/ /Assignment

1. Write a song
2. Wire a circuit so that you interface the Arduino and Xbee.
3. When a switch is pressed on your circuit, send your song wirelessly to other xbee chips.
4. When a song is received from another group, play their theme song on your piezo.

byte names[] ={'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C'}; 
int tones[] = {1915, 1700, 1519, 1432, 1275, 1136, 1014, 956}; 

digitalWrite(speakerOut, LOW); 
for (count=0;count<=8;count++) { 
    if (names[count] == val) { 
        digitalWrite(speakerOut, HIGH);
        delayMicroseconds(tones[count]); 
        digitalWrite(speakerOut, LOW); 
        delayMicroseconds(tones[count]); 
    } 
}

/ /Common Mistakes

• 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.
  
  

• 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)
  
  

• 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)
  
  

/ /Lilypad

• XBee 802.15.4 OEM Module, Chip Antenna (30-100 m range)
• LilyPad XBee, http://faludi.com/lilypad
• Alligator clips
• 9 Volt battery or 3.3 - 3.7 Volt battery
• FTDI cable for programming with angle headers

SETUP

1. With female headers: This is how the board ships, and is a great setup for prototyping. You can easily swap out your radios to work with different models and antenna types.
   
   
2. Soldered directly to the board: This is for projects that are more in their final stages, where you know you won’t be swapping your radios. This secures the radio to the board and reduces the profile of your board tremendously, making it nice and slim so it lies nicely in your clothes! With the current version of the board, you’ll need to desolder and remove the female headers.

PIN LIST

POWER SOURCES

COMMON QUESTIONS ABOUT THE BOARD

What is a solder jumper?

Solder jumpers are really just a blob of solder that connects two pads together, completing a circuit. They form a semi-permanent connection, but can be removed with a simple soldering iron and a bit of solder wick. Later, they can be replaced to re-form the connection. This cycle can be performed repeatedly, though ideally not very often because eventually it will weaken the board. There are two solder jumpers on the LilyPad XBee board. One is by the d1 pad that completes a circuit for the LED lights and another by the vref pad that routes the supply current to the Voltage reference pin.

Why do lights have solder jumpers?

Sometimes you don’t want blinking lights on your board. Removing the upper solder jumper, by the d1 pin will disable both the ON and RSSI LED light.

Why does VRef pin have a solder jumper?

The Voltage reference pin tells the XBee what Voltage to set as the maximum level when reading an analog sensor. In most cases this will be the same as the XBee’ supply voltage so the jumper can be left in place. However, if you are using a different voltage for an analog sensor, then this jumper can be removed and that different voltage can be routed to the VRef pin.

Keep in Mind

• Never send more than about +4 Volts to the 3.3 pin. Use the + pin instead
  
  
• Conductive thread may be too resistive for power and ground, try fabric or wire
  
  
• XBee TX goes to Arduino RX and vice versa