openHAB Raspberry Pi Arduino XBee Led Zeppelin Music Machine

For many years my daughter called me in the evening in her room: “Daddy, please play the barrel organ!”

I usually asked: “How fast?”
And she replied: “Full speed!”
Okay.
After about ten years – my hands have become old and tired – I knew that I need a machine. I spoke to my daughter and we began to make plans.
After hours of thinking  we built a prototype with some toys:

 

And this is the funny result!
Attention: first you will hear nothing (or some noise from my stomach). Only when I touch my smartphone, you will hear LED ZEPPELIN! Yeah!

Here are some detailed images:

 

The ingredients for our openHAB Raspberry Pi Arduino XBee Led Zeppelin Music Machine:

• HABDroid running on a Samsung Galaxy smartphone
• a Raspberry Pi
  • with a XBee USB dongle
  • the openHAB runtime (extended with a custom XBee Binding)
• an Arduino UNO
  • with a motor shield
  • a wireless shield (with a XBee module fitted)
• an electric motor
• a barrel organ

The sequence of events:

1. my finger pushes the “Led Zeppelin on/off” switch on the HABDroid app on my smartphone
2. HABDroid sends the event over my WLAN to the openHAB runtime running on the Raspberry Pi
3. my openHAB binding receives the event, connects to the XBee USB dongle and sends “1” (0x31)
4. my Arduino UNO receives the “1” over the XBee receiver item on the Wireless Shield
5. my Arduino UNO sends “full speed” to the connected electronic motor
6. the electronic motor starts and drives the barrel organ

Here is a very basic list of what you have to do if you want to build the same crazy thing:

1. Install openHAB on a Raspberry Pi (must be connected to a LAN because we want to use HABDroid on a smartphone to control the openHAB runtime) – s. notes for openHAB
2. Plug a XBee USB dongle into the Raspberry Pi – s. notes for XBee
3. Do some Linux configuration on your Raspberry Pi – I use Raspbian – s. notes for Raspbian
4. Configure your openHAB runtime to provide a switch for HABDroid – s. notes for openHAB
5. Install a Java IDE for coding your custom XBee openHAB Binding for sending data over the XBee USB dongle and export it to your openHAB installation – s. notes for openHAB
6. Place your Arduino UNO with a Motor Shield and a Wireless Shield (with a XBee module fitted)
7. Install the Arduino IDE to create the “XBee” code and upload it to your Arduino – s. notes for the Arduino UNO
8. Find a solution for how you can connect your Motor Shield to an electric motor and finally to the barrel organ.
9. Think like a hobbyist and leave your family for two weeks to get it work!

Notes for Xbee:

For wireless commication between Raspberry Pi and the Arduino UNO we use two XBee modules. One as ZigBee Coordinator, the other one as ZigBee Router, both in API mode.
TIP: if you want to configure and test the XBee modules in a comfortable way, do it with the XCTU GUI! Here’s a screenshot:

Notes for Raspbian (or the OS which you run on your Raspberry Pi):

1. Install Rxtx: sudo apt-get install librxtx-java – this installs librxtxSerial.so into /usr/lib/jni which we need for our XBee communication
2. find our where your XBee USB dongle is mounted. In my case it is: /dev/ttyUSB0
3. go to /dev and find out the group name of your XBee USB dongle. In my case it’s the group dialout
4. add your openhab user to the dialout group

Notes for openHAB:

Edit the openHAB start scripts on your Raspberry Pi. In my case: /usr/share/openhab/bin/openhab.sh
You’ll find a part like this one:

...
JAVA_ARGS_DEFAULT="-Dosgi.clean=true \
 -Dgnu.io.rxtx.SerialPorts=/dev/ttyUSB0 \
 -Declipse.ignoreApp=true \
 -Dosgi.noShutdown=true \
 -Djetty.port=${HTTP_PORT} \
 -Dopenhab.configfile="${OPENHAB_CONF_DIR}/configurations/openhab.cfg" \
 -Dopenhab.configdir="${OPENHAB_CONF_DIR}/configurations" \
 -Dopenhab.logdir="${OPENHAB_LOG_DIR}" \
 -Dsmarthome.userdata="${OPENHAB_USER_DATA_DIR}"
 -Djetty.home="${OPENHAB_DIR}" \
 -Djetty.port.ssl=${HTTPS_PORT} \
 -Djetty.config="${OPENHAB_CONF_DIR}/jetty" \
 -Djetty.logs="${OPENHAB_LOG_DIR}" \
 -Djetty.rundir="${OPENHAB_DIR}" \
 -Dfelix.fileinstall.dir="${OPENHAB_DIR}/addons" \
 -Dfelix.fileinstall.filter=.*\\.jar \
 -Djava.library.path="${OPENHAB_DIR}/lib:/usr/lib/jni" \
...

1. I added the line starting with “-Dgnu.io.rxtx.SerialPorts” (don’t forget to use the name of your XBee USB dongle mounting)
2. and I extended the java.library.path parameter with the /usr/lib/jni path (s. below Rxtx installation)

The sitemap configuration:

Frame label="Music Machine" {
  Switch item=MusicMachineSwitch label="Led Zeppelin on/off"
}

My items configuration:

Switch MusicMachineSwitch  	"Xbee Music Machine Switch" { mzxbee }

My setting for the openhab.cfg:
These are some configurations, which I use in my Java code. I want to communicate with 9600 baud, the mounting point for my Xbee USB dongle is /dev/ttyUSB0 and the MAC address of the receiver is “00 13 A2 00 40 A2 5A EC”

mzxbee:baud=9600
mzxbee:comPort=/dev/ttyUSB0
mzxbee:address=0013A20040A25AEC

For our custom XBee openHAB Binding we use this Java API:
XBee Java Library

Here’s the important part of the Java code:

logger.debug("Instantiating device with comPort " + comPort + " and " + baud + " baud...");
XBeeDevice myDevice = new XBeeDevice(comPort, baud);
			
logger.debug("Opening device...");
myDevice.open();
			
logger.debug("Instantiating address...");
XBee64BitAddress addr64 = new XBee64BitAddress(address);
			
logger.debug("Instantiating RemoteXBeeDevice device...");
RemoteXBeeDevice myRemoteXBeeDevice = new RemoteXBeeDevice(myDevice, addr64);

logger.debug("********************* Sending sync data: " + value + " > byte value: " + Character.digit(value,16));
myDevice.sendData(myRemoteXBeeDevice, new byte[]{ (byte)value });

logger.debug("Closing device..."); 
myDevice.close();

value can be 1 to turn the music machine on and 0 to turn it off.

Notes for the Arduino UNO

This is the code for the Arduino UNO. I want to let a LED blink, when the Arduino starts. The same LED shall light, when the music plays.

#include <XBee.h>

int incomingByte = 0;	// for incoming serial data
int dirA = 12;
int brake = 9;
int mspeed = 3;

const int led = 7;

Rx16Response zbRx = Rx16Response();

XBee xbee = XBee();

void setup() {

  Serial.begin(9600);	// opens serial port, sets data rate to 9600 bps
  xbee.setSerial(Serial);

  pinMode(led, OUTPUT);

  pinMode(dirA, OUTPUT);
  pinMode(brake, OUTPUT);
  pinMode(mspeed, OUTPUT);

  // blink twice at startup
  digitalWrite(led, LOW);
  delay(1000);

  digitalWrite(led, HIGH); // first blink
  delay(50);
  digitalWrite(led, LOW);
  delay(200);
  digitalWrite(led, HIGH); // second blink
  delay(50);
  digitalWrite(led, LOW);
}

void loop() {
  digitalWrite(dirA, LOW);
  digitalWrite(brake, LOW);

  // send data only when you receive data:
  if (Serial.available() > 0) {
    // read the incoming byte:
    incomingByte = Serial.read();

    if(incomingByte == '0'){
      digitalWrite(led, LOW);
      analogWrite(mspeed, 0);
    }
    else if(incomingByte == '1'){
      digitalWrite(led, HIGH);
      analogWrite(mspeed, 255);
    }    

  } 

}

To-Dos:

1. add speed control! More speed! Much more!
2. … ideas …?