View source for Interfacing with Python

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__TOC__

== Introduction ==
In this tutorial you will learn how to programmatically communicate with the Tmote Sky using the Python programming language. This will enable you to do such things as process data from your mote in real-time. In addition, you can send commands or data back to the mote to impact its operation. The possibilities are endless.

== Setup ==
This tutorial was written and tested using the following:
* Contiki 2.7
* Python 2.7.3 (and pySerial)
* Ubuntu 12.04
* Tmote Sky

Connect the Tmote Sky to your computer using a USB cable and install the Sky Shell example. See the @Sky Shell@ tutorial for instructions on how to do this. We use this example so that we’ll have data to ensure that we are correctly reading and writing to the mote.

== Step 1 ==

Create a Python file called serial.py containing the following code:
 #!/usr/bin/python
 import serial
 ser = serial.Serial(
    port='/dev/ttyUSB0',\
    baudrate=115200,\
    parity=serial.PARITY_NONE,\
    stopbits=serial.STOPBITS_ONE,\
    bytesize=serial.EIGHTBITS,\
    timeout=0)
 print("connected to: " + ser.portstr)
 ser.write("help\n");
 while True:
            line = ser.readline();
            if line:
              print(line),
 ser.close()

Note: 
This code assumes the mote you are using for this tutorial is connected to ‘’/dev/ttyUSB0’’. Please check this using the ‘’make motelist’’ command as shown in the figure below. If the mote you are using is connected to a different device file, please modify the Python code accordingly.

== Step 2 ==

Run the Python code using the command:

 python serial.py

You should see output similar to the following:
 connected to: /dev/ttyUSB0
 Available commands:
 ?: shows this help
 binprint: print binary data in decimal format
 blink [num]: blink LEDs ([num] times)
 collect: collect data from the network
 collect-view-data: sensor data, power consumption, network stats
 echo <text>: print <text>
 energy: print energy profile
 exit: exit shell
 hd: print binary data in hexadecimal format
 help: shows this help
 kill <command>: stop a specific command
 killall: stop all running commands
 mac <onoroff>: turn MAC protocol on (1) or off (0)
 netcmd <command>: run a command on all nodes in the network
 nodeid: set node ID
 null: discard input
 packetize: put data into one packet
 power: print power profile
 powerconv: convert power profile to human readable output
 powertrace [interval]: turn powertracing on or off, with reporting interval <interval>
 quit: exit shell
 randwait <maxtime> <command>: wait for a random time before running a command
 reboot: reboot the system
 repeat <num> <time> <command>: run a command every <time> seconds
 rfchannel <channel>: change CC2420 radio channel (11 - 26)
 routes: dump route list in binary format
 send <rexmits>: send data to the collector node, with rexmits hop-by-hop retransmissions
 sense: print out sensor data
 senseconv: convert 'sense' data to human readable format
 size: print the size of the input
 time [seconds]: output time in binary format, or set time in seconds since 1970
 timestamp: prepend a timestamp to data
 txpower <power>: change CC2420 transmission power (0 - 31)
 5.0: Contiki>

== Understanding the Code ==


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