[FMN#06] : Let's dweet with raspberry pi

29 Aug 2014

In my last post, I introduced Dweet.io and explained how to dweet from your raspberry pi. in this post, I'm going one step ahead and wiring together my Enocean-Py library with dweepy and start dweeting my Enocean sensor data.

Let's start dweeting

The whole idea is this - my raspberry pi, my first python script will first decode a received radio telegram with Enocean-Py and extract the rocker switch state. Then it will dweet this information to the public. On my desktop, I'll be running a second python script which will display as and when a new new dweet is posted by my raspberry pi. This demo utilizes the real time streaming capability of dweepy library and also showcases Enocean-Py library. As a word of caution, Enocean-Py is still under development and I recommend you always to update Enocean-Py before using it.( Details as in this post [FMN#03] : Decoding Enocean Protocol with Enocean Py )

Script for Raspberry pi

I'm assuming that you have already installed dweepy as explained in this post. First create a folder for this demo in your raspberry pi. Say this is '/home/pi/dweet_demo'. Now enter this directory and clone Enocean-Py repository by

git clone https://github.com/v-i-s-h/Enocean-Py.git

Now create a file named 'demo_sender.py' and contents as below :

#  demo_sender - a demo for using dweepy and enocean-py for dweeting enocean data.

import sys
import time
import dweepy
sys.path.insert( 0, "./Enocean-Py/src/" );
import EO
import ESP

'''
Function    : main
Description : main function
Arguments   : none
Returns     : none
'''
def main():
    print "\t\t*************************************************"
    print "\t\t**    Forget Me Not 2014 - Dweeting demo       **"
    print "\t\t**               by vish                       **"
    print "\t\t*************************************************"

    ttyPort = "/dev/ttyAMA0"
    print "\tUsing serial port : " + ttyPort + '\n'

    hEOGateway = EO.connect( ttyPort )
    # better to wait a little for connection to establish
    time.sleep( 0.100 )

    # this is your thing ID, change accordingly
    thingId = "fmn2014_vish_raspberrypi"
    # this hash table holds our dweet message
    myDweet = {}

    try:
        while( True ):
            rawResp = EO.receiveData( hEOGateway )
            if rawResp:
                pkts = ESP.decodeRawResponse( rawResp )
                for pkt in pkts:
                    myDweet = {}    # clear old data
                    myDweet['sender'] = 'enocean_py demo'
                    # currently no response radio decoding is implemented in Enocean Py
                    # I'm just checking whether the radio is from my rocker switch RORG = F6
                    # and then blindly checks for the bits set.
                    if pkt['data_recv'][0] == 0xF6:     # is this my rocker switch
                        # assuming we got a radio telegram from rocker switch
                        if pkt['data_recv'][1] == 0x70:
                            print "Channel B : OFF ",
                            myDweet['Channel B'] = 'OFF'
                        if pkt['data_recv'][1] == 0x50:
                            print "Channel B : ON  ",
                            myDweet['Channel B'] = 'ON'
                        if pkt['data_recv'][1] == 0x30:
                            print "Channel A : OFF ",
                            myDweet['Channel A'] = 'OFF'
                        if pkt['data_recv'][1] == 0x10:
                            print "Channel A : ON  ",
                            myDweet['Channel A'] = 'ON'
                        if pkt['data_recv'][1] == 0x00:
                            print "Rocker Released.",
                            myDweet['Rocker0'] = 'Released'
                        dweepy.dweet_for( thingId, myDweet );
                        print "......dweeted"
    except KeyboardInterrupt:
        print "\nExiting Demo"
        EO.disconnect( hEOGateway )
        print "Bye..bye.. :) "

if __name__ == "__main__":
    main()

Once you are done, you can save and close the file. Remember to change the 'thingId' to your thing's id.

Desktop Viewer

Now we'll create a desktop viewer application for viewing the dweets send by out beloved raspberry pi. What we will do is we'll use the realtime streaming capability of dweepy library and create a python script which will decode and show the dweet from raspberry pi.

Off course you need to install dweepy in your PC also.

Now create a new file name 'dweet_viewer.py' and copy paste these contents to the file.

#  dweet_viewer.py - a desktop application to view your thing's dweets

import json
import dweepy

def main():

    # replace with your thing Id
    thingId = "fmn2014_vish_raspberrypi"

    print "\t\t*************************************************"
    print "\t\t**    Forget Me Not 2014 - Dweet Viewer        **"
    print "\t\t**               by vish                       **"
    print "\t\t*************************************************"

    for dweetJSON in dweepy.listen_for_dweets_from( thingId ):
        if type(dweetJSON) is int:
            continue
        dweet = json.loads( dweetJSON )
        timeStamp = dweet['created']
        content = dweet['content']
        for items in content.keys():
            print "At " + timeStamp + " \"" + items + "\" updated to \"" + content[items] + "\"";

if __name__ == "__main__":
    main()

Save and close the file.

Running the demo

To run the demo, first start your 'dweet_viewer.py' script in your PC and then starting 'demo_sender.py' in your raspberry pi. Now press and release your demo switch and see what happens at both PC and raspberry pi.

Here is a video of demo running.