Agile Manifesto

Manifesto for Agile Software Development

Individuals and interactions over processes and tools

Working software over comprehensive documentation

Customer collaboration over contract negotiation

Responding to change over following a plan

That is, while there is value in the items on

the right, we value the items on the left more.

Hacking Kankun Smart Wifi Plug

Kankun Smart Wifi Plug

The Kankun "Small K" (KK-SP3) Smart Wifi Plug Socket is an inexpensive device (~$20) that lets you switch an outlet on and off over Wi-Fi.

Smart Plug is a Controllable OpenWRT Linux BusyBox

Designed to be controlled by a smart phone, some engineering minds posted on Hackaday a way to control the device from any web browser or SSH client.  It turns out the Smart Plug is running a version of OpenWRT, which is basically a minimal BusyBox Linux environment (BusyBox: The Swiss Army Knife of Embedded Linux). It also has SSH access turned on by default, and was just a matter of determining the default password (admin, 1234, or p9z34c). Once you have SSH access you can either control the relay directly, or add a CGI script to control from a web browser.

root@koven:~# cat /etc/openwrt_release
DISTRIB_ID="OpenWrt"
DISTRIB_RELEASE="Bleeding Edge"
DISTRIB_REVISION="r39365"
DISTRIB_CODENAME="barrier_breaker"
DISTRIB_TARGET="ar71xx/generic"
DISTRIB_DESCRIPTION="OpenWrt Barrier Breaker r39365"

AliExpress

The Kunkun Smart Plug can be picked up on AliExpress for about $20.

"AliExpress is like eBay worldwide, but a lot bigger." (src)

Smart Plug package

There are a lot of options for purchase, just make sure you pick the US connector version (example), or you will need to buy an adapter (a mistake I made with the first one I ordered).

Smart Plug - US Connector Version

If you do get the wrong one, the front "female" receptacle connector was a universal connector, but the back "male" plug connector is the problem and you have to buy an adapter, so your device will end up looking like this:

Smart Plug - Chinese Connectors with US adapter

I should mention that one plug took 2 weeks to arrive and another took just shy of a full month. Different sellers, but both coming from China.

Factory Reset

As we make changes to the wireless settings, we can recover to the original factory settings by pressing and holding an almost-invisible white button on the surface of the plug for 4 seconds.

Configuring to SmartPlug Wireless Network

To get access and control to the Smart Plug, we first need to configure it.

Out of the box the Smart Plug is set as a Wireless Access Point, with an SSID of OK_SP3 (no password). To be useful, we will need to connect to this temporary access point and configure the device to connect to our home wireless network.

To configure the wireless, we can either:

1. Connect to the SSH service (default ip: 192.168.10.253) and modify the wireless files manually

or

2. We can use the Smart Phone Android/iOS app to configure the Smart Plug

I think the initial setup is easier with the app, so...

Configuring to SmartPlug Wireless Network - Android App Method

1. Download and install the Android Kankun "SmartPlug" app. (I assume the app on iOS is the same, but I haven't verified this)

For reference, I installed the app from the Google Play Store, but the instructions also provide a URL to download the app file: http://kk.huafeng.com:8081/android/Smartwifi.apk

2. Connect your Android Smart phone to the OK_SP3 network.

3. Start the SmartPlug app and click the "Config" button. Note: the "Device" page will be empty, unless you have already configured devices.

4. This is where we will change the Smart Plug's wireless network settings to our home network. Change the "Wifi" item to your home SSID (sorry no discovery option here). Change the Password to your home's wireless password. Ignore the "Encryption" option. Finally click the Configuring button to save the changes.

5. The Smart Plug should now be on your home's wireless network, and your Smart Phone will have been auto disconnected from the OK_SP3 network and also back on your home network. Check the status of the blue LED on the Smart Plug. If the LED is off, everything is good. If the light is blinking, it was unable to connect to your home wireless network.

6. Now check the "Device" list. Your Smart Plug should now be in the device list. Select the device.

Note: The device's Ethernet address (MAC) is also listed. Take note of the MAC, as you will want to check your DHCP server's logs to determine the IP address of your Smart Plug.

7. From here, we can quickly test the Smart Plug. We will be presented with a visual "on/off" button. Click the "on/off" a few times until you are satisfied. You will hear the relay switch on and off, or if you have something plugged into the Smart Plug, you will see it turn on and off.

7. Check your home's DHCP logs to find out what the new IP address of your Smart Plug is. Next we will connect to the Smart Plug over SSH.

Example:

dnsmasq-dhcp: DHCPDISCOVER(eth0) 00:15:61:bc:42:af
dnsmasq-dhcp: DHCPOFFER(eth0) 10.10.10.222 00:15:61:bc:42:af
dnsmasq-dhcp: DHCPREQUEST(eth0) 10.10.10.222 00:15:61:bc:42:af
dnsmasq-dhcp: DHCPACK(eth0) 10.10.10.222 00:15:61:bc:42:af

Configuring to SmartPlug Wireless Network - SSH Method

default /etc/config/wireless:

...

config wifi-iface
        option device radio0
        option network lan
        option mode ap
        option ssid OK_SP3
        option encryption none

change /etc/config/wireless:

...

config wifi-iface
        option device radio0
        option network wwan
        option ssid 'YOURSSID'
        option mode sta
        option encryption psk
        option key 'YOUR_WPA_KEY'

append /etc/config/network: (thanks Michael Liddle)

  config interface 'wwan'
  option proto 'dhcp'

After saving this file, reboot the Smart Plug and it should be connected to your home network. If the connection fails, perform the "factory reset" procedures to reset the network settings.

# reboot

SSH Password

Using your favorite SSH client, connect to the Smart Plug's IP address. Use "root" for the username, and "p9z34c" as the password (older models may have used "admin" or "1234").

$ ssh root@10.10.10.222
root@10.10.10.222's password:

BusyBox v1.19.4 (2014-03-27 17:39:06 CST) built-in shell (ash)
Enter 'help' for a list of built-in commands.

  _    _               _    _
 | | _-_| _____ _____  | | _-_| _____ ____
 |  -_-  |     ||     ||  -_-  |     ||    |
 | |-_   |  -  ||  |  || |-_   |  -__||   _|
 |  _ -_ |_____||__|__||  _ -_ |_____||__|
 |_| -__|  S M A L L   |_| -__| S M A R T
 -----------------------------------------------------
 KONKE Technology Co., Ltd. All rights reserved.
 -----------------------------------------------------
  * www.konke.com            All other products and
  * QQ:27412237              company names mentioned
  * 400-871-3766             may be the trademarks of
  * fae@konke.com            their respective owners.
 -----------------------------------------------------
root@koven:~#

You can then change the default password with the 'passwd' command.

# cat /etc/shadow | grep root
root:$1$4a45vajh$LVbmwoCs84PwyB.r2UdIN1:16185:0:99999:7:::

# passwd
Changing password for root
New password:
Retype password:
Password for root changed by root

Control Relay

Turning on and off the relay is really easy:

# turn relay on
echo 1 > /sys/class/leds/tp-link:blue:relay/brightness

# turn relay off
echo 0 > /sys/class/leds/tp-link:blue:relay/brightness

Web Interface

cnxsoft posted a simple CGI script (relay.cgi) to control the relay from a web interface:

Simply create the directory /www/cgi-bin/ and create the relay.cgi script as follows and give execute permission (chmod +x /www/cgi-bin/relay.cgi).

#!/bin/sh
echo "Content-Type: text/plain"
echo "Cache-Control: no-cache, must-revalidate"
echo "Expires: Sat, 26 Jul 1997 05:00:00 GMT"
echo

RELAY_CTRL=/sys/class/leds/tp-link:blue:relay/brightness

case "$QUERY_STRING" in
 state) 
  case "`cat $RELAY_CTRL`" in
   0) echo "OFF"
   ;;
   1) echo "ON"
   ;;
  esac
 ;;
 on) 
  echo 1 > $RELAY_CTRL
  echo OK
 ;;
 off) 
  echo 0 > $RELAY_CTRL
  echo OK
 ;;
esac

Open a browser and use the following URLs to control the relay:

http://your_device_ip/cgi-bin/relay.cgi?on

http://your_device_ip/cgi-bin/relay.cgi?off

Power Limits

The Smart Plug has a max current of 10 A or 2,200 W. A fire may be caused by exceeding these limits.

Google+ Group

Hacking the the Smart Plug now has a community group setup on Google+ Groups.

USB Connectors

Found this wonderful reference chart of the various popular USB connectors.  The male "plug" adapter inserts into the female "jack/receptacle".

Big Ben Clock - Raspberry Pi

We mounted a large clock on the wall of our vaulted ceiling and wanted to give it a little more pizzazz. I wanted to give it a Big Ben feel, so I added some speakers, a Raspberry Pi, a little code, and voilà! We now have a mini Big Ben of our own.

With a Wifi connector I am also able to remotely push other audio sounds to the speakers. Think speaker front end for a makeshift security system, or other audio states of your home automation. The possibilities are endless.

Demonstration

YouTube: Big Ben Clock - Big Ben Clock - Raspberry Pi

Code

The following is the code I wrote for the cronjob schedule and bash script to determine which audio file to play.

cronjob schedule:

# hourly from 7am to 10pm
0 7-22 * * *  /opt/big_ben/big_ben.sh > /dev/null

big_ben.sh:

#!/bin/bash

# Author: Kenneth Burgener  2014
# Purpose: Determine hour and play appropriate Big Ben MP3

# crontab: (from 7am and 10pm)
# 0 7-22 * * *  /opt/big_ben/big_ben.sh > /dev/null

# Get hour (1-12) for mp3 file
HOUR=`date +%l`
HOUR=$(( $HOUR ))

# Get military hour (1-24) for math below
MILHOUR=`date +%k`
MILHOUR=$(( $MILHOUR ))

# Set audio volume depending on time of day
if [ $MILHOUR -le 8 -o $MILHOUR -ge 20 ] ; then
    # 8am and earlier, 8pm and later
    #/usr/bin/amixer set PCM 80% > /dev/null
    /usr/bin/amixer set PCM 90% > /dev/null
else
    # 9am to 7pm
    #/usr/bin/amixer set PCM 95% > /dev/null
    /usr/bin/amixer set PCM 91% > /dev/null
fi

/usr/bin/mpg123 /opt/big_ben/audio/big_ben_$HOUR.mp3 2> /dev/null

Big Ben Audio

I found a good quality mp3 file that had the full 12 chimes. I then used Audacity to chop the file into smaller versions for the appropriate hour chimes.

• big_ben.zip
• big_ben_1.mp3
• big_ben_2.mp3
• big_ben_3.mp3
• big_ben_4.mp3
• big_ben_5.mp3
• big_ben_6.mp3
• big_ben_7.mp3
• big_ben_8.mp3
• big_ben_9.mp3
• big_ben_10.mp3
• big_ben_11.mp3
• big_ben_12.mp3
• big_ben_12.mp3

Twitter Logger with Python

Want a more modern method for simple logging and notifications? Twitter is very popular, but it normally too "noisy" for me to follow for social messages. Add a bit of tech and now I have a reason to check Twitter at least once a day, or follow the events on my phone.

I had read articles in both Linux Journal and The MagPi Magazine about engineering minds using Twitter to receive notifications when certain events occur. I decided to take this a step further and create a tiny Twitter logger script for all of my Raspberry Pis. I now receive notifications for all kinds of events, such as:

• Daily "alive" notifications
• Reboots, power cycles
• Changes in dynamic IP address
• GPIO event triggers (think security alarm, garage door, sprinkler system, etc)
• And anything else that fancies me at the moment

Code

How complicated is the Python? Easy. Only 3 lines (ignoring the line wrapping and commented debug code):

import twitter

api = twitter.Api(consumer_key='XXX',
                  consumer_secret='XXX',
                  access_token_key='XXX',
                  access_token_secret='XXX')

status = api.PostUpdate('This is my status update')

# print status.text

To use this code you will need to first generate your Twitter App API Access Keys and also install the python-twitter Python package.

Twitter App API Access Keys

Step 1 - Twitter Account: So how does one get started?  Well first, you need a Twitter account.  I assume you already have one, or at least don't need help creating one.

Step 2 - Mobile Phone: Unfortunately, your code will only be able to read status updates, unless you tie a mobile phone number to your account. Once you have validated your mobile phone, you will then be able to write/post status updates as well. Go to your account Settings and select the Mobile section. Add your mobile phone number, and wait for the validation code to appear on your phone. (note: I did attempt to try a couple of free burner mobile phone numbers, none of which ever received the validation code)

"You must add your mobile phone to your Twitter profile before granting your application write capabilities. Please read https://support.twitter.com/articles/110250-adding-your-mobile-number-to-your-account-via-web for more information"

Step 3 - Twitter App: Next, we need to create a Twitter App. This is nothing more than a method to get access to your api keys. Browse to https://apps.twitter.com/ and click the "Create New App" button.

Fill in the Name, Description and Website fields, then accept the agreement and continue.

The important field is the Name field as it has to be unique among all Twitter Apps. I just used my twitter account name, as I assumed no one else would be using that for an app name.

The Website field has to be populated, but won't be used. Put some temporary website and continue.

The Callback URL can be ignored.

Step 4 - Access Level: After the Twitter App has been created, find the Application Settings section and modify the Access level option by clicking the Modify App Permission link.  Change the access level from Read Only to Read and Write.  If you receive a warning about your mobile phone number, go back to step 2.

Step 5 - Access Keys: Finally, find the Application Settings section again and click the Manage Keys and Access Tokens link. You will find the consumer keys at the top of the page. Under the Your Access Token section, click the Create My Access Token button to generate the access tokens. If it isn't obvious the keys match the code variables as such:

consumer_key = "Consumer Key (API Key)"
consumer_secret = "Consumer Secret (API Secret)"
access_token_key = "Access Token"
access_token_secret = "Access Token Secret"

Now with your access keys, you can begin using the code above to update your twitter status with various notifications.

python-twitter

The python-twitter package "provides a pure Python interface for the Twitter API." To install the python-twitter package, simply use pip.

$ sudo pip install python-twitter

That was easy.

Check Status Code

The previous code showed how we can post a new update, but what about getting our current status, or someone else's?

import twitter
api = twitter.Api(...)

# get my timeline
statuses = api.GetUserTimeline()

# get a specific user's timeline:
# statuses = api.GetUserTimeline(screen_name=SCREEN_NAME)

# show latest message only:
print statuses[0].text

# show all returned messages:
for s in statuses:
       print s.text

Catch Errors

There are a few important errors that you will probably run across, and should handle:

Authentication failure: (check your keys, especially for accientally copied space characters)

twitter.error.TwitterError: [{u'message': u'Could not authenticate you', u'code': 32}]

Too long of a message: (shorten your message)

twitter.error.TwitterError: [{u'message': u'Status is over 140 characters.', u'code': 186}]

Duplicate message: (don't repeat messages or add a unique id, like time)

twitter.error.TwitterError: [{u'message': u'Status is a duplicate.', u'code': 187}]

User does not exist: (check the user name you are trying to query)

twitter.error.TwitterError: [{u'message': u'Sorry, that page does not exist', u'code': 34}]

test

Cronjob

I updated the twitter script to accept a message from the command line, and then added it to my cronjob:

@daily      /usr/bin/python /usr/local/bin/twitter alive
@reboot     /usr/bin/python /usr/local/bin/twitter reboot

Tips

#1 To be able to group and sort messages, I would recommend using the power of the hashtag. Pick a unique identifier (maybe your username) and append a category like this:

system startup #oeey_garage_pi

#2 To avoid the "Status is a duplicate" you may also wish to append a unique ID to all messages. I like to use the current linux epoc time, like this:

system startup #oeey_garage_pi (1415571010)

The updated posting code would look like this:

import time
...
status = api.PostUpdate('{message} #{category} ({id})'.format(
        message=message,
        category=category,
        id=int(time.time())

Issues

InsecurePlatformWarning:

/usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning

Solution: either ignore the warning or upgrade to at least Python 2.7.9 (or change code to use pyOpenSSL).

Other Libraries

If Python is not your thing, there a number of other Twitter libraries for various other programming platforms.

That's All Folks

Good luck, and have a good time playing with Python and Twitter.

Introduction to the Google Calendar API (HOWTO)

I have used Google Calendars to schedule and control a number of projects (eg. sprinkler system, alarm clock, etc) .  The following How To will get you started.  You will of course need a google account.

Create Project

1) Start by visiting the Google Developers Console

and create a new project.

2) Select the project and navigate on the left menu to APIs & auth then APIs and enable Calendar API for this project.  You can disabled all other APIs if you only need Calendar access.

3) Next, select the Consent screen menu option from the APIs & auth menu.  Enter a Product Name and select an Email Address.  If you do not do this step, you will get a Error: invalid_client error later on.

4) Next, select the Credentials menu option from the APIs & auth menu.  Under OAuth select Create new Client ID.

5) For the Create Client ID select Installed application for Application Type and select Other for Installed Application Type and finally click the Create Client ID button.

6) After the ID has finished being created, click the Download JSON button.  Save and rename the file as something simple like client_secret.json.

This json file contains your API credentials needed to access the Google Calendar APIs.

Install Google API Libraries

1) Install the Google API Libraries using Python's PIP installer:

$ sudo pip install --upgrade google-api-python-client

gflags may or may not be needed, depending on what code you use: (may be optional)

$ sudo pip install --upgrade python-gflags

If you would prefer alternatives, view the Google APIs Client Library for Python page.

Authorize Application

Next we will need to run our application and authorize it against the desired account.

1) Clone my sample code:

# git clone https://github.com/oeey/gcalendar.git

The sample code is just a slight modification from the Getting Started Sample Code.  The Google sample code has some outdated code that will throw some obsoleted warnings.

2) The application has not been authorized to an account yet.  Run the application once and you will be asked to paste a validation URL into your browser.  Login to your desired target account (with the calendars you want to access) and then paste the validation URL into your browser.

For convenience I have a first_auth.py script that is the same script as the gcalendar.py script, but terminates after authorization.  You can run any of the scripts to complete this authorization step.

The first_auth.py is pretty simple:

from apiclient.discovery import build
from oauth2client.file import Storage
from oauth2client.client import AccessTokenRefreshError
from oauth2client.client import OAuth2WebServerFlow
from oauth2client.tools import run_flow
from oauth2client.client import flow_from_clientsecrets

def main():
    scope = 'https://www.googleapis.com/auth/calendar'
    flow = flow_from_clientsecrets('client_secret.json', scope=scope)

    storage = Storage('credentials.dat')
    credentials = storage.get()

    class fakeargparse(object):  # fake argparse.Namespace
        noauth_local_webserver = True
        logging_level = "ERROR"
    flags = fakeargparse()

    if credentials is None or credentials.invalid:
        credentials = run_flow(flow, storage, flags)

if __name__ == '__main__':
    main()

You may notice the "fakeargparse" code. The run_flow() call wants the flags to be set from the parameters pulled from argparse. I think that is overkill for what I needed, so I just created a fake container so run_flow() wouldn't complain.

Run the first_auth.py script to collect the application authorization.

$ python first_auth.py
Go to the following link in your browser:

    https://accounts.google.com/o/oauth2/auth?scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fcalendar&redirect_uri=urn%3Aietf%3Awg%3Aoauth%3A2.0%3Aoob&response_type=code&client_id=1039XXXXXXXXXXXXXXXXXXXXXXXXXXcs46gdj2.apps.googleusercontent.com&access_type=offline

Enter verification code:

3) Copy the URL into the browser and accept the permissions.

4) You will be presented with a code, to which you will then enter back into the prompt of the first_auth.py application.  The authorization will be stored in the credentials.dat file for future requests.

$ python first_auth.py
Go to the following link in your browser:

    https://accounts.google.com/o/oauth2/auth?scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fcalendar&redirect_uri=urn%3Aietf%3Awg%3Aoauth%3A2.0%3Aoob&response_type=code&client_id=46XXXXXXXXXX2-bXXXXXXXXXXXXXusvh6.apps.googleusercontent.com&access_type=offline

Enter verification code: 4/WzAQfXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX2vw2M2Pl7OykQI
Authentication successful.

Now that we have our API credentials and are authorized to access an account, we can begin to play with the Google Calendars.

View Upcoming Events

The upcoming.py script builds off of the first_auth.py script, cycles through the next few upcoming calendar events and displays the event titles.

...
    if credentials is None or credentials.invalid:
        credentials = run_flow(flow, storage, flags)

    http = httplib2.Http()
    http = credentials.authorize(http)
    service = build('calendar', 'v3', http=http)

    print "Upcoming Events:"
    request = service.events().list(calendarId='primary')
    while request != None:
        response = request.execute()
        for event in response.get('items', []):
            print event.get('summary', 'NO SUMMARY')
        request = service.events().list_next(request, response)

This script defaults to the primary calendar associated with the account.

Calendar ID

The previous script defaults to the primary calendar associated with the account.  If you wish to specify an alternate calendar, you will need the Calendar ID.  A calendar's ID can be found on the Calendar Details setting page (same page you can change a calendar's name on).  Look for the Calendar Address line, and the Calendar ID will be in the parenthesis.  It will look something like "a3sd5221ap2qe5ksbev3ip4@group.calendar.google.com".

Next 12 Hours of Events

Finally, to specify a time range for events, I use the following code in my gcalendar.py script.  This code will collect the next 12 hours worth of events.

  ...

    service = build('calendar', 'v3', http=http)

    # get the next 12 hours of events
    epoch_time = time.time()
    start_time = epoch_time - 3600  # 1 hour ago
    end_time = epoch_time + 12 * 3600  # 12 hours in the future
    tz_offset = - time.altzone / 3600
    if tz_offset < 0:
        tz_offset_str = "-%02d00" % abs(tz_offset)
    else:
        tz_offset_str = "+%02d00" % abs(tz_offset)
    start_time = datetime.datetime.fromtimestamp(start_time).strftime("%Y-%m-%dT%H:%M:%S") + tz_offset_str
    end_time = datetime.datetime.fromtimestamp(end_time).strftime("%Y-%m-%dT%H:%M:%S") + tz_offset_str

    print "Getting calendar events between: " + start_time + " and " + end_time

    events = service.events().list(calendarId='primary', timeMin=start_time, timeMax=end_time, singleEvents=True).execute()singleEvents=True).execute()
    #pprint.pprint(events)
    for event in events['items']:
        print event["summary]

And this is the basis for the code I use to schedule my sprinkler system with.

X10

X10 - Lamp Module

I have been working on adding some home automation with X10 modules.

"X10 is a protocol for communication among electronic devices used for home automation (domotics). It primarily uses power line wiring for signaling and control, where the signals involve brief radio frequency bursts representing digital information." ^ref

I am using an X10 CM11A serial adapter module, connected to RaspberryPi, to control the X10 modules. I use the Linux Heyu software to communicate with the X10 modules through the CM11A serial adapter module. I have an X10 Lamp Module that automatically lights up when someone walks by the home security system's motion detector (also connected to the RaspberryPi), and I have an X10 Appliance Module that kills power to home entertainment system. Originally I wanted to control the power to some computer systems, but the power supplies in the computer systems then introduce too much noise to get a response from the X10 modules.

See also: label:x10, Omnia:X10, Omnia:heyu