Tag Archives: IOT

IOT Survillance with Arduino + Rpi + WebRTC

“ The Internet of Things (IoT) is the network of physical objects or “things” embedded with electronics, software, sensors and connectivity to enable it to achieve greater value and service by exchanging data with the manufacturer, operator and/or other connected devices. “ – wikipedia

Smart TV , mobiles , CCTV cams and other few things are already connected to the Internet.So whether we’ve known it or not, the “Internet of Things” is already here. But , number of these interconnections is on the rise and need to controlled , monitored and optimized .

IOT areas where media streaming capabilities of

  • Home automation
  • Targeted marketing
  • Wildlife and environment
  • Manufacturing
  • Smart Grid /  real-time energy optimization.
  • Connected logistics
  • Augmented reality
  • Ubiquitous computing (ubicomp) / BYOD
  • Healthcare
  • Transportation / connected car

This post describes the process of creating a Arduino based IOT control setup over Internet. The features of this application are

  1. Cheap and more customized solution to specific use cases
  2. Recycled components
  3. No patented or proprietary protocols
  4. Easy person-to-machine and machine-to-machine comm.
  5. Can be integrated with other modules like Recording , Multiplexing , transcoding .

Requirements :

Hardware requirements

  1. Rpi as communication hub to internet
  2. ultrasonic sensors to detect obstruction in field of view
  3. camera module of Rpi or standrad webcam
  4. Motion Sensors
  5. Buzzer
  6. mic
  7. flash lights connected via relay drivers to rpi

Software requirements

  1. open CV ( image processing)
  2. Simple CV ( face recognition )
  3. motion
  4. webrtc for media live streaming in case of remote monitoring

 

Screenshot from 2015-11-10 22:02:25

Screenshot from 2015-11-11 11:22:09

WebRTC communication and media streaming setup

Screenshot from 2015-11-11 11:31:30

Raspberry Pi Communication Modules

 

Ethernet

Ethernet wires can connect rpi to a another machine such as  laptop  from which it can be connected via terminal or using remote desktop accessing software’s such as tightvnc .

ethernet

Undoubtedly Ethernet offers the fastest speed, lowest latency and no  data loss due to wireless interference problems however it is as the price of being immobile , as its is a wired connection and shifting disrupts the connection .

Cat-5e cable and  Cat-6e cable can offer upto  1 Gb/s and  10 Gb/s respecctively .

Wifi or IEEE 802.11  wifi

Wi-Fi was launched in the year 1997. Victor Hayes is known as father of Wi-Fi.

There are various standards and adoptions for IEEE802.11 like 802.11ac, 802.11n, 802.11g, and 802.11b which can offer maximum speeds of 866.7 Mbit/s , 150 Mbit/s  ,  54 Mbit/s and 11 Mbit/s respectively , however consumes more power than Bluetoooth .

Image Wifi hotspot

wifi

Image Wifi USB

wifi2

Image Wifi module Rpi

Wifi -direct can even reach upto 250mbps of data transferring rate at  2.4, 3.6 and 5 GHz frequency . Range is around 100m .

BLE / Bluetooth ble

Bleutooth was launched in 1994 as a wireless communication alternative to RS232 by  Ericsson . Now it is handled by Special Interest group  for Bluetooth.

ble

Bluetooth 4.0 can do data transfer rates to be upto 25mbps  at 2.4GHz frequency  while maximum range being 30 m .

GSM / GPRS

This section refers to the data provider by the network of a telecom carrier company such as Airtel , Tata Docomo etc in India . 2G capabilities

gsm

Majorly the technology behind the differnt generation of telecom is as follows
2G – GSM 900, GSM 1800 – 14.4 kbps
3G – UMTS 2100 – 3.1 Mbps
4G – LTE 850 (5), LTE 1800 (3), LTE 2300 (40) – 100 Mbps

The carries frquency varries from 200 KH , 5 MHz , 15 MHz recpectively

NFC

Short for Near Field Communication . NFC uses electromagnetic induction between two loop antennae in smart devices to exchange information.
It uses unlicensed radio frequency ISM band of 13.56 MHz with data trabsfer rate of about 106 to 424 kbit/s.Unlike bluetooth it is a point to point communication .

Audio / Video Streaming

First enable the rpi camera support from the boot screen

rpi_camera._support

One can choose between the following ways to be able to stream data from a Rpi

  1. Motion

To start motion detection edit motion.cong file

$ vi /etc/motion/motion.conf

Although the it starts detecting motion automatically we can modify few properties like

# Threshold for number of changed pixels in an image that
# triggers motion detection (default: 1500)
threshold 1500
# Detect motion in predefined areas (1 – 9). Areas are numbered like that: 1 2 3
# A script (on_area_detected) is started immediately when motion is 4 5 6
# detected in one of the given areas, but only once during an event. 7 8 9
# One or more areas can be specified with this option. Take care: This option
# does NOT restrict detection to these areas! (Default: not defined)
; area_detect value

# Picture frames must contain motion at least the specified number of frames
# in a row before they are detected as true motion. At the default of 1, all
# motion is detected. Valid range: 1 to thousands, recommended 1-5
minimum_motion_frames 1

# Specifies the number of pre-captured (buffered) pictures from before motion
# was detected that will be output at motion detection.
# Recommended range: 0 to 5 (default: 0)
# Do not use large values! Large values will cause Motion to skip video frames and
# cause unsmooth movies. To smooth movies use larger values of post_capture instead.
pre_capture 10

# Number of frames to capture after motion is no longer detected (default: 0)
post_capture 10

# Event Gap is the seconds of no motion detection that triggers the end of an event.
# An event is defined as a series of motion images taken within a short timeframe.
# Recommended value is 60 seconds (Default). The value -1 is allowed and disables
# events causing all Motion to be written to one single movie file and no pre_capture.
# If set to 0, motion is running in gapless mode. Movies don’t have gaps anymore. An
# event ends right after no more motion is detected and post_capture is over.
event_gap 60

# Maximum length in seconds of a movie
# When value is exceeded a new movie file is created. (Default: 0 = infinite)
#max_movie_time 0
max_mpeg_time 240

# Always save images even if there was no motion (default: off)
emulate_motion off
To beep when motion is detected
Note: Motion never beeps when running in daemon mode.
quiet off

To draw a identifiable area where motion is deceted
# Set the look and style of the locate box if enabled.
# Valid values: box, redbox, cross, redcross (default: box)
# Set to ‘box’ will draw the traditional box.
# Set to ‘redbox’ will draw a red box.
# Set to ‘cross’ will draw a little cross to mark center.

locate_motion_style box

 

2.WebRTC ( rpi model 2 onwards)

In terminal:

$ curl http://www.linux-projects.org/listing/uv4l_repo/lrkey.asc | sudo apt-key add -
add this to /etc/apt/sources.list : 
deb http://www.linux-projects.org/listing/uv4l_repo/raspbian/ wheezy main 

or simply run

wget http://www.linux-projects.org/listing/uv4l_repo/lrkey.asc && sudo apt-key add ./lrkey.asc

linuxProject

Update the repos

 $ sudo apt-get update

Now install uv4l and supported software

 $ sudo apt-get install uv4l uv4l-raspicam

If you want the driver to be loaded at boot, also install this optional package:

 $ sudo apt-get install uv4l-raspicam-extras

 

Most importantly install the uv4l server and the WebRTC extension for the Streaming Server

 $ sudo apt-get install uv4l-webrtc

Screenshot from 2016-06-19 15-24-00

Type uv4l –help for getting  list of options for core , streaming , fine tuning , logging etc

start the service using following command


sudo service uv4l_raspicam start

Screenshot from 2016-06-19 15-41-10

Open web
http://<rpi ip address>:8080/conference

Screenshot from 2016-06-19 15-41-34

Once the media capture and stream is established it is important to decide the stream methodology such as relay through a centralized media server or mesh streaming network as in webrtc p2p.

Click on any of the given options to see a incoming media stream from rpi

For example

Webrtc :

http://<rpi_ip&gt;:8080/stream/webrtc  gives incoming Webrtc media stream.

MJpeg

http://<rpi_ip&gt;:8080/stream/video.mjpeg gives mjpeg

 

The default server config is

  • basic HTTP/HTTPS authentication: disabled
  • underlying video device node: /dev/video0
  • current connections: 1, queued: 0, total handled: 11
  • max. simultaneous streams allowed: 3, max. threads: 5
  • raw HTTP/HTTPS video streams in MJPEG, JPEG (continuous stills) and H264 formats – if supported – are available under the /stream/video.mjpeg, /stream/video.jpeg, and /stream/video.h264URL paths respectively

Note : https is required if you want to have a outgoing video from your computer to rpi as browser mandates secure origin but https is not required for an incoming video stream so you can easily view the rpi genrated webrtc video without being on https .


 

Advertisements

Bluetooth Low Energy on Adafruit Arduino

Lately as I develop and realize few IOT use-cases , I have concluded that BLE ( Bluetooth Low Energy) , also known as Bluetooth smart , is a very good choice as it runs for longer periods of time with smaller power sources.

What is BLE ?

This is the version 4.0+ of Bluetooth which is aimed as building the communication network for IOT ( Internet of things ) . Like classic Bluetooth it utilizes the 2.4 Ghz band and performs in dual-mode. Also both the models use Gaussian frequency shift modulation for data transmission.

How is BLE different from classic Bluetooth ?

Power and Life : BLE provided better bit rate with lesser power consumption( 0.01W to 0.1W) than classic bluetooth technology ( 1 W). Channel : While Classic Bluetooth uses 79 1-MHz channels , BLE has 40 2-MHz channels

How can one make use of BLE in IOT ?

If you have a usecase that needs implementation than high changes are it needs 3 basic components: 1. End devices such as machines , automated doors , surveillance systems , metering systems etc This is where BLE can be used to transmit realtime data quickly to central controller

  1. Central control hub to control the end points and communicate to server This has to be a bridge between BLE devices and internet to put all the gathered information on the cloud for analysis and logic processing.
  2. User provisioning system or Graphical interface to who stats , status , control options etc . This is also a critical component as the user needs to have a way of controlling the operation without physically going to the machines . Although the system can very much work without given a pre-programmed operation .

*References *

you can learn more about bluetooth form these links


Simple Adafruit Bluefruit Bluetooth LE UART android app

This is the first and the most basic example of using BLE.

Code

Key concepts for BLE programming

GATT ( Generic Attribute Profile) : The bluetooth Special Interest Group ( SIG ) defines many profile for low energy devices.  GATT is also an profile for sending and receiving short data in low energy devices .

ATT (Attribute Protocol ) : Each attribute is uniquely identified by a Universally Unique Identifier (UUID), which is a standardized 128-bit format for a string ID. The attributes transported by ATT are formatted as characteristics and services

BLE activity class

While defining the Bluetooth LE UART acttivity class we must extend the BluetoothGattCallback parent class and implement the BluetoothAdapter.LeScanCallback interface .

Then define the public data values for the device such as UUID of the UART , TX and RX. Also the UUID for the UART BTLE client characteristic which is necessary for notifications .UUIDs for the Device Information service and associated characeristics such as Manufacture , Model , hardware , software .

set the adapter to BluetoothAdapter.getDefaultAdapter()

we can define some callbacks in an interface , This enables BLE UART client to be notified of UART actions .

 public interface Callback {
 public void onConnected(BluetoothLeUart uart);
 public void onConnectFailed(BluetoothLeUart uart);
 public void onDisconnected(BluetoothLeUart uart);
 public void onReceive(BluetoothLeUart uart, BluetoothGattCharacteristic rx);
 public void onDeviceFound(BluetoothDevice device);
 public void onDeviceInfoAvailable();
 }

For scanning the available devices , call adapter.startLeScan(this) . This will Start scanning for BLE UART devices. Registered callback’s onDeviceFound method will be called when devices are found during scanning. Similarly call adapter.stopLeScan(this) to stop the device scan .

we may also define Handlers for BluetoothGatt and LeScan events such as ,

1. onLeScan

Stop if the device doesn’t have the UART service

        if (!parseUUIDs(scanRecord).contains(UART_UUID)) {
            return;
        }

Notify registered callbacks of found device.

        notifyOnDeviceFound(device);

connect to device

	gatt = device.connectGatt(context, true, this);

2. onConnectionStateChange

super.onConnectionStateChange(gatt, status, newState);

we can check the state through BluetoothGatt.STATE_CONNECTED and status of connection through BluetoothGatt.GATT_SUCCESS.
Further more we can check if the service was found on the device through gatt.discoverServices()
If any of the above conndition were not checked we can call connectFailure() which signifies that connection was a failure and reset cinnection state through

        rx = null;
        tx = null;
        notifyOnConnectFailed(this);

Simillarlily if state was BluetoothGatt.STATE_DISCONNECTED then notify callbacks of disconnection.
3. onServicesDiscovered
super.onServicesDiscovered(gatt, status);

notify connection failure if service discivery failed

status == BluetoothGatt.GATT_FAILURE

Save reference to each UART characteristic.

        tx = gatt.getService(UART_UUID).getCharacteristic(TX_UUID);
        rx = gatt.getService(UART_UUID).getCharacteristic(RX_UUID);

Save reference to each DIS characteristic.

        disManuf = gatt.getService(DIS_UUID).getCharacteristic(DIS_MANUF_UUID);
        disModel = gatt.getService(DIS_UUID).getCharacteristic(DIS_MODEL_UUID);
        disHWRev = gatt.getService(DIS_UUID).getCharacteristic(DIS_HWREV_UUID);
        disSWRev = gatt.getService(DIS_UUID).getCharacteristic(DIS_SWREV_UUID);

Add device information characteristics to the read queue . These need to be queued because we have to wait for the response to the first read request before a second one can be processed

        readQueue.offer(disManuf);
        readQueue.offer(disModel);
        readQueue.offer(disHWRev);
        readQueue.offer(disSWRev);

Request a dummy read to get the device information queue going

        gatt.readCharacteristic(disManuf);

Setup notifications on RX characteristic changes (i.e. data received).

First call setCharacteristicNotification to enable notification

gatt.setCharacteristicNotification(rx, true)

Stop if the characteristic notification setup failed.

Next update the RX characteristic’s client descriptor to enable notifications

BluetoothGattDescriptor desc = rx.getDescriptor(CLIENT_UUID)
desc.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
gatt.writeDescriptor(desc)

Stop if the RX characteristic desc has no client descriptor ie null or if the client descriptor could not be written.

Notify of connection completion.

        notifyOnConnected(this);

3. onCharacteristicChanged

        super.onCharacteristicChanged(gatt, characteristic);
        notifyOnReceive(this, characteristic);

4. onCharacteristicRead

	super.onCharacteristicRead(gatt, characteristic, status);

Check if there is anything left in the queue

            BluetoothGattCharacteristic nextRequest = readQueue.poll();

if nextRequest is not null ie it has items more Send a read request for the next item in the queue

                gatt.readCharacteristic(nextRequest);

else We’ve reached the end of the queue so set the flags and make the callback

                disAvailable = true;
                notifyOnDeviceInfoAvailable();

5. onCharacteristicWrite

	super.onCharacteristicWrite(gatt, characteristic, status);

android manifest file

1. Declare the Bluetooth permission to perform connection and data transfer over bluetooth

<uses-permission android:name=”android.permission.BLUETOOTH”/>

2. To initiate device discovery or manipulate Bluetooth settings, you must also declare the BLUETOOTH_ADMIN permission.

<uses-permission android:name=”android.permission.BLUETOOTH_ADMIN”/>

3. To declare that your app is available to BLE-capable devices only.

<uses-feature android:name=”android.hardware.bluetooth_le” android:required=”true”/>

Layout

Android studio screenshots 

I have used Adafruit Bluefruit LE UART Friend – Bluetooth Low Energy (BLE) device . More details about this can be found here .

The circuit for a BLE Arduino is as follows :

This application has more modules than the previous simple read and write application . It can work in 4 modes namely

  1. Info
  2. UART
  3. Controller
  4. Beacon

The circuit arrangement is shown in following pictures :

The edited source code of the android application is on the github repo : https://github.com/DKAagri/BluefruitArduinoLE

screenshots of the Android application

The controller mode

ColorPickerActivity

We can connect a android phone in adb mode to android studio and monitor the realtime network , memory and other stats.

See the connection and communication entities form the android device monitor logcat

The code of this application is derived from

https://github.com/adafruit/Bluefruit_LE_Connect_Android

More information about Bluefruit LE the device can be obtained form

https://blog.adafruit.com/2014/11/19/new-products-bluefruit-le-friend-bluetooth-low-energy-ble-4-0-nrf51822-v1-0-bluefruit-le-sniffer-bluetooth-low-energy-ble-4-0-nrf51822-v1-0/

Remote machine control via Rpi

Raspberry pi

The Raspberry Pi is a series of credit card-sized single-board computers. It can be used to build hardware along with software system . It essentially acts like a mini computer where we can install our programs and work on them pretty much like a regular computer . However the applications of Rpi is really diversifies from making robots to kiosks , surveillance system to remote control agents etc .

Yes the new model B+ is out yet I have an old B model and I am trying ot most of the things using it before making the investment of purchasing a  new one .

2 3(images from : http://www.adafruit.com/products/998)

Configuration :

  • The design is based around a Broadcom BCM2835 SoC, which includes an ARM1176JZF-S 700 MHz processor, VideoCore IV GPU, and 512 Megabytes of RAM.
  • The design does not include a built-in hard disk or solid-state drive, instead relying on an SD card for booting and long-term storage.
  • This board is intended to run Linux kernel based operating systems.
  • Generic USB keyboards and mice are compatible with it .
  • It does not come with a real-time clock, so an OS must use a network time server, or ask the user for time information at boot time to get access to time and date info for file time and date stamping. However a real time clock (such as the DS1307) with battery backup can be easily added via the I2C interface.

Physical architecture :

rpib

Pin Model :

p1header

Rpi model B startup

Requirements for boot

  1. Power supply
  2. HDMI cable to connect to HDMI tv or HDMI to VGA adapterto connect to monitor
  3. power charger ( micro USB same as phone )
  4. SD card upto 8 GB ( in case its a micro SD card then SD card adpater as well)
  5. monitor
  6. keyboard
  7. mouse
  8. internet through ethernet
  9. ethernet wire

Steps:

top view of the board

top view of the board

HDMI connector for screen display from Rpi

HDMI connector for screen display from Rpi

NOOBS

NOOBS

Raspbian start

Raspbian start

rpi5 rpi6 rpi8 rpi9

Default id : pi  default password : raspberry

Default id : pi
default password : raspberry

OS boot up

OS boot up

rpi12

raspbian on Raspberry pi

raspbian on Raspberry pi

run sudo apt-get update

run sudo apt-get update


 RPI model B to LED glow using timers in python

Aim :

First time booting Raspbian on Raspberry pi Model B . Connecting it to LED ( series with resistor ) and controlling the on -off process using timer logic written in python .

Requirements :

  1. Rs(RaspberryPi)
  2. Power supply
  3. Ethernet wire(3m)
  4. SDcard or micro SD card with adpater
  5. Breadboard
  6. LED(7)
  7. resistors(1k )(7)
  8. button
  9. breadboard wires

Steps :

1. Manual ON and OFF of LED on Rpi GPIO

To manually make the LED turn ON and OFF ,  make a serial connection of two GPIO pins with a LED  and resistor ( shown in the picture )

rpi15

  • Open terminal and sudo su  to :/home/pi#
  • #echo25>/sys/class/gpio/export
  • File manager -> /home/pi -> sys -> class ->gpio -> gpiochip0 -> device -> gpio ->gpio25 , Change directory to this location
  • #cd /sys/class/gpio/gpiochip0/device/gpio/gpio25
  • List all files , with gpio#ls

To give output to LED through the pin 25 :

  • echo out>direction ( set this pin as output)
  • To tuen ON the LED , write 1 to the value of pin echo 1> value

To take input through pin 24 through a button

  • connect button to pin 24 of Rpi as earlier
  • echo in >direction
  • see the changes on pressing the button on cat value

2. GPIO control with WiringPi library

  • Install git , sudo apt-get innstall git-core
  • Get the sourcecode with :sudo git clone git://git.drogon.net/wiringpi
  • cd wiringPi
  • ./build
  • $gpio -v
  • $gpio readall

To turn ON or OFF the first LED wiring pin 0 , set the pin as an output  -> gpio mode 0 out

  • To turn ON LED  -> $gpio write 0 1
  • To turn OFF  -> $gpio write 0 0

To read from a digital switch on wiringPin no

  • $ gpio read 0

Applications:

1.  Timer based control

Following are the steps to make and execute a LED  control using timers in python .


 Machine control through RPi via Mobile app on Internet

Aim :

Controlling a machine via Rpi hub connected to internet . Users can control machine behavior through a web page or mobile app .

Steps:

1. Install Raspbian wheezy ( details of installation are provided in the 1fisrt application on this page )

2. Get win32 Disk-manager 0.25 and dump into raspberry

3. Connect the Rpi via Ethernet wire to internet router . Find IP address of Rpi client by checking the router default console .

4. Connect the Rpi to remote machine

For Linux remote machine OS –Install tightVNC server

  • ssh  raspberrypi_username@ipaddress
  • sudo apt-get updates
  • sudo apt-get install tightvncserver
  • During installation supply a username and password example , username pi  , password altanai.

The viewer for VNC could be Remmina VNC viewer on linux

  • Incoming VNC server .
  • Enter username and password

For Windows  remote machine OS –Install putty

  • Enter Rpi_ip:port
  • login as pi given password  for example altanai

5. For the webpage

  • Install a web server  :sudo apt-get install apache2 php5 libapache2-mod-php5
  • transfer the web page for machine control  to Rpi inside /var/www
  • index.phpo :  <?php phpinfo(); ?>
  • ctrl+ o to save , ctrl + x to exit
  • change permission fr user pi :  chown -R pi /var/www
  • test the webpage at http://rpi_address

6. For the android app

7. To control real machine like fan , tubelight , washing machine  , connect the output of Rpi to relay.

8. To control the machines from anywhere on the internet , this page need to be on public DNS . There fore host the website on public server like amazon Ec2 instance .

Light Fan control Rpi web

 


Ref :

  1. http://www.adafruit.com/products/998
  2. http://www.raspberrypi.org/
  3. http://www.instructables.com/id/Simple-and-intuitive-web-interface-for-your-Raspbe/