embedded system,arduino,raspberry pi,msp430f169, ARM7

Friday, January 24, 2014

On 11:03 PM by array operation   No comments
raspberry pi with l293d driver with controlling with two motors.

l293d motor driver ic will control the
1.4 motor in 1-direction
2.2motors in 2-directions

we need the triggering only...
4gpio pins of the raspberry pi






for more info  and components please visit



Tuesday, January 21, 2014

On 3:55 AM by array operation   1 comment
PIR motion sensors
PIR sensors allow you to sense motion, almost always used to detect whether a human has moved in or out of the sensors range. They are small, inexpensive, low-power, easy to use and don't wear out. For that reason they are commonly found in appliances and gadgets used in homes or businesses. They are often referred to as PIR, "Passive Infrared", "Pyroelectric", or "IR motion" sensors.
PIRs are basically made of a pyroelectric sensor (which you can see above as the round metal can with a rectangular crystal in the center), which can detect levels of infrared radiation. Everything emits some low level radiation, and the hotter something is, the more radiation is emitted. The sensor in a motion detector is actually split in two halves. The reason for that is that we are looking to detect motion (change) not average IR levels. The two halves are wired up so that they cancel each other out. If one half sees more or less IR radiation than the other, the output will swing high or low.
Along with the pyroelectic sensor is a bunch of supporting circuitry, resistors and capacitors. It seems that most small hobbyist sensors use the BISS0001 ("Micro Power PIR Motion Detector IC") , undoubtedly a very inexpensive chip. This chip takes the output of the sensor and does some minor processing on it to emit a digital output pulse from the analog sensor.
For many basic projects or products that need to detect when a person has left or entered the area, or has approached, PIR sensors are great. They are low power and low cost, pretty rugged, have a wide lens range, and are easy to interface with. Note that PIRs won't tell you how many people are around or how close they are to the sensor, the lens is often fixed to a certain sweep and distance (although it can be hacked somewhere) and they are also sometimes set off by housepets. Experimentation is key!
These stats are for the PIR sensor in the Adafruit shop which is very much like the Parallax one . Nearly all PIRs will have slightly different specifications, although they all pretty much work the same. If there's a datasheet, you'll want to refer to it
·         Size: Rectangular
·         Price: $10.00 at the Adafruit shop
·         Output: Digital pulse high (3V) when triggered (motion detected) digital low when idle (no motion detected). Pulse lengths are determined by resistors and capacitors on the PCB and differ from sensor to sensor.
·         Sensitivity range: up to 20 feet (6 meters) 110° x 70° detection range
·         Power supply: 5V-9V input voltage,
·         BIS0001 Datasheet (the decoder chip used)
·         RE200B datasheet (most likely the PIR sensing element used)
·         NL11NH datasheet (equivalent lens used)
More links!
·         NYU sensor report
PIR sensors are more complicated than many of the other sensors explained in these tutorials (like photocells, FSRs and tilt switches) because there are multiple variables that affect the sensors input and output. To begin explaining how a basic sensor works, we'll use this rather nice diagram (if anyone knows where it originates plz let me know).
The PIR sensor itself has two slots in it, each slot is made of a special material that is sensitive to IR. The lens used here is not really doing much and so we see that the two slots can 'see' out past some distance (basically the sensitivity of the sensor). When the sensor is idle, both slots detect the same amount of IR, the ambient amount radiated from the room or walls or outdoors. When a warm body like a human or animal passes by, it first intercepts one half of the PIR sensor, which causes a positive differential change between the two halves. When the warm body leaves the sensing area, the reverse happens, whereby the sensor generates a negative differential change. These change pulses are what is detected.

[Citation needed]
The IR sensor itself is housed in a hermetically sealed metal can to improve noise/temperature/humidity immunity. There is a window made of IR-transmissive material (typically coated silicon since that is very easy to come by) that protects the sensing element. Behind the window are the two balanced sensors.
You can see above the diagram showing the element window, the two pieces of sensing material
This image shows the internal schematic. There is actually a JFET inside (a type of transistor) which is very low-noise and buffers the extremely high impedence of the sensors into something a low-cost chip (like the BIS0001) can sense.
PIR sensors are rather generic and for the most part vary only in price and sensitivity. Most of the real magic happens with the optics. This is a pretty good idea for manufacturing: the PIR sensor and circuitry is fixed and costs a few dollars. The lens costs only a few cents and can change the breadth, range, sensing pattern, very easily.
In the diagram up top, the lens is just a piece of plastic, but that means that the detection area is just two rectangles. Usually we'd like to have a detection area that is much larger. To do that, we use a simple lens such as those found in a camera: they condenses a large area (such as a landscape) into a small one (on film or a CCD sensor). For reasons that will be apparent soon, we would like to make the PIR lenses small and thin and moldable from cheap plastic, even though it may add distortion. For this reason the sensors are actually Fresnel lenses :
The Fresnel lens condenses light, providing a larger range of IR to the sensor.
OK, so now we have a much larger range. However, remember that we actually have two sensors, and more importantly we dont want two really big sensing-area rectangles, but rather a scattering of multiple small areas. So what we do is split up the lens into multiple section, each section of which is a fresnel lens

Here you can see the multiple facet-sections

This macro shot shows the different Frenel lenses in each facet!
The different faceting and sub-lenses create a range of detection areas, interleaved with each other. Thats why the lens centers in the facets above are 'inconsistant' - every other one points to a different half of the PIR sensing element
Here is another image, more qualitative but not as quantitative. (Note that the sensor in the Adafruit shop is 110° not 90°)
Most PIR modules have a 3-pin connection at the side or bottom. The pinout may vary between modules so triple-check the pinout! It's often silkscreened on right next to the connection. One pin will be ground, another will be signal and the final one will be power. Power is usually 3-5VDC input but may be as high as 12V. Sometimes larger modules dont have direct output and instead just operate a relay in which case there is ground, power and the two switch connections.
The output of some relays may be 'open collector' - that means it requires a pullup resistor. If you're not getting a variable output be sure to try attaching a 10K pullup between the signal and power pins.
An easy way of prototyping with PIR sensors is to connect it to a breadboard since the connection port is 0.1" spacing. Some PIRs come with header on them already, the ones from Adafruit don't as usually the header is useless to plug into a breadboard.
By soldering in 0.1" right angle header, a PIR is easily installed into a breadboard!
Most people want to position PIRs in a particular location and often times thats far from the other electronics, in which case wires will work just fine.
Once you have your PIR wired up its a good idea to do a simple test to verify that it works the way you expect. This test is also good for range testing. Simply connect 3-4 alkaline batteries (make sure you have more than 3.5VDC out but less than 6V by checking with your multimeter!) and connect ground to the - pin on your PIR. Power goes to the + pin. Then connect a basic red LED (red LEDs have lower forward voltages than green or blue so they work better with only the 3.3v output) and a 220Ω resistor (any value from 100Ω to 1.0KΩ will do fine) to the out pin as shown. Of course, the LED and resistor can swap locations as long as the LED is oriented connection and connects between out and ground
Now when the PIR detects motion, the output pin will go "high" to 3.3V and light up the LED!
Once you have the breadboard wired up, insert batteries and wait 30-60 seconds for the PIR to 'stabilize'. During that time the LED may blink a little. Wait until the LED is off and then move around in front of it, waving a hand, etc, to see the LED light up!
Once you have the LED blinking, look on the back of the PIR sensor and make sure that the jumper is placed in the L position as shown above.
Now set up the testing board again. You may notice that when connecting up the PIR sensor as above, the LED does not stay on when moving in front of it but actually turns on and off every second or so. That is called "non-retriggering".
Now change the jumper so that it is in the H position. If you set up the test, you will notice that now the LED does stay on the entire time that something is moving. That is called "retriggering"
http://www.ladyada.net/wiki/lib/exe/fetch.php?hash=68a81d&w=550&h=219&media=http%3A%2F%2Fwww.ladyada.net%2Fimages%2Fsensors%2Fretriggerable.gif
(The graphs above are from the BISS0001 datasheet, they kinda suck)
For most applications, "retriggering" (jumper in H position) mode is a little nicer. If you need to connect the sensor to something edge-triggered, you'll want to set it to "non-retriggering" (jumper in L position).
There are two 'timeouts' associated with the PIR sensor. One is the "Tx" timeout: how long the LED is lit after it detects movement. The second is the "Ti" timeout which is how long the LED is guaranteed to be off when there is no movement. These are not easily changed but if you're handy with a soldering iron it is within reason.
First, lets take a look at the BISS datasheet again
Determining R10 and R9 isnt too tough. Unfortunately this PIR sensor is mislabeled (it looks like they swapped R9 R17). You can trace the pins by looking at the BISS001 datasheet and figuring out what pins they are - R10 connects to pin 3 and R9 connects to pin 7. the capacitors are a little tougher to determine, but you can 'reverse engineer' them from timing the sensor and solving!
For the sensor in the Adafruit shop:
Tx is = 24576 * R10 * C6 = ~1.2 seconds 
R10 = 4.7K and C6 = 10nF
Likewise,
Ti = 24 * R9 * C7 = ~1.2 seconds 
R9 = 470K and C7 = 0.1uF
You can change the timing by swapping different resistors or capacitors.

for documentation of the pir 
please click HERE


On 3:51 AM by array operation   No comments
This is the post explain about the how to connect the raspberry pi with motion sensor(PIR)

Hardware required
1.raspberry pi
2.pir sensor
3.jumper wires

connections:
pir sensor having 3 pin back side of it

1.VCC(5v)
2.output(which is 3.3v output...connected to raspberry pi)
3.GND




take a new file using  
sudo nano pir_test.py
program:

#!/usr/bin/python
#+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
#|potentiallabs.com
#+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
#
# pir_1.py
# Detect movement using a PIR module
#
# Author : anil durgam
# Date   : 21/01/2014

# Import required Python libraries
import RPi.GPIO as GPIO
import time

# Use BCM GPIO references
# instead of physical pin numbers
GPIO.setmode(GPIO.BCM)

# Define GPIO to use on Pi
GPIO_PIR = 7

print "PIR Module Test (CTRL-C to exit)"

# Set pin as input
GPIO.setup(GPIO_PIR,GPIO.IN)      # Echo

Current_State  = 0
Previous_State = 0

try:

  print "Waiting for PIR to settle ..."

  # Loop until PIR output is 0
  while GPIO.input(GPIO_PIR)==1:
    Current_State  = 0

  print "  Ready"

  # Loop until users quits with CTRL-C
  while True :

    # Read PIR state
    Current_State = GPIO.input(GPIO_PIR)

    if Current_State==1 and Previous_State==0:
      # PIR is triggered
      print "  Motion detected!"
      # Record previous state
      Previous_State=1
    elif Current_State==0 and Previous_State==1:
      # PIR has returned to ready state
      print "  Ready"
      Previous_State=0

    # Wait for 10 milliseconds
    time.sleep(0.01)

except KeyboardInterrupt:
  print "  Quit"
  # Reset GPIO settings
  GPIO.cleanup()

compiling this code
sudo python pir_test.py


after compilation of the output look like this



Friday, January 17, 2014

On 5:46 AM by array operation   1 comment
Web browser based controlling the raspberry pi.(webiopi)

for this 1 we need the some installation steps
1.open the raspberry pi  command mode
2.and install below commands
              $ wget http://webiopi.googlecode.com/files/WebIOPi-0.6.0.tar.gz
              $ tar xvzf WebIOPi-0.6.0.tar.gz
              $ cd WebIOPi-0.6.0
              $ sudo ./setup.sh

Running WebIOPi

for installation is done the  give this command

sudo webiopi -d -c /etc/webiopi/config

Running WebIOPi

start the webiopi give this command
$ sudo /etc/init.d/webiopi start

stop the webiopi give this command
$ sudo /etc/init.d/webiopi stop

start at boot

To setup your system to start webiopi at boot :

$ sudo update-rc.d webiopi defaults

To remove webiopi start from boot :

$ sudo update-rc.d webiopi remove

Controlling from the web browser

If your are directly using your Raspberry Pi with keyboard/mouse/display plugged, open a browser to http://localhost:8000/



If your Raspberry Pi is connected to your network, you can open a browser to http://raspberrypi:8000/ with any device of your network. Replace raspberrypi by its IP.

You can even add a port redirection on your router to use WebIOPi over Internet !

Default user is "webiopi" and password is "raspberry"

By choosing the GPIO Header link on the main page, you will be able to control GPIO using a web UI which looks like the board header.

Click/Tap the OUT/IN button to change GPIO direction.
Click/Tap pins to change the GPIO output state.







On 4:59 AM by array operation   No comments
Course Contents

Introduction

*      Introduction to Embedded Systems
*      Introduction to ATMega328 on Arduino Board
*      Kit Contents Overview
*      Arduino IDE & Driver Installation
*      Arduino Board Overview
*      Program Structure Overview
*      Working with Digital Outputs
*      Working with Analog Outputs

 Digital I/O's

*      Introduction to Digital Inputs  and Outputs
*      Working with LEDs and Switches
*      Building a Simple Switch Controlled Binary Counter
*      Working with Serial Communication
*      Controlling the Binary Counter through a Serial Interface

Analog I/O's

*      Working with Analog Inputs – LDR [Light Sensor]
--Building A Simple LDR based Lighting Level Controller
*      Working with Analog Inputs – LM35 [Temperature Sensor]
--Building A Simple LM-35 based Room temperature displaying on Serial Monitor
*      Working with Analog Outputs – PWM techniques
--controlling the motors

Advanced I/O Operations & Displays 

*        Working with Liquid Crystal Displays(LCDs)
*      Advanced I/O Operations - Driving a 7-Segment Display
*      Displaying Temperature using two 7-Segment Display
*      Dot matrix Display






IR Communication

*      Distance Sensing and Working with Ultrasonic Sensor
*      Introduction to Communication Protocols - IR Remotes
*      Controlling LEDs with a TV remote
*      Building a IR Based Communication System
-- Building a simple IR based counting machine

I2C Communication

*      Introduction to I2C Communication
*      Working with I2C Communication - RTC - DS1307
*      Build a Simple LCD Clock
*      Build a Simple Timer Controlled Lighting System

Interrupts & Motor Control

*      Working with Interrupts
*      Working with Motor Drivers – H-bridges
*      Working with DC Motors
*      Working with Stepper Motors
*      Working with Servo Motors
*      Building a Remote Control Based Motor Speed Controller


Advanced Serial Communication Devices

*       Basic Power Regulation Circuitry
*      Breadboard Construction of Micro-controller Circuitry
*      ]Interfacing RFID - Reading Tags and comparing
*      Zigbee - Bidirectional Wireless Communication

download this HERE