Month: July 2012

PiScanner | Project Execution [Demonstration/Distribution]

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I should preface this by saying that it is no where near as polished as it could be. But it works, and the objects taken by the camera are recognizable. Eventually, if I have the funding, I will upgrade the Camera.

There are many elements to this project. There really isn’t a great place to start with this project, so well start with the fritzing schematic and a list of materials needed.

You will need:

2 Attiny85’s
16 wires
a breadboard
a 100k ohm resistor
a 330 ohm resistor
a raspberry pi
PIR motion detector
the cables for interfacing with the raspberry pi
an isp programmer for the attiny’s

So let’s look at this schematic:

When motion is detected, the signal pin on the motion detector gets pulled low. at this point the 3.3v attiny pulls pin 1 high, sending a signal into the rpi (it’s 3.3v so it’s safe for the broadcomm) and illuminating an LED so the user can see that motion is being detected.

The raspberry pi then sends a signal to the 5v attiny indicating that motion has indeed been detected. Once this occurs, the 5v attiny pulls the 5v pin going to the webcam high. I had to integrate this step of turning the webcam on via the attiny because there is a hardware misconfiguration that causes the software i’m using to take the picture hang. Turning the camera off and on each time a picture needs to be taken gets rid of this problem, because the camera always takes the first picture after being turned on.

At this point a picture is taken and moved to a flash drive. They could be moved wherever, but a flashdrive works the best for now, as I will be deploying this system in a place where there isn’t internet (in my garage)

Now time for source codes!

Software wise you will need:

The Arduino IDE

Python (I’m using Geany on the raspberry pi)

fswebcam which you can obtain by running

On your raspberry pi.

This is the source for the 3.3v attiny85

This is the source for the 5v attiny85

This is the python source, you will need to install this to make it work though.

This is the Fritzing document.

Here’s a sample image from the camera. It is looking at the breadboard.

Hey! This post was written a long time ago, but I'm leaving it up on the off-chance it may help someone. Proceed with caution. It may not be a good idea to blindly integrate this code or work into your project, but instead use it as a starting point.

PiScanner – GPIO output | Documentation [Research]

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I will need to illuminate the “subjects” that I will be capturing. In order to do this, I will eventually need to set some pin high. Weather it be that it sets of a camera flash or turns on some lights for a second, it will need to happen down the line.

 

Like all of my “research” I mostly googled around / plugged in code until something worked. I came back with these links:

http://www.youtube.com/watch?v=q_NvDTZIaS4

https://docs.google.com/file/d/0B2-00drKdqF0V09YSHgxcTEtelk/edit

http://hackaday.com/2012/06/17/using-the-gpio-pins-on-a-raspberry-pi/

 

Basically you need to install the Raspberry Pi GPIO, Import and use the RPi GPIO

1. Download the library:

$ wget http://pypi.python.org/packages/source/R/RPi.GPIO/RPi.GPIO-0.2.0.tar.gz#md5=0fc4bfa6aabc856b0b75252a40ac75cc

2. unzip the file:

$ sudo tar -zxvf RPi.GPIO-0.2.0.tar.gz

you can remove the .tar.gz at that point

3. get into the directory you just created:

$ cd  RPi.GPIO-0.2.0

4. The devs included a great install script with this package, run it to install with:

$ sudo python setup.py install

Now you should see a bunch of text in the command line. I have no idea why, but my first run of this command didn’t “take” but I ran it again and now it works great.

 

To use this, you need to know what pins correspond to pins on the RPi. You can google this yourself.

 

Now we get writing code. I’m using a graphical python editor called geaney which comes pre-loaded with squeeze.

 

To blink pins 11 and 13, use and run this python script.

You can see the plaintext version of that script here.

 

Essentially i’m trying to mimic things I’ve done with an Arduino for some time.

Maybe later today (if I can somehow find a 100ohm resistor) I’ll work on using inputs. I have a PIR motion sensor with me, but I neglected to bring the proper resistor to use it. I do have tack switches and resistors for those, which I could use to mimic the motion detector, but I don’t think that would be as cool.

 

Hey! This post was written a long time ago, but I'm leaving it up on the off-chance it may help someone. Proceed with caution. It may not be a good idea to blindly integrate this code or work into your project, but instead use it as a starting point.