Raspoulette Prototype

Hi guys,
When i see a raspberry pi contest i decide to make a prototype of an idea i had for few time, let me present my Raspoulette!
I will try to explain how to make an amazing Raspoulette!
Raspoulette is an autonomous solar powered closing systeme coop’s door based on raspberry pi. It’s mean that Raspoulette open the coop’s door when the sunlight is coming and close the door when is gone. To save energy i will explain how to make a twilight switch.

But first of all, what you need for this project :

solar interruptor :
-1 relay 12v dc
-1 LDR
-1 potentiometer 1M
-4 resistance r1=180k r2=10k r3=100 r4=4.7k
-3 transistor npn (bc547 like)
-1 diode

Voltage regulator :
-LM7805
-1 big capacitor
-male micro usb pin

Motor controller :
-1 L293
-12V Dc motor

Hardware part :
-1 big 10liters bottle
-1 old printer to take the rail systeme with the motor
-1 old drill’s batery
-1 piece of PVC tube
-Your Raspberry pi (I use model B but you probably can use a model A)
-tape
-some piece of wood

Software part :
-python

Step 1: Solar interruptor

For the interruptor we have to make an electric part to turn up and  turn off the raspberry, and also shell part to begin the python software.

This is the eletronic part explanation :
The first transistor will be blocked or not dependind the “divising bridge” composed by LDR and r1 (180k)+potentiometer. If there is enought light the 3 transistors conduct and energy can pass trought relay’s coil and active it.

If you are playing with the potentiometer you are able to configure how light you want to activate the relay.

And to begin the software it’s really easy, just type this on the shell :
sudo nano /etc/rc.local
then you can type on the last line :
sudo python /your_file_directory/Poulerail.py

The next time you will turn on your Raspberry, the software will begin automaticly

Step 2: Voltage regulator

LM7805.pdf350 KB

Step 3: Motor controller

We use DCmotor  because it’s the simplest solution, you just have to use the l293, it’s DC motor controller, not the cheapest one but easy to find and efficient.

I join the datasheet if you want more information.In this case we just use pin :
8 : +12V (motor)
2 : Rpi out
7 : Rpi out
1 : enable
16 : +5V (l293)
4, 5, 12, 13 : Ground
3 : Motor in
6 : Motor in

L293d.pdf204 KB

For more detail: Raspoulette Prototype