Hiddenpool Scale Model

Hello for a school project we had to make something with raspberry pi and electronics.

I have chosen to make a swimming pool that you can open or close with a button on a site. And you can also see the temperature from outside, I have used an inductive proximity sensor for seeing if the swimming pool is open or closed. And I used a PIR to observe movement, so the swimming pool can’t open or close with someone on.

Step 1: The Components

The list of components can be found in the pdf below.

· Raspberry pi 3 model b

· Temperature sensor DS18b20

· Inductive capacitive sensor lj12a3-4-z/bx

· Mcp3008

· PIR

· stepper motor 5 volt and uln2003 driver

· i2c lcd

· cables to connect the sensors to the raspberry pi. ( female – male)

· 2x rod 8 mm

· 2x pulley 5mm

· 4x sliding guides 8mm

· Drive belt

Step 2: Electric Scheme

See scheme for connecting the components.

Step 3: Setup Pi

For the image you can always download it from the raspberry pi website.

The only thing we need to do next is to make the ipaddress static.

We can do this by using the command sudo nano /etc/dhcpcd.conf and use the settings from bellow.

After you have made the ip address static you can now connect with the pi by connecting a network cable from the pi to your computer.

Then I’ve used the program mobaxterm and made a connection to my pi.

When you’re connected to the pi you can make a internet connection by using sudo raspi-config.

- Network options – wifi

- SSid : the name of your network

- Psk : password of the network

When you reboot the pi you have internet access.

Step 4: Database

First we started with making a database. My database is made with mysql workbench this is easy to import on the pi.

The standard login on the pi is : username: pi, password:raspberry.

I made 2 tables the first is for the sensors and the other is for the history. So in my table sensors I have 3 records. One for my temperature sensor, one for my PIR and one for my inductive proximity sensor. In the other table I have put the values from the sensors, especially the temperature sensor.

Step 5: Construction

First I made some 3dprinted holders for the sliders and the pulley. You can find the files at the github directory.

Then I used a piece of wood that I still had you can find the sketch in the images. I attached the printed pieces to the 2 ends of the board. This is attached with screws. Then I put the rods in the 3d printed pieces.

At the other side of the 3dprinted piece I put the pulley. The other pulley is for the step motor.

Then I have made a wooden board that will represent the surface.

I attached this board on the sliding guides with a few screws.

Then I attached the drive belt with a few screws to the bottom of that board. This drive belt goes from one pulley to the pulley on the stepper motor.

Next I made a box that fits over the wooden board. So the only thing we can see is the pool.

I have taken two planks of 75cm by 40cm. One plank is for the bottom and the other for the top. Then I cut a hole in one of them like the sketch above.

Then I have sawn planks like the sketch below this is for the border.

I attached this borders on the plate with screws.

I also made a few holes for the lcd and for the pir.

I laid a grass mat and tiles on the plank for decoration. Also I have painted the bottom blue.