Introduction: 1NMCT Project I PetPort

This is a build guide for the cat lock that I created. I recommend reading through the whole guide before starting to recreate this project. I ran into some problems while building this so by reading this guide first, you may be able to evade these problems.

Step 1: Scheme

This is the fritzing scheme for this project.

Step 2: Making the Port

· Make a square hole that has approximately the same size as the square wooden panel in the wooden panel, this will be the hole for the cat to walk through.

· Put screws in the left and the right side of the square panel.

· Drill a hole in the left and the right side of the wooden panel. These holes will be used to put in the screws from the square panel.

· Put the square panel in the hole of the wooden panel by fitting the screws into the holes.

Step 3: Adding Electronics

· Drill 1 small hole underneath the port on each side of the wooden panel. Here we will attach the object detect sensors.

· Align the holes in the modules with the drilled holes.

· Screw the object detect sensors to the panel.

· Glue 1 servo motor on each side of the wooden panel as shown on the picture.

Step 4: Making the Base of the Frames

· Take 1 large plank and create a hole like shown on the picture. This has the same dimensions as the LCD display. Drill a hole on each corner. Make sure it is lined up with the holes in the LCD display.

· Take 2 of the large wooden planks and 2 of the small ones. Align them in the same way as in the picture and drill 4 holes. Do this for all planks.

· Then use a metal plate to attach the planks to each other.

· Now do the same for the other planks.

· Take the frame with the LCD hole and screw the LCD display onto the frame.

· Take the other frame and drill a hole in one of the sides. This will be used to put the wires of the RFID reader through. Also drill 4 small holes in this frame to attach the RFID reader.

Step 5: Finishing the Framework

· Take the thin planks and glue them onto the frame with the RFID. It should look like this. Notice that there is a small cut in the frame. This is used to put the cables of the object detect sensor through.

· For the LCD frame it is a bit trickier. You will have to put smaller pieces of wood on both sides. Also, make sure there is an opening on the left side of the frame (as shown on the picture). This will be used to put the wires through.

· Now make the inside frame for both frame. The result should look like this.

· Take the frame with the RFID reader. Screw the DS3231 on the inside of the frame.

· Extend the wires of the LCD and the DS3231 and put them through the opening on the side.

· Align the frame onto the wooden panel with the port and look at where the sensor and the servo motor is. Carve a space that is large enough to fit them into the frame.

Step 6: Finishing the Build

· Make a hole in the wooden panel like this. We will put the wires from the other side through here. This way, all wires will reach the raspberry pi.

· Make sure the wires are long enough to reach the raspberry pi.

· Attach the wooden panel to the stand (wooden panel of 70 x 30 x 2) You can do this with glue or with screws. For sturdiness, you can add these metal angle brackets.

· Attach both of the frames to the wooden panel.

Step 7: Connect the Wires to the Raspberry Pi

· The last thing we will need for this step to do is to connect all wires to the raspberry pi.

  • LCD :
    • VSS
    • VDD --> 5V
    • V0 --> middle trimmer pin (other trimmer pin to 5V and GND)
    • RS --> GPIO 20
    • RW --> GND
    • E --> 21
    • D4 --> 13
    • D5 --> 19
    • D6 --> 26
    • D7 --> 12
    • A --> 5V
    • K --> GND
  • Object detect sensor 1:
    • VCC --> 3.3V
    • GND --> GND
    • OUT --> 5
  • Object detect sensor 2:
    • VCC --> 3.3V
    • GND --> GND
    • OUT --> 6
  • DS3231:
    • SQW --> GPIO 17
    • SCL --> SCL
    • SDA --> SDA
    • VCC --> 3.3V
    • GND --> GND
  • RFID reader
    • SDA --> CE0
    • SCK --> SCLK
    • MOSI --> MOSI
    • MISO --> MISO
    • GND --> GND
    • RST -->GPIO 25
    • 3.3V --> 3.3V
  • Servo motor 1
    • Orange wire --> 23
    • Brown wire -->GND
    • Red wire --> 3.3V
  • Servo motor 2
    • Orange wire --> 24
    • Brown wire --> GND
    • Red wire --> 3.3V

Step 8: Setting Up the Raspberry Pi

Clone these files onto your raspberry pi.

https://github.com/NMCT-S2-Project-I/project-i-Arn...

Then clone this repository on the pi. You will have to adjust some files to match your project.

https://github.com/NMCT-S2-Project-I/Project-I

Then copy the 2 services to /etc/systemd/system and enable both of them.