Lucky Cam.

What Lucky Cam will eventually do

Lucky walks past → a PIR notices motion → Python tells the camera to take a photo → the new photo replaces the old one → a web page displays the newest image.

Lucky only

A camera in a studio needs a purpose and a boundary.

• Point the camera low at a route Lucky actually uses.
• Frame the shot so it does not capture faces, desks, doors or private work if you can avoid it.
• Test the frame before any automatic capture begins.
• Do not publish a photo containing a person just because the code worked.

Make a Cat Cam folder

1. Start the Pi and wait for the desktop.
2. Open File Manager.
3. Open Home → pi-projects.
4. Right-click an empty area → New Folder.
5. Name it cat-cam.
6. Press Enter, then double-click the new folder.

Identify your PIR before wiring it

A common PIR module has a white faceted dome. We need to identify its three electrical connections.

1. Pick up the PIR by its edges. Do not pull on the dome.
2. Find the three connection labels printed on the board: VCC, OUT, GND.
3. Point to each label before you connect a wire.
4. If the labels are hidden by a plug or case, ask your tutor to help identify them.

Wire the common HC-SR501

1. Shut the Pi down and disconnect power.
2. Connect PIR VCC to Pi physical pin 2 (5 V).
3. Connect PIR OUT to Pi physical pin 7 (GPIO4).
4. Connect PIR GND to Pi physical pin 6 (GND).
5. Trace all three wires from sensor label to Pi pin.
6. Have the wiring checked, then reconnect power and boot.

Create pir-test.py

1. Open Thonny → File → New.
2. Type:

from gpiozero import MotionSensor

pir = MotionSensor(4)

print("Waiting for movement...")
pir.wait_for_motion()
print("Something moved")

1. Choose File → Save As….
2. Go to Home → pi-projects → cat-cam.
3. Save as pir-test.py.
4. Click Run.

Give the sensor time, then move

Many PIR sensors need a short settling period after power-up.

1. After the Pi boots, leave the sensor still for about 30–60 seconds.
2. Run pir-test.py again if needed.
3. Move a warm hand or your body across the sensor's view, not directly toward it from far away.
4. Watch the Thonny Shell.

Choose the right camera cable

Attach the ribbon cable carefully

1. With power disconnected, find the Pi's camera connector for your model.
2. Gently pull the small connector flap outward until it stops, then tilt it slightly open. Do not remove the flap.
3. Hold the ribbon cable straight. On the Pi end, insert it with the metallic contacts facing away from the connector flap.
4. Push the cable in evenly so it is not crooked.
5. Tilt the flap back and press it closed to clamp the cable.
6. At the camera board, hold the camera with the lens facing down/away. Open its flap.
7. Insert the cable with the metallic contacts facing toward the camera board and away from that flap.
8. Close the camera connector flap.
9. Check both ends are straight and firmly seated.
10. Reconnect power and boot.

Open Terminal and preview the camera

1. Open Terminal from the taskbar, or Raspberry Pi menu → Accessories → Terminal.
2. Type rpicam-hello.
3. Press Enter.

Want more time to frame it?

1. Type rpicam-hello --timeout 0 and press Enter.
2. The preview now keeps running.
3. To stop it, hold the Ctrl key and tap C. This keyboard combination is written Ctrl+C.

If there is no preview

1. Read any message Terminal shows. Do not close it immediately.
2. Type rpicam-hello --list and press Enter.
3. If a camera is listed, the Pi can detect it. Try rpicam-hello again.
4. If no camera is listed, shut down and disconnect power.
5. Check both ends of the ribbon cable are fully inserted, straight, and the contacts face the correct direction.
6. Check you used a camera connector, not a display connector on an older board.
7. Reconnect power and test again.

Take one photo from Terminal

1. Open Terminal.
2. Type cd ~/pi-projects/cat-cam and press Enter.
3. Type pwd. Check the answer ends in /pi-projects/cat-cam.
4. Type rpicam-jpeg -o test.jpg and press Enter.
5. Wait for the preview/capture to finish.
6. Open File Manager → Home → pi-projects → cat-cam.
7. Double-click test.jpg.

Create camera-test.py

1. Open Thonny → File → New.
2. Before running anything, save the empty file in Home → pi-projects → cat-cam as camera-test.py.
3. Type:

from picamera2 import Picamera2
from time import sleep

camera = Picamera2()
camera.start()
sleep(2)
camera.capture_file("latest.jpg")
camera.stop()

print("Photo saved")

1. Choose File → Save.
2. Click Run.
3. Look in the Shell for Photo saved.
4. Open the Cat Cam folder in File Manager and double-click latest.jpg.

If camera-test.py fails

Now make the real Cat Cam program

At this point you have already tested both difficult parts separately:

Now we connect those two proven ideas.

1. Open Thonny → File → New.
2. Save the new file first as Home → pi-projects → cat-cam → cat-cam.py.
3. Then type the program on the next card.

Type, save, then run cat-cam.py

from gpiozero import MotionSensor
from picamera2 import Picamera2
from time import sleep

pir = MotionSensor(4)
camera = Picamera2()

camera.start()
sleep(2)

print("Lucky Cam is watching...")

while True:
    pir.wait_for_motion()
    camera.capture_file("latest.jpg")
    print("New photo saved")
    pir.wait_for_no_motion()

1. Choose File → Save.
2. Place the camera and PIR so your test movement is inside both fields of view.
3. Click Run.
4. Wait for the Shell to say Lucky Cam is watching....
5. Move across the PIR's view once.
6. Move away and stay still so the PIR can return to “no motion”.

Trigger it twice

1. With Cat Cam running, trigger the PIR once.
2. Open latest.jpg and look at the picture.
3. Change the scene: move an object, or move yourself out of frame and back into the sensor area.
4. Trigger the PIR again.
5. Reopen or refresh latest.jpg.

Make index.html

Before putting anything on the public internet, make a tiny web page on the Pi itself.

1. Stop cat-cam.py for a moment using Thonny's red Stop button.
2. In Thonny choose File → New.
3. Choose File → Save As… and save the new file in the Cat Cam folder as index.html.
4. Type the HTML below. This file is not Python; the browser will read it.

<!doctype html>
<html>
<head>
  <meta charset="utf-8">
  <title>Lucky Cam</title>
</head>
<body>
  <h1>Lucky Cam</h1>
  <img id="lucky" src="latest.jpg"
       alt="Latest Lucky Cam photo" width="640">

  <script>
    const luckyImage = document.getElementById("lucky");
    setInterval(() => {
      luckyImage.src = "latest.jpg?t=" + Date.now();
    }, 5000);
  </script>
</body>
</html>

1. Choose File → Save.
2. Do not click Run in Thonny. HTML is opened by a browser, not run as a Python script.

Let the browser see the Cat Cam folder

1. Open Terminal.
2. Type cd ~/pi-projects/cat-cam and press Enter.
3. Type ls. Check you can see index.html and latest.jpg.
4. Type python3 -m http.server 8000 and press Enter. You do not need to memorise this: python3 starts Python, -m http.server asks Python to use its built-in simple web-server module, and 8000 is the local network “door number” (port) we are using.
5. Leave that Terminal window open. It is now acting as a tiny local web server.
6. Open the Pi's web browser.
7. In the address bar type http://localhost:8000 and press Enter.

View it from another device

This is still local network only. It is not on the public internet.

1. Keep the web-server Terminal running.
2. Open a second Terminal window.
3. Type hostname -I and press Enter. This asks the Pi to show its current network addresses.
4. Look for an address made of four number groups, often beginning 192.168. or 10.. Example: 192.168.1.42.
5. Make sure the second device is on the same Wi-Fi/network as the Pi.
6. On the second device, type http:// + the Pi address + :8000. Example: http://192.168.1.42:8000.

What is left for the real online Lucky Cam?

The important hardware and learning are complete. Public publishing is a separate system choice, and it should not be improvised inside a beginner hardware lesson.