Build your Pi.

The SD card is the Pi’s “hard drive”. Right now it’s empty. We need to write the operating system — Raspberry Pi OS 64-bit — onto it.

1. Plug the microSD card into the laptop using the supplied adaptor.
2. Open Raspberry Pi Imager. (Already installed on the classroom laptops. If not, download it from raspberrypi.com/software.)
3. Click Choose device → Raspberry Pi 4.
4. Click Choose OS → Raspberry Pi OS (64-bit). Make sure it says “with desktop”, not “Lite”.
5. Click Choose storage and pick the SD card. Be careful here — if you choose the wrong drive you can wipe the laptop.
6. Click Next, then Edit settings. Fill in:
   • Hostname: pi-iot-XX (where XX is your kit number).
   • Username: coderra.
   • Password: a strong one. Write it down somewhere safe.
   • Wireless LAN: the school Wi-Fi name and password. Country: GB.
   • Locale: timezone Europe/Jersey, keyboard layout gb.
   • On the Services tab: tick Enable SSH with password authentication.
7. Save the settings, click Yes, and let the Imager write the card. This takes 4–6 minutes.
8. When it says “Write successful”, eject the SD card.

Time to power the Pi on for the first time and bring it up to date.

1. Insert the SD card into the slot on the back of the Pi.
2. Connect the microHDMI cable to HDMI 0 (the one closest to the USB-C port) and the other end to a monitor.
3. Plug in the keyboard and mouse.
4. Plug in the official USB-C power supply last. The Pi has no power button — it boots as soon as it gets power.
5. Wait for the desktop to appear. The first boot is slower than later ones.

Once you see the desktop, open a Terminal (the icon that looks like >_) and run:

sudo apt update
sudo apt full-upgrade -y
sudo reboot

This downloads the latest security updates and restarts the Pi. It can take 5–10 minutes the first time. You can read on while it works.

The official 5″ touchscreen connects to the Pi with one ribbon cable (called DSI) and four small jumper wires for power.

1. Unplug the Pi’s power supply.
2. Find the DSI port on the Pi (a thin slot labelled “DISPLAY” or “DSI”).
3. Open the connector by pulling the black tab gently outward.
4. Slide the ribbon cable in silver-side facing the USB ports. It only fits one way.
5. Push the black tab back in to lock it.
6. Do the same on the touchscreen’s connector.
7. Connect the four jumper wires for power: 5V → 5V, GND → GND, SDA → SDA, SCL → SCL. The labels are printed on both boards.
8. Plug in the power supply.

The touchscreen should light up and show the desktop after about 30 seconds. Try tapping the screen — you should see the cursor move and clicks register.

If the screen is upside down (depending on how it’s mounted), open a terminal and edit the boot config:

sudo nano /boot/firmware/config.txt

Find the line [all] and add this just below it:

display_lcd_rotate=2

Save with Ctrl+O, Enter, then exit with Ctrl+X. Reboot.

SSH is how you log into the Pi from another computer over the network. Right now it accepts a password. We’re going to upgrade it to use a key instead — a pair of files that work like a much, much longer password no one can guess.

Open a terminal on your laptop (not the Pi) and run:

ssh-keygen -t ed25519 -C "pi-iot-XX" -f ~/.ssh/pi_iot_XX

Press Enter when it asks for a passphrase (leave it empty for the classroom). This makes two files in your ~/.ssh folder: a private key (keep secret) and a public key (safe to share).

Copy the public key to the Pi:

ssh-copy-id -i ~/.ssh/pi_iot_XX.pub coderra@pi-iot-XX.local

It will ask for the Pi’s password one last time. Now log in with the key:

ssh -i ~/.ssh/pi_iot_XX coderra@pi-iot-XX.local

You should be in without typing a password. From the Pi shell, turn password login off:

echo "PasswordAuthentication no" | sudo tee /etc/ssh/sshd_config.d/99-iot.conf
echo "PermitRootLogin no" | sudo tee -a /etc/ssh/sshd_config.d/99-iot.conf
sudo systemctl restart ssh

From now on, only your laptop’s key can log in. Test it: open a new laptop terminal and try to SSH again. It should work without a password. Try removing the -i flag — if SSH falls back to asking for a password, lock-down didn’t take.

The Pi is portable, but only if the battery can keep up. A weak power bank causes the screen to flicker, the SD card to corrupt, or the Pi to reboot under load. We’re going to check yours before trusting it in a lesson.

Charge the power bank fully. Then:

1. Unplug the official PSU.
2. Plug the power bank into the Pi’s USB-C port.
3. Wait for the touchscreen to come up. Use it for 5 minutes — tap around, open the browser, watch a video on the BBC website.

Then SSH into the Pi and run:

vcgencmd get_throttled

You want to see this:

throttled=0x0

0x0 means everything is fine. Anything else (e.g. 0x50000, 0x50005) means the Pi noticed an under-voltage event. The bank or the cable can’t keep up.

Walk through this list before you call Phase 1 done. If anything is missing, fix it now — later phases assume all of this works.