Subtitle: When your cat’s food depends on debugging a microcomputer...

🐱 Recap from Day-27

In Day-27, we:

• Flashed Raspberry Pi OS (Lite) onto a microSD card
• Enabled SSH by adding a file to /boot
• (Optionally) added Wi-Fi credentials via wpa_supplicant.conf
• Inserted the SD card into the Raspberry Pi and powered it on
• Ran nmap to identify the Pi’s IP — but couldn’t connect via SSH

📚 Table of Contents:

1. ✅ Confirming SSH Still Enabled
2. 🧠 Checking Possible Issues
3. 💻 Re-Insert & Recheck SD Card
4. 🌐 Trying .local Hostname
5. 🔌 Swapping Power & Boot Medium
6. 🧰 Hardware Test: Running the Servo Script
7. 🕒 Schedule with Cron
8. ✅ Final Status (Day-28)

🧪 Step-by-Step Troubleshooting

🔎 1. Confirming SSH Still Enabled

After scanning the network and identifying live hosts:

We attempted SSH But got:

🧠 2. Checking Possible Issues

💻 3. Re-Insert & Recheck SD Card

• Removed SD card
• Mounted it back on macOS
• Verified ssh file:

Output showed:

✅ SSH file still present

🌐 4. Trying .local Hostname:

But Fails ❌ :

🔎 Diagnosis: .local resolution (mDNS) not supported or not working on macOS without Bonjour or Avahi.

🔌 5. Swapping Power & Boot Medium:

Still not able to reach the Pi?

✅ Try this:

• Use another USB-C cable or power adapter
• Re-flash Raspberry Pi OS

This time, use Raspberry Pi Imager and make sure to:

• Enable SSH in the advanced options
• Set Wi-Fi SSID and password (if headless)

🧰 6. Hardware Test: Running the Servo Script:

After finally getting access:

You can now test your Python script that triggers the servo.

✏️ Example: feed_cat.py

🕒 7. Schedule with Cron:

Do Crontab -e and Add:

📅 This runs the script every day at 8:00 AM.

✅ 8. Final Status (Day-28)

📌 Lessons Learned:

• Enabling SSH by file still works — just double-check the boot!
• mDNS can be flaky; nmap is your friend.
• Power supply really matters for Pi stability.
• Servo motors may need external power for consistent operation.

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