Swapping Raspberry Pi 4 for Raspberry Pi 5 in sBITX Transceiver

This guide outlines the key considerations and modifications required to upgrade from a Raspberry Pi 4 to a Raspberry Pi 5 in the sBITX transceiver. The Pi 5 offers improved performance but requires specific hardware and case adjustments due to differences in power, display connectors, thermal management, and physical layout.

1. Power Supply Upgrade

The Raspberry Pi 5 has higher power demands than the Pi 4. To ensure stable operation:

• Regulator Requirement: Use a 5V regulator rated for at least 5A. Set the output voltage to 5.3V to compensate for voltage drops.
• Why It Matters: Insufficient power can prevent the Pi 5 from booting or cause instability. Check for under-voltage warnings by running the following command in the terminal:

  vcgencmd pmic_read_adc
  

  If under-voltage is detected (e.g., VDD_CORE below 4.8V), confirm your regulator meets the 5A requirement.
• Recommendation: Purchase a reliable 5V/5A regulator board, such as the DROK DC 5V Power Converter or equivalent, available from retailers like Amazon.

2. Display Connector Compatibility

The Pi 5 uses a different display connector than the Pi 4, requiring a new cable for the official 7-inch Raspberry Pi touchscreen display.

• Connector Difference: The Pi 5 has a 22-pin FPC (Flexible Printed Circuit) connector, while the Pi 4 uses a 15-pin connector.
• Required Cable: Purchase the official Raspberry Pi Display Cable (Standard to Mini, 500mm) to connect the Pi 5 to the 7-inch display.
• Note: Verify the cable length suits your sBITX enclosure. Ensure proper alignment when connecting to avoid damaging the pins.

3. Enhanced Cooling Requirements

The Pi 5 generates significantly more heat than the Pi 4 due to its higher performance.

• Cooling Solution: Install an active cooling system, such as a fan or heatsink with a fan (e.g., Raspberry Pi Active Cooler). Passive cooling may not suffice under load.
• Thermal Monitoring: Monitor CPU temperature using the following command in the terminal:

  vcgencmd measure_temp
  

  Aim to keep temperatures below 70°C for optimal performance and longevity.
• Implementation Tip: Ensure the cooling solution fits within the sBITX enclosure and does not obstruct other components. Secure airflow paths to prevent heat buildup.

4. Case Differences for V2 and V3 Enclosures

The physical layout of the Pi 5 differs from the Pi 4, requiring modifications to or replacement of the sBITX V2 or V3 case side panel.

• Layout Differences: The Pi 5 has relocated ports (ethernet and USB) and a different mounting hole pattern.
• Modification Steps:
  1. Measure and Mark: Compare the Pi 5’s port layout to the existing side panel. Use a template or the Pi 5 board to mark new cutouts for USB and ethernet ports.
  2. Cut and Drill: Use a Dremel or precision cutting tool to modify the side panel. Ensure clean edges to maintain the enclosure’s appearance.
  3. Mounting: Verify that the Pi 5’s mounting holes align with the case or add new standoffs if needed.
• Replacement: The development team has provided files for 3D-printable replacement end plates for the sBITX case side panels at this topic on our Discord server, more info here.

Additional Notes

• Software Compatibility: Ensure the sBITX software is compatible with the Pi 5. Update to the latest sBitx 64-bit Pi image and check for sBITX software updates on HERE.
• Testing: After assembly, test all components (display, audio, and RF functionality) to confirm proper operation. Use the following command to check for hardware errors in the system log:

  dmesg
  

• Community Resources: Consult the sBITX wiki here or the Discord group for troubleshooting and additional tips.

By addressing these considerations, you can successfully upgrade your sBITX transceiver to a Raspberry Pi 5, leveraging its enhanced performance while maintaining reliability.