Raspberry Pi for Voron — Complete Setup and Alternatives Guide

Electronics Klipper Guide

Why a Raspberry Pi?

The Raspberry Pi runs Klipper firmware, which offloads motion planning and print management from the MCU to the Pi. Klipper generates step pulses using the Pi's CPU, enabling higher step rates, more sophisticated kinematics, and real-time features like input shaping and pressure advance. The Pi also runs Moonraker (API server) and Fluidd or Mainsail (web interface). Without a Pi (or equivalent single-board computer), Klipper cannot run — the Pi is the brains of the printer.

Pi Models for Voron

Not all Raspberry Pi models are suitable for running Klipper with a Voron. Here is the breakdown from recommended to minimum viable.

Raspberry Pi 4 (2GB minimum, 4GB recommended)

The Pi 4 is the de facto standard for Voron builds. With a quad-core Cortex-A72 CPU running at 1.8GHz and up to 8GB RAM, it has ample headroom for Klipper + Moonraker + Fluidd/Mainsail simultaneously. The 2GB model works fine for basic use but the 4GB model is preferred because it gives more room for browser-based monitoring, webcam streaming, and future Klipper features. The Pi 4 supports USB 3.0 (blue ports), Gigabit Ethernet, and dual HDMI outputs — though only the USB 3.0 is practically useful for connecting an ADXL345 accelerometer for input shaper calibration.

Raspberry Pi 5 — Future-Proof

The Pi 5 (released late 2023) offers a substantial performance improvement over the Pi 4: a quad-core Cortex-A76 at 2.4GHz, faster GPU, and significantly improved I/O bandwidth. For Voron use, the Pi 5 provides better CANBus performance because the USB controller handles higher throughput without latency spikes. The Pi 5 also has a more efficient power management IC that reduces thermal throttling. However, the Pi 5 runs hotter than the Pi 4 and requires active cooling (the official active cooler is recommended). As of early 2025, Klipper support on Pi 5 is mature and stable. If building a new Voron, the Pi 5 is the best choice for longevity.

Raspberry Pi 3B+ — Minimum Viable

The Pi 3B+ can run Klipper, but it is at the edge of acceptable performance. The quad-core Cortex-A53 at 1.4GHz and 1GB RAM are sufficient for basic Klipper operation with a single MCU. However, adding webcam streaming, a CANBus interface, or complex macros will strain the Pi 3B+. The USB 2.0 ports are slower, and the single-core performance is significantly below the Pi 4. Use a Pi 3B+ only if you already have one and are building a minimal Voron V0.2 or Trident. Avoid it for a feature-rich V2.4 build.

Raspberry Pi Alternatives

Due to past Raspberry Pi shortages and ongoing price increases, several alternatives have become popular in the Voron community.

CB1 — BTT Pi's Processor

The CB1 (BigTreeTech's own module) is a drop-in replacement for the Raspberry Pi Compute Module 4 (CM4). It uses an Allwinner H616 quad-core ARM Cortex-A53 processor at 1.5GHz with 1GB or 2GB RAM. The CB1 is designed to plug into BTT's Manta M8P/CB1 or Manta M5P/CB1 mainboards, which have an integrated CM4 slot. Performance is roughly equivalent to a Pi 3B+ — adequate for Klipper but not as fast as a Pi 4. The CB1 is a cost-effective choice if you are already buying a BTT mainboard with the CM4 slot. Note: the CB1 runs hot and needs a heatsink plus airflow.

BTT Pi — Standalone CB1 Board

BigTreeTech also sells the BTT Pi, a standalone single-board computer with the CB1 module pre-installed. It includes HDMI, USB, Ethernet, and an SD card slot. The BTT Pi is essentially a Pi 3B+ equivalent with the same limitations. It is a good budget option if you cannot source a Pi 4 or Pi 5. Price is typically $30-40.

Orange Pi 3 LTS

The Orange Pi 3 LTS is a Raspberry Pi 3B+ competitor with an Allwinner H6 quad-core Cortex-A53 at 1.8GHz, 1GB or 2GB RAM, Gigabit Ethernet, USB 3.0, and HDMI. It is faster than the Pi 3B+ but not as fast as the Pi 4. Klipper runs well on it with Armbian or Debian. The main downside is community support — fewer people use Orange Pi for Klipper, so troubleshooting is harder. If you are comfortable with Linux, it is a viable budget option.

Leapfrog — CM4 Alternative

Leapfrog is another CM4-compatible module from the Chinese manufacturer Fuyuan. It uses a Rockchip RK3566 quad-core Cortex-A55 at 1.8GHz with up to 4GB RAM. Performance is between Pi 3B+ and Pi 4. Like the CB1, it runs hot and needs heatsinking. It is compatible with Manta boards that have a CM4 slot. Less common than CB1 but generally more capable.

Why Pi 5 Over Pi 4 for Voron

The Pi 5 brings tangible benefits to Voron builds, especially as printers become more complex:

• Better CANBus performance: The Pi 5's USB controller has lower latency and higher throughput. When using a USB-to-CAN adapter (e.g., U2C), the Pi 5 can handle higher CAN bus speeds (1Mbps) without frame drops or communication errors.
• Faster MCU communication: Klipper communicates with the MCU over serial or CAN. The Pi 5's faster CPU reduces the interval between step pulse generation, allowing smoother motion at higher accelerations.
• More headroom for webcams: If using a webcam for remote monitoring, the Pi 5 can handle 1080p or even 4K streaming via gstreamer without impacting Klipper's real-time performance.
• Future Klipper features: As Klipper adds more computationally intensive features (better trajectory planning, multi-MCU communication, advanced filtering), the Pi 5 will remain viable longer than the Pi 4.

SD Card Performance

The SD card is the most common point of failure in Pi-based Klipper setups. Klipper writes log files continuously, and poor-quality SD cards degrade quickly, causing slowdowns, corruption, or complete failure.

• Recommended: Samsung EVO Plus or EVO Pro (32GB or 64GB). These cards have high random I/O performance and good longevity. The EVO Plus is the community standard. The EVO Pro offers better write endurance for heavy logging.
• Avoid: No-name cards, Sandisk Ultra (high failure rate in Klipper due to write caching behavior), and cards sold as "industrial" but with unknown controllers.
• Size: 32GB is plenty for Klipper + Moonraker + configs + some g-code history. 16GB is the minimum. Larger cards (>64GB) are fine but wasteful for this application.

Performance Tuning

To maximize Klipper's real-time performance on a Pi, configure these system settings:

• Disable HDMI: If running headless (no monitor), add disable_splash=1 and hdmi_blanking=1 to /boot/config.txt. This frees GPU memory and reduces power consumption.
• Disable WiFi and Bluetooth: If using Ethernet, disable WiFi and Bluetooth in /boot/config.txt by adding dtoverlay=disable-wifi and dtoverlay=disable-bt. This reduces interrupt overhead.
• CPU governor performance mode: Set the CPU governor to performance to prevent the kernel from downclocking the CPU when idle: sudo cpufreq-set -r -g performance. Add this to /etc/rc.local for persistence.
• I/O scheduler: Set the I/O scheduler to none for the SD card to reduce latency: echo 'none' | sudo tee /sys/block/mmcblk0/queue/scheduler.

Klipper-Specific Pi Configuration

Klipper's real-time performance depends on stable CPU performance. Thermal throttling is the biggest risk — when the Pi's CPU reaches 80°C, it downclocks to reduce heat, causing Klipper to miss step pulses and produce print artifacts. Prevent thermal throttling with:

• Heatsink: Install a large heatsink (copper or aluminum fin stack) on the Pi's CPU and memory chips.
• Fan: Add a dedicated fan blowing across the heatsink. In a Voron enclosure, the ambient temperature can reach 50-60°C, making passive cooling insufficient. Use a 30mm or 40mm fan connected to the Pi's 5V GPIO pins or directly to the PSU via a buck converter.
• Thermal monitoring: Check CPU temperature with vcgencmd measure_temp. Keep it below 70°C for consistent performance.

Pi Failure Symptoms

Knowing the common failure modes helps you diagnose problems quickly:

• Corrupted SD card: The Pi fails to boot, or boots to a read-only filesystem, or loses configuration after reboot. Solution: re-flash the SD card from a known-good backup image.
• Power issues: Undervoltage warnings (the lightning bolt icon) in the Pi's output. Common causes: insufficient PSU (use a dedicated 5V/3A PSU or a quality buck converter from the 24V rail), poor USB cable (use a thick 18AWG cable), or voltage drop over a long cable. Undervoltage causes random Klipper disconnects and corrupted SD card writes.
• Overheating: The Pi spontaneously reboots or shows performance degradation. Check with vcgencmd measure_temp. Fix with better cooling.
• Dead Pi: Complete failure to power on. Usually the result of ESD damage, a short circuit on GPIO pins, or cumulative thermal damage. Replace the Pi.

Backup Pi SD Card Image Practice

Always keep a backup of your Pi's SD card image. When the SD card fails (and it will), you can restore in 10 minutes instead of spending hours re-configuring. Procedure:

1. Shut down Klipper and remove the SD card.
2. Insert the SD card into a computer and use dd (Linux/macOS) or Win32 Disk Imager (Windows) to create an image file.
3. Compress the image with gzip: gzip -9 klipper-backup.img
4. Store the compressed image on a NAS, cloud storage, or external drive.
5. Label the backup with the date and Klipper version.

Alternatively, use Kiauh's built-in backup feature (./kiauh.sh - backup) to preserve configuration files, then re-flash a fresh Pi OS.

Pi Hat/Addons

Several add-on boards are commonly used with a Pi in Voron builds:

• ADXL345 accelerometer: Used for input shaper calibration. Connects via USB (via a USB-ACC adapter) or directly to GPIO. USB is preferred because it isolates the accelerometer from the Pi's power noise and makes it easy to disconnect after calibration. The ADXL345 must be mounted directly on the print head (on the toolhead) and on the bed to gather resonance data.
• U2C (USB to CAN) adapter: BTT's U2C board converts USB to CAN bus for toolhead communication. Connects to the Pi's USB port and provides CAN_H/CAN_L terminals for the toolhead cable.
• UPS hat: Uninterruptible power supply for the Pi. Provides clean shutdown during power loss. Overkill for most Voron setups.

Powering the Pi from the PSU

You can power the Pi from the Voron's 24V PSU using a buck converter to step down to 5V, or use the official Raspberry Pi PSU. Important rules:

• Use a buck converter or official PSU. Never power the Pi from the 5V pin of the mainboard (e.g., Octopus or SKR). The mainboard's 5V regulator is not designed to supply the Pi's current draw (2-3A). Doing so will overheat the regulator and cause instability.
• Buck converter wiring: Input from 24V PSU (ensure rated for at least 3A output at 5V), output to Pi's GPIO 5V and GND pins (pin 2/4 for 5V, pin 6/9/14/25/30/34/39 for GND). Use a quality buck converter (LM2596 or similar) and set the output voltage to exactly 5.1V to compensate for wire voltage drop.
• Diode protection: Add a Schottky diode (1N5819) on the 5V input line to prevent back-powering the Pi through the USB port if you plug in a USB cable while the PSU is active.