ADXL345 USB Accelerometer Board for Klipper Input Shaping Portable Resonance Sensor

Specifications

• Sensor Type: MEMS 3-Axis Accelerometer (ADXL345)
• Onboard Processor: Raspberry Pi RP2040 (Dual-core ARM Cortex-M0+)
• Interface: USB Type-C (Data & Power)
• Mounting: Standard 3D Printer hole spacing (Supports Voron StealthBurner & Afterburner mounts)
• Voltage: 5V (USB Powered)
• Firmware Support: Klipper (Pre-flashed or easily updating via USB)
• Dimensions: Compact form factor for lightweight toolhead mounting

Applications

• Voron & RatRig Tuning: Essential for dialing in high-speed CoreXY machines.
• Ender 3/Creality Speed Upgrades: Push your bed-slinger to 3000mm/s² acceleration without ringing.
• Portable Diagnostics: Use one unit to calibrate multiple printers in a farm setup.
• CNC & Laser Diode Machines: If you run Klipper or a compatible firmware on a lightweight CNC/Laser engraver, this sensor can prevent the laser head from jittering during fast engraving passes.

Project Evolution

 From "Guesswork" to "Scientific Tuning" If you are manually adjusting your "Jerk" and "Acceleration" settings based on visual inspection, you are printing blind.

• The Upgrade: This board unlocks Klipper’s Input Shaping algorithm. By measuring the actual vibrations of your machine , Klipper can mathematically cancel out resonance frequencies.
• The Result: You can often double your printing speed while improving surface quality.
• Effort Level: Intermediate. Requires a working Klipper installation (Mainsail/Fluidd).

Virtual Technician Steps (Summary)

• Step 1: Physical Mounting
• Step 2: Firmware Compilation (RP2040)
• Step 3: Flashing the Firmware
• Step 4: Finding the Serial ID
• Step 5: printer.cfg Configuration
• Step 6: Testing & Calibration

Package Includes: 1 x FLY-ADXL345 USB Accelerometer Board

Frequently Asked Questions (FAQ)

• Does this work with Marlin firmware?
  No, this is specifically designed for Klipper firmware which handles the high-speed data processing.
• Do I need to leave this connected permanently?
  No. You connect it, run the calibration, save the config, and then remove it to save weight on the print head.
• Does it come with a USB cable?
  No, this listing is for the board only. You will need a high-quality USB-C data cable.
• Why use this over a generic ADXL345 module?
  Generic modules require SPI wiring (4-6 delicate wires) to the Pi's GPIO headers. This unit uses a single robust USB cable.
• Can I use this on a Bed Slinger (Ender 3)?
  Yes. You will need to mount it to the nozzle (X-axis) and then move it to the bed (Y-axis) to measure both, or buy two units.
• Is the RP2040 pre-flashed?
  Typically yes, but Klipper updates often require re-flashing. The board acts as a standard UF2 drive for easy drag-and-drop flashing.
• How do I flash the firmware?
  Hold the "Boot" button while plugging it into a PC. It mounts as a drive. Copy the klipper.uf2 file compiled for RP2040.
• What if my ls /dev/serial/by-id/* shows nothing?
  Try a different USB cable. Many USB-C cables are "charging only" and lack data lines.
• Can I mount this with double-sided tape?
  Not recommended. Tape acts as a damper and absorbs the vibrations you are trying to measure. Use screws.
• Does it support 5V or 3.3V logic?
  The board handles all logic level conversion internally. You just supply 5V via USB.
• Will this fix "VFA" (Vertical Fine Artifacts)?
  It helps, but VFA is often mechanical (belts/motors). This fixes "Ghosting" (ripples after corners).
• Can I use this with a Raspberry Pi Zero 2W?
  Yes, as long as you have a way to connect the USB cable (using a USB OTG adapter).
• What is the accel_per_hz setting?
  This determines the intensity of the vibration test. Default is usually fine, but heavy beds might need adjustment.
• Does it interfere with my BLTouch/Probe?
  No, it is a completely separate system used only during calibration.
• How often should I recalibrate?
  Whenever you tighten belts, change the nozzle assembly weight, or move the printer to a less stable table.
• Is the connector USB-C or Micro-USB?
  This model uses a modern USB Type-C connector.