State persistence

Power goes out? Hit the e-stop? No problem. The FluidBoard remembers exactly where it was.

A dedicated persistence chip saves your machine state in real time — not to flash memory that wears out, but to a chip specifically designed for unlimited writes. Your state is saved roughly 10 times per second, so even a sudden power loss won't set you back.

Why this matters

On most controllers, hitting the e-stop means re-homing, re-zeroing your work offset, and hoping you can pick up where you left off. With the FluidBoard, you simply power back on and continue. No re-homing, no re-measuring, no scrapped parts.

This is especially valuable on lathes, where losing your tool offsets mid-job can mean scrapping the workpiece. And it means you're never punished for using the e-stop — which is exactly how it should be. Safety features should feel safe to use.

What is saved

• Machine position on all axes — no re-homing needed
• Homing status — the board knows which axes were already homed
• Work offsets and coordinate systems
• Feed rate, spindle speed, and all active G-code states
• Feed, rapid, and spindle overrides
• Current tool and turret position
• G-code variables (# parameters)

Configuration

State persistence is enabled by default. If you change your machine configuration (for example, adding an axis or changing motor assignments), the board detects this automatically and asks you to re-home once. After that, persistence resumes.

state_persistence:
  cs_pin: gpio.5
  save_interval_ms: 100
  spi_freq_mhz: 20
  save_parameters: true

After a power loss, persistence keeps your position accurate as long as the motors held their position while power was off. If your motors don't have holding torque (idle_ms is not 255) or were bumped by hand, you should re-home.