The PiBot CNC Pendant V4.0 is a handheld ESP32-based controller that gives CNC router, laser engraver, and pen plotter operators a physical interface for machines running FluidNC or GRBL-HAL firmware. It connects via RJ12 wired cable or Bluetooth, ships pre-configured at 115200 baud for plug-and-play use, and supports wired speeds up to 1,000,000 baud for lower-latency control.
The hardware packs a capacitive touchscreen (approximately 8.9 cm (3.5 inches)), an industrial-grade encoder wheel, a potentiometer knob, a 4-position band switch, three independent front-panel switches, and a built-in speaker for status feedback, all in a 165 x 60 mm (6.5 x 2.4 inch) enclosure weighing 365 g (12.9 oz). The dual-PCB design leaves room for IO expansion, and the enclosure STL files are freely available for DIY repairs or customization. Power comes from an 18650 flat-top battery with onboard charging via USB-C, though PiBot warns that the battery must be removed when using the RJ12 wired connection to avoid a voltage imbalance that can damage the ESP32.
There is one notable firmware consideration for prospective buyers. Lumen Works Engineering documented that the pendant's default FluidNC settings allow the encoder to flood the motion buffer, which can stall movement or trigger unintended reverse motion. The fix is a custom fork of the FluidDial firmware, available on the Lumen Works Engineering GitHub repo, which resolves the buffer issue and enables the band switch and potentiometer jog speed control. PiBot and the ESP3D project's Luc are also co-developing a dedicated PiBot UI with microSD card upgrade support, coming in a future firmware release.
For Linux users, the pendant targets the FluidNC and GRBL-HAL ecosystems rather than LinuxCNC, and a January 2026 thread on the LinuxCNC forum reflects early community interest in bridging that gap, with members exploring whether the device could be mapped through LinuxCNC's hal_input layer if it presents a USB HID interface. Users running FluidNC-based machines on Linux are in better shape, as open-source G-code senders like Universal Gcode Sender run cross-platform and pair naturally with the firmware the pendant is built around.
The PiBot CNC Pendant V4.0 is available from the PiBot Store for $80 (EUR 74), discounted from $100 (EUR 92). Each package includes the main unit, two Bluetooth TX/RX modules, a Bluetooth adapter, an RJ12 module, and a 1-meter communication cable.
