GUSender

How it works

GUSender can live on your CNC controller. A tiny loader file (4 KB) is stored on the controller's storage. When you open the controller's IP in any browser, the app loads instantly from cache (or downloads once on first visit), your machine config loads from the controller, and it auto-connects.

For machines that are not networked, or when you want a native app shell, the desktop companion runs the same sender with a local HTTP/WebSocket facade. It can proxy a network controller or present a USB serial machine as a sender-compatible localhost machine.

Config, macros, probe settings, and MQTT options travel with the machine profile. Set up once, connect from a browser, the desktop companion, a tablet, or a phone pendant.

Install

Copy two files to your controller's storage. Takes about 2 minutes.

Open in a browser

Type your controller's IP. The app loads instantly from cache after the first visit.

Run jobs

3D toolpath, jog pad, probing, auto bed leveling, tool changes — everything's built in.

Add a phone pendant

Point a phone at the same machine URL. MQTT mirrors the sender and grants one active pendant at a time.

Use USB when needed

Launch the desktop companion for USB serial machines or as a localhost proxy for network controllers.

Features

Built for serious CNC work: live position tracking, full job execution, probing, leveling, tool changes, observers, phone pendant control, and a standalone companion app when the controller cannot host everything itself.

Machine Control

Live DRO with work and machine coordinates
Per-axis zero, Zero XY / Zero Z (hold-to-trigger)
Jog pad with diagonals, adjustable steps + feed
Feed / rapid / spindle override sliders
Spindle CW/CCW/Stop, coolant flood/mist
Laser/CNC mode switching
Programmable macro buttons

3D Toolpath Viewer

Real-time 3D visualization of loaded G-code
Rapids in red, cuts in cyan, completed in green
Live tool position marker during jobs
Rotary / 4th-axis with cylinder wrapping
Virtual playback scrubber
Tool isolation — highlight one segment

Job Execution

Stream G-code over WebSocket with flow control
Run jobs from SD card with live progress
Start-from-line resume after a stop
Job framing — trace bounding box first
Duration and time-remaining estimates
Large G-code text preview stays responsive with virtualized rows

Probing

Z, X, Y, XY, and XYZ probing
Shared active-probe model for 3D probes and touch plates
Center bore and boss probing
Split rectangular stock center: Center X and Center Y in separate clamp-safe passes
Workpiece rotation measurement, job-start application, and clear guardrails
Touch probe verification before each operation
Phone pendant probe controls follow the sender's active probe

MQTT Pendant + Observer

Phone pendant mirrors DRO, job state, tools, and probe setup
Hold-to-arm grant with one active pendant at a time
Desktop controls lock while the pendant owns control
Heartbeat, Last Will, page-hidden, and inactivity release paths
Observer tabs mirror jobs and machine state, then take primary when needed

Desktop Companion

Standalone Linux, Windows, and macOS app builds
Network profiles fetch controller config by IP
Local HTTP/WebSocket proxy keeps sender settings simple
USB serial sender mode for non-networked machines
Desktop zoom controls for high-DPI screens
Optional built-in MQTT broker support is planned for the companion path

Auto Bed Leveling

Probe a grid across your workpiece
Bilinear interpolation on every G-code line
Export / import height maps (.xyz)
Pre-leveled G-code for SD card jobs
Visual height map with color gradient

Tool Changes

Automatic ack via grblHAL protocol
"TOOL CHANGE" status throughout the M6 sequence
Toolchange timeline with cut time per tool
Custom Z-zero G-code support
Safety alert when grblHAL toolchange coordinates are not configured

SD Card

Browse, upload, download, delete files
Upload via HTTP or YMODEM
Visualize before running
Desktop USB path can stream jobs without requiring controller networking

Settings

Browse and edit all grblHAL settings
Search by name, description, or option
Track changes and write individually or in batch
Full backup and restore (JSON)

Job Reconnect

Close your browser mid-job? Open it again.
Shows job name, percentage, time remaining
Amber bounds rectangle on the toolpath
Tool change timeline restored
Auto init when the job finishes