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Rendalsniken edited this page Apr 26, 2026 · 4 revisions

DIY Welding Positioner Controller

ESP32-P4 / C6 GUITION JC4880P443C | Open-source firmware for TIG/MIG welding rotators

Current Status: v2.0.6 — diagnostics and preset polish

Release v2.0.6 adds the Diagnostics event log, per-preset workpiece diameter for STEP programs, Pedal Settings, Diagnostics, ProgramExecutor polish, start-request race fixes and documentation sync. Release v2.0.5 previously centralised cross-core atomics, added fatal_halt(), release-visible LOG_E, non-blocking ADS1115 reads and boot-time ESTOP de-floating. See CHANGELOG.md for the full list.

All core features tested and confirmed working on real hardware:

  • Motor rotation with live RPM adjustment (potentiometer + foot pedal; main screen has no RPM +/-)
  • All 5 welding modes (Continuous, Jog, Pulse, Step, Timer)
  • Hardware E-STOP with <0.5ms response + UI reset
  • 16 program preset save/load (NVS JSON blobs; legacy LittleFS migration on first boot if needed)
  • 21 active LVGL root screens (ScreenId) plus E-STOP overlay; settings, diagnostics, pedal settings, system info, calibration
  • Direction switch (GPIO29), foot pedal support
  • 8 accent color themes, brightness control, dim timeout

Quick Links

Page Description
Getting Started Build, flash, and first run
Architecture FreeRTOS dual-core design, state machine, thread safety
Hardware Setup Wiring diagram, driver config, BOM
Troubleshooting Common issues and solutions
Roadmap Completed features and future plans

Project Overview

Open-source welding positioner controller for rotary welding tables, pipe welding rotators, and automated fabrication systems. Controls a NEMA 23 stepper motor through a 1:108 drivetrain (NMRV030 + spur) with precise RPM control (0.001–3.0 RPM workpiece absolute limits in config.h; Motor Config stores a lower max RPM ceiling in NVS if desired).

Key Specs

Parameter Value
MCU ESP32-P4 (360MHz, dual-core RISC-V)
Display GUITION JC4880P443C, 800x480 landscape, MIPI-DSI ST7701S
Touch GT911 capacitive
UI Framework LVGL 9.5.0
Motor Driver FastAccelStepper 0.33.x (RMT hardware pulses)
Gear Ratio 1:108 total (60 x 72/40, NMRV030 + spur)
Microstepping 1/4, 1/8, 1/16, 1/32 (selectable)
RPM Range 0.001 – 3.0 RPM (MIN_RPM/MAX_RPM); UI max ≤ cap via Motor Config (NVS). Roadmap: higher limits with DM542T
Storage NVS (Preferences) + ArduinoJson blobs cfg / prs (16 presets, settings); one-time LittleFS import
Cross-core std::atomic with explicit memory ordering; single source of truth in src/app_state.h

Repository Structure

src/
  main.cpp              - FreeRTOS task setup
  config.h              - All hardware pins and motor parameters
  motor/                - FastAccelStepper wrapper, speed control, microstepping
  control/              - State machine, 5 welding modes
  safety/               - E-STOP ISR + watchdog
  storage/              - NVS persistence (+ legacy LittleFS migration)
  ui/                   - LVGL screens, display init, touch, theme
docs/
  images/               - SVG wiring diagrams, UI mockups
wiki/                   - GitHub Wiki pages

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