V-Bot Climbing Gondola

A custom C++ ESP32 firmware for a V-Bot (Wall Plotter / Polargraph) climbing gondola. This project turns an ESP32-S3 SuperMini into a standalone wireless CNC controller for drawing large formats on walls or whiteboards.

Features

• Wall Plotter Kinematics: Converts standard cartesian Cartesian G-code (X/Y) into left/right string lengths.
• Standalone WiFi AP: Creates its own V-Bot WiFi network, no external router needed.
• Web Interface: Built-in web server for uploading G-Code, jogging motors, viewing logs, and sending commands.
• Accurate Motion Control: Uses AccelStepper for smooth, accelerated motor movements.
• G-Code parsing: Supports standard G-code commands (G0, G1, G4, M3, M5, etc.).
• Servo Pen Lift: Automatic Z-axis mapping to a PWM servo for lifting and lowering the pen.
• Persistent Settings: Configurable anchor widths, feed rates, and machine params saved to flash.
• Over-The-Air (OTA) Updates: Update firmware directly over WiFi using ElegantOTA.
• Status LED: NeoPixel integration for visual machine state (Idle, Running, Error).

Hardware Requirements

• ESP32-S3 SuperMini (or similar ESP32-S3 development board)
• Two Stepper Motors with drivers (e.g., A4988 / TMC2209)
• One standard RC Servo for the pen lift mechanism
• Power Supply (appropriate for your stepper motors)

Pinout (Default Configuration)

Refer to config.yaml or src/config.h to change these default pins.

• Left Motor (X): Step PIN: gpio.1, Dir PIN: gpio.2
• Right Motor (Y): Step PIN: gpio.4, Dir PIN: gpio.5
• Servo (Z / Pen): PWM PIN: gpio.6
• Stepper Enable: PIN gpio.7 (Active Low)

Installation & Flashing

This project is built using PlatformIO.

1. Clone or download the repository.
2. Open the project folder in VSCode with the PlatformIO extension installed.
3. Connect your ESP32-S3 SuperMini via USB.
4. Click the upload button (➔) in PlatformIO. Note: It will automatically install dependent libraries (AccelStepper, ArduinoJson, ESPAsyncWebServer, etc.).

Usage

1. Power On: Turn on the V-Bot. Wait a few seconds for it to boot.
2. Connect to WiFi: From your phone or computer, connect to the V-Bot network:
   • SSID: V-Bot
   • Password: vbot1234
3. Access WebUI: Open a web browser and navigate to http://192.168.4.1.
4. Calibration: Set your gondola on the wall. Use the Web UI to define the proper distance between your two top motor anchors.
5. Draw: Upload a .gcode file through the Web Interface to start plotting!

G-Code Generator

A standalone utility is provided in the repository to generate shapes and text:

• Open gcode_generator.html in any modern web browser.
• Adjust dimensions, center points, and settings.
• Export as standard .gcode and upload directly to your V-Bot.

Included sample files: square.gcode, circle.gcode.

FluidNC Similarity

While this firmware aims to be lightweight and specific to the V-Bot application, the configuration file structure (config.yaml) is modeled after the excellent FluidNC project to make it familiar for CNC enthusiasts.

License

Open Source / MIT License