Contents

Introduction 1. Theory of Operation 1.1. Background 1.2. Peripherals Used 1.3. Application Overview 2. Hardware Configuration 2.1. Microcontroller 2.2. CNC Gantry 2.3. End Effector 2.4. Stepper Motors 2.5. Limit Switches 2.6. UART to USB Bridge 2.7. Pinout 3. Motion Control Overview 3.1. Common Software-Only Method 3.2. Numerically Controlled Oscillator (NCO) Divisor 3.3. CNC Acceleration Operation 3.4. CNC Head Travel Logic 4. Control Logic 4.1. G-Code 4.2. Configuration Communication 4.2.1. Info Size 4.2.2. Buffer Size 4.2.3. Ticks Per Meter 4.2.4. Max X and Y 4.2.5. Num Accel Points 4.2.6. Accel Points 4.3. Standard Communication 4.3.1. Standard Movement 4.3.2. Home 4.3.3. Raise or Lower Pin 4.3.4. End of Transmission 4.4. Buffer 5. Conclusion 6. Appendix A: Application Code 7. Appendix B: Application Schematic 8. Appendix C: Star G-Code The Microchip Website Product Change Notification Service Customer Support Microchip Devices Code Protection Feature Legal Notice Trademarks Quality Management System Worldwide Sales and Service