Add optional standard Y-axis coordinate system

Problem

KiCAD uses an inverted Y-axis (like computer graphics):

• Higher Y values = lower on screen (Y=120 is below Y=100)
• Lower Y values = higher on screen (Y=100 is above Y=120)

This is opposite from standard math/physics where +Y goes up. This creates several issues:

1. Cognitive load: Users must mentally flip coordinates when designing
2. LLM performance: Language models trained on standard coordinate systems struggle with inverted Y-axis
3. Code readability: Circuit descriptions like "place R2 below R1" require counter-intuitive higher Y values
4. Educational barrier: New users from math/science backgrounds find this confusing

Proposed Solution

Add a global configuration option to use standard Y-axis orientation:

import kicad_sch_api as ksa

# Enable standard Y-axis (higher Y = higher on screen)
ksa.config.positioning.use_standard_y_axis = True

# Now Y increases upward (like standard math)
sch.components.add('Device:R', 'R1', '10k', position=(100, 100))  # Higher on screen
sch.components.add('Device:R', 'R2', '10k', position=(100, 80))   # Lower on screen (smaller Y)

Implementation Details

When use_standard_y_axis = True:

1. All input Y coordinates are flipped before being written to KiCAD format
2. All output Y coordinates are flipped when reading from KiCAD format
3. The KiCAD file format remains unchanged (still uses inverted Y-axis)
4. Only affects the Python API interface

Technical Approach

Add Y-axis conversion in the core positioning methods:

def _convert_y(y: float, invert: bool = False) -> float:
    """Convert Y coordinate based on axis configuration."""
    if config.positioning.use_standard_y_axis:
        # Flip Y-axis to/from KiCAD's inverted system
        # Need a reference point - could use schematic bounds or origin
        return -y if invert else y
    return y

Benefits

1. Improved LLM performance: AI models can reason about circuits using standard coordinates
2. Better UX: More intuitive for users from math/science/engineering backgrounds
3. Backward compatible: Default behavior unchanged (inverted Y-axis matches KiCAD)
4. Educational: Easier to teach and learn circuit generation

Considerations

• Need to define a Y-axis origin/reference point for the flip
• Should work seamlessly with grid units
• All positioning methods must be updated consistently
• Documentation should explain both modes

Related

This complements existing positioning improvements:

• Grid units configuration (#existing-issue)
• Parametric positioning with p() helper
• Auto-routing API

Use Cases

Circuit generation by LLMs:

# LLM can now use natural language → standard coordinates
"Place R2 below R1"  → R2.y < R1.y  (standard Y-axis)
vs.
"Place R2 below R1"  → R2.y > R1.y  (inverted Y-axis - confusing!)

Educational examples:

# Draw voltage divider from top to bottom
sch.components.add('power:VCC', position=(50, 100))  # Top (high Y)
sch.components.add('Device:R', 'R1', position=(50, 80))
sch.components.add('Device:R', 'R2', position=(50, 60))
sch.components.add('power:GND', position=(50, 40))   # Bottom (low Y)
# Natural top-to-bottom ordering with decreasing Y values

Priority

Medium-High - This would significantly improve:

• AI/LLM-assisted circuit generation
• User experience for programmatic schematic creation
• Educational adoption of the library

Not urgent for current users who are accustomed to KiCAD conventions, but valuable for expanding the user base and AI applications.