"""
Pin Locator for KiCad Schematics
Discovers pin locations on symbol instances, accounting for position, rotation, and mirroring.
Uses S-expression parsing to extract pin data from symbol definitions.
"""
import logging
import math
from pathlib import Path
from typing import List, Tuple, Optional, Dict
import sexpdata
from sexpdata import Symbol
from skip import Schematic
logger = logging.getLogger('kicad_interface')
class PinLocator:
"""Locate pins on symbol instances in KiCad schematics"""
def __init__(self):
"""Initialize pin locator with empty cache"""
self.pin_definition_cache = {} # Cache: "lib_id:symbol_name" -> pin_data
@staticmethod
def parse_symbol_definition(symbol_def: list) -> Dict[str, Dict]:
"""
Parse a symbol definition from lib_symbols to extract pin information
Args:
symbol_def: S-expression list representing symbol definition
Returns:
Dictionary mapping pin number -> pin data:
{
"1": {"x": 0, "y": 3.81, "angle": 270, "length": 1.27, "name": "~", "type": "passive"},
"2": {"x": 0, "y": -3.81, "angle": 90, "length": 1.27, "name": "~", "type": "passive"}
}
"""
pins = {}
def extract_pins_recursive(sexp):
"""Recursively search for pin definitions"""
if not isinstance(sexp, list):
return
# Check if this is a pin definition
if len(sexp) > 0 and sexp[0] == Symbol('pin'):
# Pin format: (pin type shape (at x y angle) (length len) (name "name") (number "num"))
pin_data = {
'x': 0,
'y': 0,
'angle': 0,
'length': 0,
'name': '',
'number': '',
'type': str(sexp[1]) if len(sexp) > 1 else 'passive'
}
# Extract pin attributes
for item in sexp:
if isinstance(item, list) and len(item) > 0:
if item[0] == Symbol('at') and len(item) >= 3:
pin_data['x'] = float(item[1])
pin_data['y'] = float(item[2])
if len(item) >= 4:
pin_data['angle'] = float(item[3])
elif item[0] == Symbol('length') and len(item) >= 2:
pin_data['length'] = float(item[1])
elif item[0] == Symbol('name') and len(item) >= 2:
pin_data['name'] = str(item[1]).strip('"')
elif item[0] == Symbol('number') and len(item) >= 2:
pin_data['number'] = str(item[1]).strip('"')
# Store by pin number
if pin_data['number']:
pins[pin_data['number']] = pin_data
# Recurse into sublists
for item in sexp:
if isinstance(item, list):
extract_pins_recursive(item)
extract_pins_recursive(symbol_def)
return pins
def get_symbol_pins(self, schematic_path: Path, lib_id: str) -> Dict[str, Dict]:
"""
Get pin definitions for a symbol from the schematic's lib_symbols section
Args:
schematic_path: Path to .kicad_sch file
lib_id: Library identifier (e.g., "Device:R", "MCU_ST_STM32F1:STM32F103C8Tx")
Returns:
Dictionary mapping pin number -> pin data
"""
# Check cache
cache_key = f"{schematic_path}:{lib_id}"
if cache_key in self.pin_definition_cache:
logger.debug(f"Using cached pin data for {lib_id}")
return self.pin_definition_cache[cache_key]
try:
# Read schematic
with open(schematic_path, 'r', encoding='utf-8') as f:
sch_content = f.read()
sch_data = sexpdata.loads(sch_content)
# Find lib_symbols section
lib_symbols = None
for item in sch_data:
if isinstance(item, list) and len(item) > 0 and item[0] == Symbol('lib_symbols'):
lib_symbols = item
break
if not lib_symbols:
logger.error("No lib_symbols section found in schematic")
return {}
# Find the specific symbol definition
for item in lib_symbols[1:]: # Skip 'lib_symbols' itself
if isinstance(item, list) and len(item) > 1 and item[0] == Symbol('symbol'):
symbol_name = str(item[1]).strip('"')
if symbol_name == lib_id:
# Found the symbol, parse pins
pins = self.parse_symbol_definition(item)
self.pin_definition_cache[cache_key] = pins
logger.info(f"Extracted {len(pins)} pins from {lib_id}")
return pins
logger.warning(f"Symbol {lib_id} not found in lib_symbols")
return {}
except Exception as e:
logger.error(f"Error getting symbol pins: {e}")
import traceback
logger.error(traceback.format_exc())
return {}
@staticmethod
def rotate_point(x: float, y: float, angle_degrees: float) -> Tuple[float, float]:
"""
Rotate a point around the origin
Args:
x: X coordinate
y: Y coordinate
angle_degrees: Rotation angle in degrees (counterclockwise)
Returns:
(rotated_x, rotated_y)
"""
if angle_degrees == 0:
return (x, y)
angle_rad = math.radians(angle_degrees)
cos_a = math.cos(angle_rad)
sin_a = math.sin(angle_rad)
rotated_x = x * cos_a - y * sin_a
rotated_y = x * sin_a + y * cos_a
return (rotated_x, rotated_y)
def get_pin_location(self, schematic_path: Path, symbol_reference: str,
pin_number: str) -> Optional[List[float]]:
"""
Get the absolute location of a pin on a symbol instance
Args:
schematic_path: Path to .kicad_sch file
symbol_reference: Symbol reference designator (e.g., "R1", "U1")
pin_number: Pin number/identifier (e.g., "1", "2", "GND", "VCC")
Returns:
[x, y] absolute coordinates of the pin, or None if not found
"""
try:
# Load schematic with kicad-skip to get symbol instance
sch = Schematic(str(schematic_path))
# Find the symbol instance
target_symbol = None
for symbol in sch.symbol:
ref = symbol.property.Reference.value
if ref == symbol_reference:
target_symbol = symbol
break
if not target_symbol:
logger.error(f"Symbol {symbol_reference} not found in schematic")
return None
# Get symbol position and rotation
symbol_at = target_symbol.at.value
symbol_x = float(symbol_at[0])
symbol_y = float(symbol_at[1])
symbol_rotation = float(symbol_at[2]) if len(symbol_at) > 2 else 0.0
# Get symbol lib_id
lib_id = target_symbol.lib_id.value if hasattr(target_symbol, 'lib_id') else None
if not lib_id:
logger.error(f"Symbol {symbol_reference} has no lib_id")
return None
logger.debug(f"Symbol {symbol_reference}: pos=({symbol_x}, {symbol_y}), rot={symbol_rotation}, lib_id={lib_id}")
# Get pin definitions for this symbol
pins = self.get_symbol_pins(schematic_path, lib_id)
if not pins:
logger.error(f"No pin definitions found for {lib_id}")
return None
# Find the requested pin
if pin_number not in pins:
logger.error(f"Pin {pin_number} not found on {symbol_reference}. Available pins: {list(pins.keys())}")
return None
pin_data = pins[pin_number]
# Get pin position relative to symbol origin
pin_rel_x = pin_data['x']
pin_rel_y = pin_data['y']
logger.debug(f"Pin {pin_number} relative position: ({pin_rel_x}, {pin_rel_y})")
# Apply symbol rotation to pin position
if symbol_rotation != 0:
pin_rel_x, pin_rel_y = self.rotate_point(pin_rel_x, pin_rel_y, symbol_rotation)
logger.debug(f"After rotation {symbol_rotation}°: ({pin_rel_x}, {pin_rel_y})")
# Calculate absolute position
abs_x = symbol_x + pin_rel_x
abs_y = symbol_y + pin_rel_y
logger.info(f"Pin {symbol_reference}/{pin_number} located at ({abs_x}, {abs_y})")
return [abs_x, abs_y]
except Exception as e:
logger.error(f"Error getting pin location: {e}")
import traceback
logger.error(traceback.format_exc())
return None
def get_all_symbol_pins(self, schematic_path: Path, symbol_reference: str) -> Dict[str, List[float]]:
"""
Get locations of all pins on a symbol instance
Args:
schematic_path: Path to .kicad_sch file
symbol_reference: Symbol reference designator (e.g., "R1", "U1")
Returns:
Dictionary mapping pin number -> [x, y] coordinates
"""
try:
# Load schematic
sch = Schematic(str(schematic_path))
# Find symbol
target_symbol = None
for symbol in sch.symbol:
if symbol.property.Reference.value == symbol_reference:
target_symbol = symbol
break
if not target_symbol:
logger.error(f"Symbol {symbol_reference} not found")
return {}
# Get lib_id
lib_id = target_symbol.lib_id.value if hasattr(target_symbol, 'lib_id') else None
if not lib_id:
logger.error(f"Symbol {symbol_reference} has no lib_id")
return {}
# Get pin definitions
pins = self.get_symbol_pins(schematic_path, lib_id)
if not pins:
return {}
# Calculate location for each pin
result = {}
for pin_num in pins.keys():
location = self.get_pin_location(schematic_path, symbol_reference, pin_num)
if location:
result[pin_num] = location
logger.info(f"Located {len(result)} pins on {symbol_reference}")
return result
except Exception as e:
logger.error(f"Error getting all symbol pins: {e}")
return {}
if __name__ == '__main__':
# Test pin location discovery
import sys
sys.path.insert(0, '/home/chris/MCP/KiCAD-MCP-Server/python')
from pathlib import Path
from commands.component_schematic import ComponentManager
from commands.schematic import SchematicManager
import shutil
print("=" * 80)
print("PIN LOCATOR TEST")
print("=" * 80)
# Create test schematic with components
test_path = Path('/tmp/test_pin_locator.kicad_sch')
template_path = Path('/home/chris/MCP/KiCAD-MCP-Server/python/templates/template_with_symbols_expanded.kicad_sch')
shutil.copy(template_path, test_path)
print(f"\n✓ Created test schematic: {test_path}")
# Add some components
print("\n[1/4] Adding test components...")
sch = SchematicManager.load_schematic(str(test_path))
# Add resistor at (100, 100), rotation 0
r1_def = {'type': 'R', 'reference': 'R1', 'value': '10k', 'x': 100, 'y': 100, 'rotation': 0}
ComponentManager.add_component(sch, r1_def, test_path)
# Add capacitor at (150, 100), rotation 90
c1_def = {'type': 'C', 'reference': 'C1', 'value': '100nF', 'x': 150, 'y': 100, 'rotation': 90}
ComponentManager.add_component(sch, c1_def, test_path)
SchematicManager.save_schematic(sch, str(test_path))
print(" ✓ Added R1 and C1")
# Test pin locator
print("\n[2/4] Testing pin location discovery...")
locator = PinLocator()
# Find R1 pins
r1_pin1 = locator.get_pin_location(test_path, "R1", "1")
r1_pin2 = locator.get_pin_location(test_path, "R1", "2")
print(f" R1 pin 1: {r1_pin1}")
print(f" R1 pin 2: {r1_pin2}")
# Find C1 pins (rotated 90 degrees)
c1_pin1 = locator.get_pin_location(test_path, "C1", "1")
c1_pin2 = locator.get_pin_location(test_path, "C1", "2")
print(f" C1 pin 1: {c1_pin1}")
print(f" C1 pin 2: {c1_pin2}")
# Test get all pins
print("\n[3/4] Testing get all pins...")
r1_all_pins = locator.get_all_symbol_pins(test_path, "R1")
print(f" R1 all pins: {r1_all_pins}")
c1_all_pins = locator.get_all_symbol_pins(test_path, "C1")
print(f" C1 all pins: {c1_all_pins}")
# Verify results
print("\n[4/4] Verification...")
success = True
if not r1_pin1 or not r1_pin2:
print(" ✗ Failed to locate R1 pins")
success = False
else:
print(" ✓ R1 pins located")
if not c1_pin1 or not c1_pin2:
print(" ✗ Failed to locate C1 pins")
success = False
else:
print(" ✓ C1 pins located")
# Check rotation (C1 pins should be rotated 90 degrees from R1)
if r1_pin1 and c1_pin1:
# R1 is not rotated, pins should be at y offset from symbol center
# C1 is rotated 90°, pins should be at x offset from symbol center
print(f"\n Pin offset analysis:")
print(f" R1 (0°): pin 1 y-offset = {r1_pin1[1] - 100}")
print(f" C1 (90°): pin 1 x-offset = {c1_pin1[0] - 150}")
print("\n" + "=" * 80)
if success:
print("✅ PIN LOCATOR TEST PASSED!")
else:
print("❌ PIN LOCATOR TEST FAILED!")
print("=" * 80)
print(f"\nTest schematic saved: {test_path}")
