Kicad Schematic

KiCAD Schematic Design Workflow

This skill guides Claude to design schematics using Konnect MCP tools.

ALL modifications go through MCP tools — never edit .kicad_sch files directly.

Toolset Loading

Before any schematic work, load the required toolsets:

load_toolset('sch_components')   # place, move, rotate, delete symbols
load_toolset('sch_wiring')       # wires, net labels, power symbols, connections

Load additional toolsets as needed:

load_toolset('library')          # search_symbols, get_symbol_info, list_symbol_libraries
load_toolset('sch_batch')        # batch operations for 3+ items
load_toolset('sch_analysis')     # find components, get pin info, inspect nets

Always call get_active_toolsets() first to see what is already loaded.

Component Placement

Workflow

• Search the library first: use search_symbols to find the correct lib_id
• Get pin info: use get_symbol_info to see pin names, numbers, and positions
• Place on the 1.27mm grid (KiCAD default schematic grid)
• Verify placement with list_schematic_components

Common Library IDs

| Component | lib_id |

|------------------|---------------------------------|

| Resistor | Device:R |

| Capacitor | Device:C |

| Capacitor Polar | Device:C_Polarized |

| Inductor | Device:L |

| LED | Device:LED |

| Diode | Device:D |

| Zener | Device:D_Zener |

| NPN Transistor | Device:Q_NPN_BCE |

| PNP Transistor | Device:Q_PNP_BCE |

| N-MOSFET | Device:Q_NMOS_GDS |

| P-MOSFET | Device:Q_PMOS_GDS |

| 2-pin Connector | Connector_Generic:Conn_01x02 |

| 4-pin Connector | Connector_Generic:Conn_01x04 |

| Ground | power:GND |

| +3.3V | power:+3V3 |

| +5V | power:+5V |

| VCC | power:VCC |

| VDD | power:VDD |

Rotation Conventions

• 0 degrees: default orientation (pins left/right)
• 90 degrees: rotated CCW (useful for vertical components)
• 180 degrees: flipped horizontally
• 270 degrees: rotated CW

Power symbols: GND uses 0 (arrow points down), VCC/VDD/+3V3/+5V use 0 (arrow points up).

Spacing Guidelines

• Between ICs: 30-50mm horizontal, 20-30mm vertical
• Between passive components: 10-15mm
• Between a decoupling cap and its IC: 5-10mm
• Leave room for wiring: minimum 5mm between component pins and other elements

Wiring

Connection Methods — Decision Table

| Scenario | Method | Why |

|-----------------------------------------|-------------------------|------------------------------------------|

| Two pins physically close (<30mm) | connect_pins | Direct wire, auto-routed |

| Named signal (SDA, MOSI, EN, etc.) | connect_to_net | Stub wire + net label, cleaner |

| Power rail (VCC, GND, +3V3) | add_power_symbol | Proper power symbol, auto-connects |

| Bus signals (D0-D7) | connect_to_net | Net labels with bus naming |

| Cross-sheet signal | Global label | Connects across schematic sheets |

| Multiple pins to same net (3+) | batch_connect_to_net | Efficient bulk operation |

connect_pins

Use for direct pin-to-pin connections. The tool auto-routes with L-bends.

connect_pins(from_component, from_pin, to_component, to_pin)

• Specify pins by pin number (from get_schematic_pin_locations)
• Works best when pins are nearby and facing each other
• Automatically creates wire segments with proper bends

connect_to_net

Use for named nets. Creates a short stub wire and attaches a net label.

connect_to_net(component_reference, pin_number, net_name)

• Preferred for signals that connect to 3+ pins
• Preferred for named buses and control signals
• Keeps schematic clean and readable
• Net name must be consistent across all connections

add_power_symbol

Use for all power connections. Never manually wire to power symbols.

add_power_symbol(component_reference, pin_number, power_net)

• Automatically places the correct power symbol (GND, VCC, etc.)
• Handles orientation automatically
• Connects the pin to the global power net

Batch Operations

Load sch_batch toolset when placing 3 or more components or making bulk connections.

batch_place_components

Place multiple components in one call. Provide schematic and a components array of {lib_id, x, y, rotation?, reference?, value?, unit?} objects. Pass reference explicitly for each component -- it is not auto-assigned.

batch_connect_to_net

Connect multiple pins to the same net in one call. Ideal for:

• Connecting all VCC pins on an IC
• Connecting all GND pins
• Bus signals across multiple ICs

batch_edit_schematic_components

Bulk-modify component properties (values, footprints, fields) across multiple components.

When to Use Batch vs Individual

• 1-2 components: individual calls
• 3+ components: batch operations
• Mixed operations (place + wire): do placement batch first, then wiring batch

Common Patterns

Decoupling Capacitor

Place 100nF cap (Device:C) within 5mm of IC power pin. Connect one pin to VCC via power symbol, other pin to GND via power symbol. One cap per VCC/VDD pin.

Pull-up Resistor

Place resistor (Device:R) vertically. Connect one pin to the signal net via connect_to_net, other pin to VCC via add_power_symbol. Typical values: 4.7k for I2C, 10k for general.

Voltage Divider

Two resistors in series, vertically aligned. Top to input net, middle junction to output net, bottom to GND. Use connect_to_net for input/output, add_power_symbol for GND.

LED with Current-Limiting Resistor

Resistor in series with LED. Connect resistor to signal/power, resistor to LED anode, LED cathode to GND. R = (Vsupply - Vf) / If. Typical: 330R for 3.3V, 470R for 5V.

Bypass/Decoupling Filter

For analog circuits: 100nF ceramic + 10uF electrolytic in parallel, close to power pins. Place ceramic closest to IC.

Crystal Oscillator

Crystal (Device:Crystal) between XI and XO pins. Two load capacitors from each crystal pin to GND. Typical load caps: 12-22pF. Optional 1M feedback resistor across crystal.

Post-Placement Verification

After placing components and wiring, always run these checks:

annotate_schematic

Assigns reference designators (R1, C1, U1, etc.) to all unannotated components. Run after all placement is complete.

validate_wire_connections

Checks that all wires connect properly to pins. Reports:

• Dangling wire ends
• Wires that miss pins
• Overlapping wires

validate_component_connections

Verifies that components have the expected connections. Reports:

• Unconnected pins that should be connected
• Missing power connections

find_orphan_items

Finds floating wires, labels, and symbols that are not connected to anything.

Verification Workflow

• Place all components
• Complete all wiring
• Run annotate_schematic
• Run validate_wire_connections
• Run validate_component_connections
• Run find_orphan_items
• Fix any reported issues
• Save with save_project

Rules

• Never edit .kicad_sch files directly — all changes go through MCP tools
• Never guess pin numbers — always use get_schematic_pin_locations or get_symbol_info to look up pin numbers before connecting
• Always verify after changes — run validation tools after placing and wiring
• Use the grid — all placements on 1.27mm grid
• Search before placing — use search_symbols to confirm lib_id exists
• Power symbols for power — never manually wire power connections
• Net labels for named signals — keeps schematics readable
• Save frequently — call save_project after major operations
• Load toolsets first — check get_active_toolsets() and load what you need before starting

10. Batch for bulk — use batch toolset for 3+ repetitive operations