Breadboard Layout¶

Experimental

The breadboard layout currently draws a TMC2209 stepstick on a Raspberry Pi 4 or 5. Other boards and module types fail with an error. The schematic layout is unchanged and remains the default.

Overview¶

layout: breadboard draws the board artwork beside an upright solderless breadboard. Plug-in modules sit on its holes and colored jumper wires run between the real pins.

title: "TMC2209 on a breadboard"
board: raspberry_pi_4
layout: breadboard
show_legend: true
devices:
  - type: breadboard_rail
    name: Rails
  - type: tmc2209
    name: D1
connections:
  - {board_pin: 1, device: Rails, device_pin: "+3V3"}
  - {board_pin: 36, device: D1, device_pin: STEP}
  - from: {device: Rails, device_pin: "+3V3"}
    to: {device: D1, device_pin: MS1}

See examples/breadboard_stepstick.yaml for a complete example.

TMC2209 on a breadboard

A full build with three stepsticks, NEMA 17 motors, a 24 V supply and a smoothing capacitor (examples/breadboard_three_motors.yaml):

Three stepper motors on a breadboard

Dark theme (theme: dark) is supported too: see docs/assets/breadboard/three-motors-dark.svg.

Devices¶

Type	Default role	Notes
`tmc2209`	`module`	16-pin stepstick straddling the trench (BIGTREETECH V1.3 pin order)
`nema17`	`motor`	Four coil leads, drawn beside its module
`psu_24v`	`supply`	Motor supply, feeds the `+24V` and `MGND` rails
`electrolytic`	`capacitor`	Polarized; plugs into two rails with the stripe on the negative leg
`breadboard_rail`	`rail`	`GND`, `+3V3`, `MGND`, `+24V` strips

Each device takes its role from its type. Override it, or pin a module to a row, with a breadboard key:

- type: tmc2209
  name: D2
  breadboard: {row: 16}   # first pin row; rows must be at least 8 apart and start at 3 or later

A custom inline device has no type to infer a role from, so it must set one. A custom motor works with any pin names; supply expects pins +V/-V and capacitor expects +/-:

- name: Pump motor
  breadboard: {role: motor}
  pins:
    - {name: A, role: GPIO}
    - {name: B, role: GPIO}

Behavior¶

Modules stack top to bottom in YAML order. List them in header order to keep wire ribbons from crossing.
theme and show_legend are honored. show_legend draws the same "Device Specifications" table as the schematic layout.
The title, header pin-number circles, wire styling and font sizes match the schematic layout. Labels use pin names as written in the device configs (+3V3, MGND, +24V).
Each header pin that carries a wire gets a small tag with its net (STEP m2, GND, +3V3), in the schematic's pin-label style, next to its own pin. The supply box shows the rail each terminal feeds (-V GND, +V 24V).
A wire without color takes the default color for its pin role.
Logic ground and motor ground rails are tied at the bottom of the board when motor ground is used.

Errors¶

Rendering fails with a message for: a board that is not a Pi-style 40-pin header, a device type the layout cannot draw, overlapping or too-high module rows, a capacitor missing a leg, and any device with no connection.

External power¶

The motor supply pins (psu_24v.+V, tmc2209.VM, the +24V rail) use the EXT_POWER pin role. Validation reports an error if one is connected to a board 3V3 or 5V pin.

MCP server¶

Not available through the MCP server. Prompt-based generation always produces the schematic layout, and the MCP device database is a separate curated list that does not include these parts.