Manual on Breadpad

The Workspace

Thu, 09 Jul 2026 00:00:00 +0000

The Workspace #

The board #

The breadboard has 17 rows, top to bottom:

GND and VCC power rails (top pair)
Signal rows J, I, H, G, F
The center divide — the channel chips straddle
Signal rows E, D, C, B, A
GND and VCC power rails (bottom pair)

As on a physical board, each vertical 5-hole strip (J–F above the divide, E–A below) is one electrical node; the rails run horizontally, with the usual break in the rail every six columns. Tie points are labeled letter + column (“A5”, “J12”); rail holes are labeled GND/V with the column.

Building Circuits

Thu, 09 Jul 2026 00:00:00 +0000

Building Circuits #

The tool palette #

The floating bar at the bottom holds every tool. On narrow screens five show directly — Oscilloscope, Wire, Resistor, Capacitor, Voltage Source — and the rest live in a More tools slot that always surfaces the armed tool’s icon.

Each tool has a single-letter shortcut (no modifier), also listed in the Tools menu on Mac:

Key	Tool	Key	Tool
V	Select	L	Inductor
P	Oscilloscope (probe)	I	Chip
W	Wire	S	Voltage Source
R	Resistor	T	Transistor
C	Capacitor	X	Transmission Line
D	Diode

Tapping the armed tool again returns to Select.

Part Libraries

Thu, 09 Jul 2026 00:00:00 +0000

Part Libraries #

Chips, transistors, and diodes are chosen from bundled part libraries. Each picker works the same way: a search field (matches part numbers and descriptions), a Category filter menu, and infinite scrolling through the results. Open a picker by arming the Chip/Transistor/Diode tool and tapping the board, or from Choose from Library inside a part’s editor.

What’s in the libraries #

Chips (260+) — every part is a real SPICE subcircuit:

Simulating

Thu, 09 Jul 2026 00:00:00 +0000

Simulating #

Breadpad runs your circuit through ngspice, the standard open-source SPICE engine — the same numerical models used in professional EDA tools.

Probes #

Arm the Oscilloscope tool (P) and tap tie points to drop measurement probes; tap a probed hole again to remove it. Probes record the voltage at their node.

The free tier plots signals from up to 2 probes; Premium plots them all.

The oscilloscope pill #

The pill in the toolbar shows your probe count and — once at least one probe is placed — a live sparkline: a continuously running background simulation of your circuit, updating as you edit. A warning badge on the pill means the live run hit a simulation error.

SPICE Netlists

Thu, 09 Jul 2026 00:00:00 +0000

SPICE Netlists #

Everything on the breadboard is a SPICE netlist — Breadpad generates it from your placed parts, and you can always drop down to the text.

The SPICE Shell #

Open SPICE Shell from the oscilloscope menu to see the current breadboard’s full netlist in a syntax-aware editor. Node names follow the board: GND, VCC1, VCC2 for the rails, and column-based names for the signal strips.

Documents & Export

Thu, 09 Jul 2026 00:00:00 +0000

Documents & Export #

Creating documents #

The launch screen (iPhone, iPad, Vision Pro) has two buttons: New Breadboard and New Netlist. Each opens a template picker — Empty at the top, then the bundled example library. On Mac, use ⌘N and the standard document browser.

Documents are files: they live in Files/iCloud Drive, sync across devices, and support the system version browser, rename, duplicate, and share.

The example library #

Examples are grouped into chapters that follow a classic electronics curriculum, from basics to complete systems: