Getting Started with Breadpad #

Welcome to Breadpad! This guide will walk you through creating your first circuit and running a simulation. In just a few minutes, you’ll be designing and analyzing circuits like a pro.

Your First Circuit: LED with Resistor #

Let’s build a simple LED circuit to learn the basics.

Step 1: Create a New Document #

Open Breadpad
Tap the + button (or File → New on Mac)
Choose “New Circuit”
You’ll see an empty breadboard

Step 2: Add a Voltage Source #

Look at the component toolbox on the left
Tap Voltage Source
Tap anywhere on the breadboard to place it
The voltage source occupies a 2×2 area

Step 3: Configure the Voltage #

Double-tap the voltage source
Set the voltage to 5V
Keep type as “DC”
Tap “Done”

Step 4: Add a Resistor #

Select Resistor from the toolbox
Place it near the voltage source
Double-tap to edit
Set resistance to 220Ω
This limits current to protect the LED

Step 5: Add a Diode (as LED) #

Select Diode from the toolbox
Place it near the resistor
Note the diode direction (arrow points to cathode)
This represents our LED

Step 6: Connect with Wires #

Select Wire from the toolbox
Tap the positive (red) terminal of voltage source
Tap one end of the resistor - wire connects automatically
Add another wire from resistor to diode anode
Final wire from diode cathode to voltage source negative

Your circuit is complete!

Step 7: Add Measurement Probes #

Tap any connection point to add a probe
Add one probe at the resistor-diode connection
Add another at the diode cathode
Probes appear as colored dots

Step 8: Run the Simulation #

Tap the Oscilloscope button (bottom toolbar)
Select Operating Point analysis
Tap Run Simulation
View the DC voltages at each probe point

What You Should See #

Voltage across the LED: ~2V (typical LED forward voltage)
Voltage across resistor: ~3V (5V - 2V)
Current through circuit: ~13.6mA ((5V - 2V) / 220Ω)

Understanding the Interface #

Component Toolbox (Left Side) #

Passive: Resistor, Capacitor, Inductor
Active: Transistor, Diode
Sources: Voltage/Current sources
Connections: Wire, Transmission Line
ICs: Chip (for custom parts)

Oscilloscope: Open analysis window
Undo/Redo: Correct mistakes
Zoom: Adjust view
Settings: Preferences and help

Breadboard Area #

Grid of tie points (holes)
Components snap to grid
Blue lines show connections
Red/Black for power rails

Common Beginner Tips #

Component Placement #

Components must align with tie points
Can’t overlap other components
Wires connect any two points
Double-tap to edit values

Making Connections #

Wires connect automatically
Can’t cross components
Use multiple wires for complex paths
Delete wires by selecting and pressing delete

Running Simulations #

Must have at least one voltage/current source
Add probes before running analysis
Different analyses show different results
Check probe colors match traces

Next Projects to Try #

1. RC Filter (5 minutes) #

Learn about frequency response:

Voltage source (AC, 1V, 1kHz)
Resistor (10kΩ) in series
Capacitor (10nF) to ground
Run AC Analysis to see filter response

2. Transistor Switch (10 minutes) #

Digital logic basics:

NPN transistor (2N3904)
Base resistor (10kΩ)
Collector resistor (1kΩ)
Switch voltage source between 0V and 5V
See LED turn on/off

3. 555 Timer (15 minutes) #

Classic astable oscillator:

Add 555 timer chip
Configure with resistors and capacitor
Run transient analysis
See square wave output

Platform-Specific Tips #

iPhone/iPad #

Pinch to zoom for detailed work
Long press for context menus
Shake to undo mistakes
Split View to reference documentation

Mac #

Keyboard shortcuts speed up workflow
Multiple windows for comparing circuits
Right-click for quick actions
Tab key navigates components

Vision Pro #

Look and pinch to place components
Hand gestures to manipulate view
Voice commands for values
Spatial layout for complex circuits

Troubleshooting #

“No DC path to ground” #

Every node needs a path to ground
Add a high-value resistor (10MΩ) if needed
Check all connections are complete

“Convergence failed” #

Simulation couldn’t find solution
Check component values are reasonable
Ensure sources are properly connected
Try simpler analysis first

“Component won’t place” #

Must align with tie points
Can’t overlap existing components
Some components have fixed sizes
Try different location

Learning Path #

Week 1: Basics #

Ohm’s Law circuits
Voltage dividers
Series/parallel combinations
DC analysis mastery

Week 2: Reactive Components #

RC circuits
RL circuits
Time constants
Transient analysis

Week 3: Semiconductors #

Diode circuits
Transistor biasing
Simple amplifiers
Switching circuits

Week 4: Advanced #

Op-amp circuits
Filters
Oscillators
Frequency analysis

Getting Help #

In-App Resources #

Tap component → “Learn More”
Settings → Help
Example circuits (coming soon)

Online Resources #

Community #

Pro Tips #

Save Often: Although auto-save is active, manual saves create restore points
Name Circuits: Use descriptive names for easy finding
Use Folders: Organize projects in iCloud Drive
Check Values: Double-check component values before simulation
Start Simple: Build complexity gradually
Learn SPICE: Understanding basics helps debug issues

Ready for More? #

You’ve completed your first circuit! Here’s what to explore next:

Advanced Features - Game controllers, annotations
Import/Export - Use existing SPICE files
Premium Features - Unlock full potential

Remember: Every expert was once a beginner. Keep experimenting, and you’ll be designing complex circuits in no time!

Quick Reference Card #

Essential Shortcuts (Mac) #

⌘N: New circuit
⌘S: Save
⌘Z: Undo
Space: Pan mode
Delete: Remove selected

Touch Gestures (iOS/iPadOS) #

Tap: Select/Place
Double-tap: Edit
Pinch: Zoom
Two fingers: Pan
Long press: Options

Happy circuit building! 🔌