Electronic-Toolbox - Software user guide
1. About Electronic-Toolbox 2
Welcome to Electronic-Toolbox 2, your comprehensive companion for electronics design, reference, and calculation. Whether you’re a professional engineer, a student in electronics or electrical engineering, a hobbyist tinkering in your workshop, or a radio amateur (HAM) needing quick access to tools and data, this app brings together over 100 essential tools and resources in one place. From resistor color code decoders and coil calculators to pinout references for boards like Raspberry Pi and Arduino, frequency tables, and interactive visualizations like battery charge curves—everything is designed for fast, reliable use in the lab, classroom, or field.
Electronic-Toolbox has been a trusted staple since 2009, evolving through years of user feedback to become one of the most complete electronics apps available. With Electronic-Toolbox 2, we introduce a fully modernized edition that honors this legacy while embracing new possibilities. Originally envisioned as a major update to the classic Electronic-Toolbox Pro, the project grew into a standalone app due to its scope: a complete overhaul of the interface, tools, and platform support, all while preserving the familiar workflow that users have relied on for over a decade.
1.1. Why a New Version?
The original Electronic-Toolbox Pro remains fully available and usable—it’s not being replaced or deprecated. We chose to create Electronic-Toolbox 2 as a gentle evolution for several key reasons:
Modern Platform Support: Electronic-Toolbox 2 is now a Universal App available on iOS as well as on Mac. Settings and favorites sync seamlessly via iCloud across devices, making it easier to switch between your phone in the workshop and your Mac at your desk.
Enhanced Usability: We’ve introduced multi-window support on Mac for side-by-side tool use, pinned favorites for quick access in the sidebar, and interactive elements (like dynamic graphs in the Battery Charge tool) to make calculations more intuitive and visual. The redesigned UI includes Dark Mode and a cleaner structure, without disrupting established habits.
Continued Reliability: All core tools from the original app are included and refined—nothing is lost, and much is improved for precision and speed. Features like PDF export for documentation and offline functionality ensure it’s as dependable as ever.
Future-Proof Foundation: Built with the latest technologies, Electronic-Toolbox 2 is optimized for years of updates and expansions. While advanced features like the Circuit Editor and project management remain exclusive to Electronic-Toolbox Pro for now, they can still be accessed alongside this new edition.
This new version isn’t about starting over—it’s about carrying forward what works, refined for today’s workflows. If you’re new to the series, you’ll find a powerful, all-in-one toolkit. If you’re upgrading from the original, the transition feels natural: familiar tools, now even better.
We — Jan and Marcus Roskosch — developed Electronic-Toolbox 2 with the same passion that launched the original app. Your feedback has shaped it every step of the way, and we invite you to explore, use, and suggest improvements as we continue building the best electronics companion possible.
1.2. Troubleshooting
In case of problems, please use the Contact Developer feature inside the App’s settings to contact me and I will be happy to help.
2. Using the App
Electronic-Toolbox 2 is a universal app built for iPhone, iPad, and Mac. It’s a one-time purchase that works seamlessly across all your Apple devices, with settings and favorites syncing automatically via iCloud.
The app is organized into five main sections, plus an optional Pinned section that appears when you’ve added favorite tools for quick access:
Search – Quickly find any tool, calculation, or component across the entire app
Calculations – A comprehensive collection of calculation tools organized by category: - Passive Components (resistors, capacitors, inductors) - Active Components (transistors, diodes) - Circuit Analysis - Power & Energy - Wiring & Cables - Basic Laws (Ohm’s law, etc.) - Conversion Tools
Tools – Specialized tools including oscilloscope, frequency counter, and tone generators
Resources – Reference materials and databases: - Semiconductors - Integrated Circuits - Development Boards (Arduino, Raspberry Pi, etc.) - Components - General Reference
Pinned – Your favorite tools for instant access (appears automatically when you pin tools)
Settings – Customize the app’s appearance and behavior
2.1. Navigating the App
On Mac:
The sidebar is always visible on the left side of the main window, showing all available sections. Click any section to view its contents in the main area.
The Mac interface with permanent sidebar navigation
Multi-Window Support: Press ⌘ + N to open additional windows. This lets you view multiple tools side-by-side—perfect for comparing calculations or referencing data while working with another tool.
Accessing Settings: Click the Settings button at the bottom of the sidebar, or use the standard macOS keyboard shortcut ⌘ + , (Command-Comma), or select Electronic-Toolbox > Settings from the menu bar.
On iPad:
The sidebar appears on the left side of the screen. Tap any section to view its tools and calculations.
The iPad interface with collapsible sidebar
Showing/Hiding the Sidebar: If the sidebar is hidden, tap the sidebar icon (☰) in the upper-left corner to reveal it. This is especially useful in portrait orientation to maximize screen space.
Accessing Settings: Tap the Settings button at the bottom of the sidebar.
On iPhone:
Navigation uses a compact list view. From the main screen, tap any section to explore its contents.
The iPhone main navigation screen
Going Back: Use the back button (←) in the upper-left corner to return to the main navigation screen.
Accessing Settings: Scroll to the bottom of the main screen and tap the Settings button.
2.2. Working with Tools
Pinning Favorite Tools
Frequently used tools can be pinned for quick access. When you pin a tool, it appears directly in the sidebar (iPad/Mac) or main screen (iPhone), eliminating the need to navigate through categories.
To pin a tool, tap the pin icon (📌) while viewing any tool. Pinned tools sync across all your devices via iCloud.
Using Search
The Search section provides instant access to any tool or component in the app. Simply:
Tap Search in the sidebar
Enter keywords like “resistor,” “voltage divider,” or “Arduino”
Tap any result to open that tool or component
Search looks across tool names, descriptions, and component databases, making it the fastest way to find what you need.
Calculations vs. Tools vs. Resources
Calculations are interactive tools where you input values and get instant results (e.g., Ohm’s Law calculator, voltage divider)
Tools are specialized utilities like oscilloscope, frequency counter, and signal generators
Resources are reference materials and databases you can browse or search (e.g., pinout diagrams, component specifications)
2.3. Settings and Customization
Access Settings to customize your experience:
Display Preferences - Notation: Choose between American notation (V for voltage) or European notation (U for voltage) - Component Style: Select ANSI or IEC symbols for circuit diagrams
iCloud Sync Settings and pinned tools automatically sync across your devices when iCloud is enabled.
Support - View the complete manual - Visit the website for updates and information - Contact the developer for assistance - Discover more apps by Jan and Marcus Roskosch
1. Working with Calculation Tools
Electronic-Toolbox 2 includes over 50 calculation tools for electronics design and analysis. While each tool serves a specific purpose—from Ohm’s Law and voltage dividers to complex circuits like NE555 timers and operational amplifiers — they all share a common, intuitive interface designed for efficiency and ease of use.
This chapter explains the shared features and interactions you’ll encounter across all calculation tools.
1.1. Overview of Calculation Tools
Calculation tools are organized into several categories:
Circuit Calculations – Tools for analyzing and designing circuits (voltage dividers, NE555 timers, op-amps, transistor circuits, etc.)
Formula Calculations – Basic electronic formulas (Ohm’s Law, LED circuits, reactance, power factor, etc.)
Single Purpose Tools – Specialized calculators (coils, transformers, PCB trace width, battery charge, etc.)
Code Conversions – Decode and encode component markings (resistor color codes, capacitor codes, inductor codes, etc.)
Unit Conversions – Convert between different units and standards
Each tool automatically saves your inputs and settings, so when you return to a tool, it resumes exactly where you left off.
1.2. Entering Parameter Values
Interactive Input Fields
Each tool displays its parameters in clearly labeled input fields showing:
Calculation input field showing the parameter name, mathematical symbol, input field, E-Series button and unit selector
Mathematical symbol (e.g., V, R, f) – Displayed in proper mathematical notation
Parameter name (e.g., “Input Voltage”, “Resistor 1”, “Frequency”)
Input field – For entering values
E-Series button – To choose the E-Series value
Unit selector – To choose the measurement unit
Flexible Input Formats
The app understands multiple input formats, making data entry fast and natural:
Standard notation:
1000 → 1000
0.001 → 0.001
Engineering notation:
1.5e3 → 1500
4.7e-6 → 0.0000047
SI prefixes (standard):
1k → 1000
4.7M → 4700000
10u → 0.00001
Resistor notation:
1r5 → 1.5
4r7 → 4.7
10R → 10
The app automatically recognizes and converts these formats as you type. This is especially convenient when reading values directly from schematics or component labels.
Submitting Values
Values are submitted when you:
Tap outside the input field
Press Return/Enter
Navigate to another field
1.3. Understanding Inputs and Outputs
Automatic Input/Output Detection
Calculation tools intelligently determine which parameters are inputs and which are outputs based on what you’ve entered. This creates a natural, equation-solving experience:
Enter known values in any combination
The tool automatically identifies what can be calculated
Results appear as outputs below a dividing line
Parameters dynamically reorder as you work
Visual Distinction
Input and output parameters are visually distinct:
Input fields (white/dark background) – Editable values you provide
Output fields (blue-tinted background) – Calculated results
As you enter values, the tool reorganizes the display to show inputs above a horizontal line and calculated outputs below it. This reorganization happens smoothly with animation, making it clear what role each parameter plays.
Example: Voltage Divider
Voltage Divider tool showing the input and output fields
When you open the Voltage Divider tool:
Enter R1 = 10kΩ, R2 = 10kΩ, and Vin = 12V
These appear as inputs (above the line)
Vout is automatically calculated as 6V and appears as output (below the line)
Now tap Vout and change it to 3V:
Vout moves above the line (becomes an input)
The oldest input (e.g., R1) moves below the line (becomes an output)
R1 is recalculated to achieve your desired Vout
This intelligent behavior eliminates the need to manually specify “solve for” modes—just enter what you know, and the tool figures out the rest.
Required Inputs
Each tool requires a specific number of inputs to perform calculations. Make sure to enter all the required inputs.
1.4. Changing Unit Scales
Quick Unit Switching
Every parameter displays its unit (Ω, V, A, F, H, Hz, etc.) on the right side of the input field. When multiple units are available, tap the unit to open a menu:
Unit selection menu showing available scales
For example, resistance can be displayed in:
Ω (ohms) – Base unit
kΩ (kiloohms) – Thousands of ohms
MΩ (megaohms) – Millions of ohms
The value automatically converts when you change units, preserving the actual quantity while adjusting the display scale to your preference.
Persistent Unit Preferences
The app remembers your unit choice for each parameter. If you prefer working in microfarads (μF) for capacitors, the tool will continue using μF even after you close and reopen it.
1.5. E-Series Values Quick Access
For resistors, capacitors, and inductors, the app provides instant access to standard E-Series values—the preferred values used in electronic components.
Using E-Series Selection
When an applicable parameter is displayed, you’ll see an E-Series button (showing “E6”, “E12”, “E24”, etc.) next to the unit:
Tap the E-Series button to open the value picker
Choose a series (E6, E12, E24, E48, E96, E192) using the segmented control
Select a value from the scrollable list
The list automatically:
Highlights the value closest to your current input
Shows the percentage deviation from your current value (+2.1%, -1.5%, etc.)
Displays values in your selected unit (Ω, kΩ, MΩ, etc.)
E-Series value picker showing E24 values with percentage deviations
This feature is invaluable when designing circuits with real components—you can quickly find the nearest standard value without consulting tables or doing mental math.
E-Series Standards
E6 – 6 values per decade (~20% tolerance)
E12 – 12 values per decade (~10% tolerance)
E24 – 24 values per decade (~5% tolerance)
E48 – 48 values per decade (~2% tolerance)
E96 – 96 values per decade (~1% tolerance)
E192 – 192 values per decade (~0.5% tolerance)
1.6. Circuit Diagrams
Many calculation tools include interactive circuit diagrams that visualize the circuit being analyzed.
Dynamic Updates
Circuit diagrams automatically update to reflect your current parameter values:
Component values display on the diagram (resistors show their resistance, capacitors show their capacitance, etc.)
Input and output voltages update in real-time
Circuit configuration changes based on tool settings (e.g., NE555 in astable vs. monostable mode)
This immediate visual feedback helps you verify that the tool configuration matches your intended circuit.
Viewing Full Size
To examine a circuit diagram in detail:
Tap the circuit diagram
A full-screen preview opens
Pinch to zoom or use standard image viewing controls
Tap outside or use the close button to dismiss
This is especially useful on iPhone, where screen space is limited, and for complex circuits with many components.
Circuit diagram showing component values from current calculation
1.7. Formulas and Mathematical Expressions
Formula Display
When the tool calculates a result, the relevant mathematical formula appears in a dedicated section. Formulas are rendered in proper mathematical notation using LaTeX, making them clear and publication-ready.
Formula section showing the equations used in calculations
Multiple formulas may appear if the tool performs several related calculations.
Copying Formulas
You can tap any formula to copy it to the clipboard. This is useful when:
Creating documentation
Sharing calculations with colleagues
Referencing formulas in your own notes
After tapping, a brief “Copied” message confirms the action.
1.8. Secondary Results
Many tools calculate additional related values beyond the primary outputs. These appear in a “Secondary Results” section and might include:
Voltage Divider Example:
Total resistance
Current through the circuit
Power dissipated by each resistor
Resistance ratio
Voltage ratio
Attenuation in dB
Ohm’s Law Example:
Power dissipation
Energy over time
Conductance
These secondary calculations save you time and provide deeper insight into circuit behavior without requiring additional tools.
1.9. Tool Configuration
Some calculation tools offer configuration options to handle different circuit topologies or operating modes.
Example: NE555 Timer
The NE555 tool includes:
Mode selector – Switch between Astable and Monostable operation
With Diode toggle – Enable/disable diode for 50% duty cycle in astable mode
When you change these settings, the tool:
Updates the circuit diagram
Adjusts which parameters are relevant
Recalculates using the appropriate formulas
Configuration options are presented clearly at the top of the tool, typically using:
Segmented pickers for mode selection
Toggles for binary options
Dropdown menus for longer lists of options
1.10. Exporting to PDF
Every calculation tool supports PDF export, creating professional documentation of your calculations.
Creating a PDF
On both Mac and iOS/iPadOS:
Tap the Export PDF button in the toolbar (document icon)
The app generates a formatted PDF containing: - Tool title - All input parameters with their values and units - All output results with their values and units - Formulas used in calculations - Circuit diagrams (if applicable) - Secondary results
The PDF opens in Quick Look for viewing
Use the share button to save, email, or export the PDF
PDF export button in the toolbar
PDF Contents
The generated PDF includes:
Professional formatting with clear sections
High-resolution circuit diagrams embedded as images
Properly formatted formulas in mathematical notation
All parameter values clearly labeled with units
Timestamp showing when the calculation was performed
This makes PDF export ideal for:
Project documentation
Design reviews
Educational materials
Archiving calculations
Sharing with colleagues who don’t have the app
1.11. Tips for Efficient Use
Quick Navigation
Use the Search tab to jump directly to any calculation tool
Pin frequently used tools to the sidebar for instant access
On Mac, open multiple windows (⌘+N) to work with several tools simultaneously
Value Entry Shortcuts
Copy values from datasheets and paste directly—the app parses them automatically
Use resistor notation (4k7, 1M2) to match schematic conventions
Tap a unit to quickly change scale without re-entering the value
Workflow Integration
All tool states are automatically saved—close and reopen without losing work
Tool states sync via iCloud across your devices
Use PDF export to integrate calculations into your documentation workflow
Understanding Results
Check secondary results for additional insight into circuit behavior
Review formulas to understand the calculation methodology
Compare E-Series values to find practical component choices
1.12. Common Questions
What happens if I enter too many inputs?
The tool automatically demotes the oldest input to an output, recalculating its value based on your more recent entries. This ensures the tool always has the right number of inputs to solve the equations.
Why did my parameter move?
Parameters reorganize themselves to show inputs above the dividing line and outputs below. This dynamic layout makes it clear which values you’re providing and which are being calculated.
Can I lock an input so it doesn’t become an output?
Currently, the most recent inputs are prioritized. If you need specific parameters to remain as inputs, enter them last or avoid entering more inputs than the tool requires.
Do circuit diagrams show actual component values?
Yes—circuit diagrams update in real-time to display the current parameter values from your calculation. This provides immediate visual feedback.
Are formulas accurate?
All formulas are based on established electronic engineering principles and equations. For specialized applications or extreme conditions, consult detailed references or simulation tools.
2. Using the Resource Tools
Electronic-Toolbox 2 includes an extensive collection of reference materials and databases to support your electronics work. Resource tools provide quick access to component specifications, pinout diagrams, development board references, wire tables, and much more—all organized for efficient browsing and searching.
This chapter explains how to navigate and use the resource tools effectively.
2.1. Overview of Resource Tools
Resource tools are organized into several categories:
Semiconductors – Datasheets and specifications for transistors, diodes, MOSFETs, and other semiconductor components
Integrated Circuits – Reference information for common ICs including timers, op-amps, voltage regulators, and logic gates
Development Boards – Pinout diagrams, specifications, and programming references for Arduino, Raspberry Pi, ESP32, and other boards
Components – Tables and references for passive components, connectors, and standard parts
General Reference – Wire gauge tables (AWG, SWG), frequency allocations, and other reference data
Each resource tool presents its information in a format optimized for the type of data—whether that’s a searchable list, a sortable table, or a categorized collection.
2.2. Browsing Resource Entries
Most resource tools use a split-view layout that adapts to your device:
On Mac and iPad (Regular Size):
The interface shows a two-column layout:
Left column – Scrollable list of all entries
Right column – Detailed information for the selected entry
To browse:
Click any entry in the left list to view its details
Use arrow keys (↑/↓) to navigate between entries
Scroll the detail view independently to read full specifications
Resource tool showing split-view with list and detail panels
On iPhone (Compact Size):
The interface uses push navigation:
Tap an entry from the list to navigate to its detail view
Use the back button (←) to return to the list
The navigation flow is similar to browsing folders
Resource tool navigation on iPhone
2.3. Searching for Entries
Every resource tool includes a search function to help you quickly find what you need.
Using Search:
Look for the search field at the top of the screen on macOS and iPad, and at the bottom on iPhone
Start typing—results filter as you type
Search looks across all relevant fields (names, descriptions, specifications)
Clear the search field to see all entries again
Search Features:
Real-time filtering – Results update immediately as you type
Relevance sorting – Best matches appear first when searching
Multi-field search – Searches across names, part numbers, descriptions, and specifications
Smart matching – Finds partial matches and ignores capitalization
2.4. Using Filters
Many resource tools provide advanced filters to narrow down large lists by specific criteria.
Filter panel showing available filter options
Accessing Filters:
Tap the Filter button in the toolbar (funnel icon)
A filter panel appears showing available filter options
The button shows a badge indicating how many filters are active
Filter Types:
Value Filters (Chips)
Select from predefined options like categories or types:
Tap any chip to toggle that filter on/off
Multiple selections work as “OR” (show entries matching any selected value)
Active chips are highlighted with a checkmark
Toggle Filters
Simple on/off switches for specific criteria:
Toggle switches for yes/no filters
Example: “Only show recommended” or “Include discontinued”
Range Filters
Filter numeric values within a range:
Toggle Min and/or Max to activate bounds
Drag the range slider to adjust values
Current range displays above the slider
Useful for filtering by current capacity, voltage, frequency, etc.
Managing Filters:
Active filter count appears on the Filter button
Use Clear button to remove all active filters at once
Filters work together with search for maximum precision
Tap Done to close the filter panel (filters remain active)
2.5. Category Navigation
Some resource tools (like Raspberry Pi, Arduino) organize content into categories for easier browsing.
Main Categories View:
When you open these tools, you see a grid of category cards showing:
Category icon or representative image
Category name and description
Count of items in that category
Navigating Categories:
Tap any category card to view its contents
Each category opens to a filtered view of relevant entries
Use the back button to return to the main category overview
All search and filter features work within categories
Example: Raspberry Pi Tool
Boards – All Raspberry Pi board models with specifications
Pinouts – GPIO pinout diagrams for different models
Code Snippets – Common code examples for Raspberry Pi
Linux Commands – Reference for useful terminal commands
Information Gathering – Commands to check system info
Category cards in the Raspberry Pi resource tool
2.6. Working with Tables
Some resource tools (like wire gauge tables) present data in sortable tables rather than list views.
Table Features:
Sortable columns – Tap any column header to sort by that value
Multiple columns – View many specifications at once
Horizontal scrolling – Swipe left/right to see additional columns
Detail panel – Select a row to see expanded information
Sorting Data:
Tap a column header to sort ascending (smallest to largest)
Tap again to sort descending (largest to smallest)
Tap a third time to return to default order
The currently sorted column shows an indicator
Example: AWG Wire Table
The AWG (American Wire Gauge) table lets you:
Sort by gauge number, diameter, current capacity, resistance
Compare values across different units (mils/mm, circular mils/mm²)
Select a row to see detailed specifications and calculators
Filter by current range to find appropriate wire gauges
Sortable table showing wire specifications
2.7. Viewing Images and Diagrams
Resource tools often include images such as pinout diagrams, board layouts, and schematic references.
Image Viewing:
Images display inline within the detail view
Tap any image to view it full-screen
In full-screen mode: - Pinch to zoom for detailed examination - Drag to pan around zoomed images - Tap outside or use close button to return
Image Types:
Pinout diagrams – GPIO layouts, connector pin assignments
Board photos – Top and bottom views of development boards
Mechanical drawings – Dimensions and mounting hole locations
Schematics – Circuit diagrams and block diagrams
This is especially valuable when you need to reference pinouts while wiring, as you can zoom in to read individual pin labels clearly.
2.8. Opening Documents and Files
Many resources link to PDF manuals, datasheets, and other documents.
Document Types:
Datasheets – Component specifications and characteristics
User manuals – Setup guides and instructions
Application notes – Design guidelines and examples
Reference documents – Standards and technical specifications
Accessing Documents:
Resources display documents in one of two ways:
Bundled Documents (Included with App):
Button shows “Open” label
Tap to open immediately in Quick Look
No download required—works offline
Downloadable Documents (On-Demand):
Button shows “Download” label with download icon
Tap to download (progress indicator appears)
Once downloaded, button changes to “Open”
Downloaded files are cached for offline access
Document download button
Viewing Documents:
Once opened in Quick Look, you can:
Scroll through multi-page PDFs
Zoom in to read fine print
Use the share button to export, print, or save elsewhere
Documents remain open until you close them
Batch Document Loading:
Some entries have multiple related documents:
A “Load All” button downloads all documents at once
Status shows count of loaded/failed documents
Expand/collapse the list to see individual documents
Failed downloads can be retried individually
2.9. Opening External Links
Resource tools may include links to external websites for manufacturers, documentation, or additional resources.
Link Presentation:
Links appear with:
Link icon (🔗)
Link title or website name
“Open” button
Opening Links:
On iOS/iPadOS:
Tap the “Open” button
Link opens in an in-app web view
Browse the website within the app
Close the web view to return to the resource tool
On Mac:
Click the “Open” button
Link opens in your default web browser
The app remains open in the background
This allows you to access manufacturer websites, online calculators, and additional documentation without leaving your workflow.
2.10. Working with Specifications
Detail views present specifications in organized, easy-to-read formats.
Specification Layouts:
Tables:
Structured data with headers and multiple columns, ideal for comparing values across different conditions or configurations.
Collapsible Sections:
Complex specifications organized under expandable headers to reduce clutter while keeping all information accessible.
Text Selection:
All specification text is selectable
Long-press or click-and-drag to select
Copy values to use in calculations or documentation
Particularly useful for part numbers and command syntax
2.11. Tips for Efficient Use
Quick Navigation:
Use search as your primary navigation tool—it’s faster than scrolling
Pin frequently referenced resource tools to the sidebar
Use keyboard navigation (↑/↓ arrows) on Mac/iPad to browse quickly
Working with Multiple References:
On Mac, open multiple windows (⌘+N) to reference several tools simultaneously
Compare specifications side-by-side
Keep a pinout diagram open while using calculation tools
Offline Access:
Most resource data is included with the app and works offline
Download frequently referenced documents for offline availability
Downloaded documents are cached automatically
Search Strategies:
Start with specific terms (part numbers, model names)
Use partial matches if you’re unsure of exact spelling
Try different terms if first search doesn’t yield results
Combine search + filters for precise results in large databases
Using with Calculations:
Keep resource tools open while using calculation tools
Reference pinouts while designing circuits
Check component specifications before entering values
Verify wire gauges for current capacity calculations
2.12. Common Questions
Why do some documents need to be downloaded?
Large documents are stored online to keep the app size manageable. They download quickly when needed and are cached for offline use afterward.
Can I export or share specifications?
Yes—select and copy any text from detail views. For complete datasheets, use the share button in Quick Look after opening a document.
How do I find a specific pin on a large pinout diagram?
Open the diagram full-screen, then pinch to zoom in. The high-resolution images remain sharp when zoomed, making individual pin labels easy to read.
Do filters persist when I close the app?
Filters are session-based and reset when you close the tool. This ensures you always start with a complete view. Use search for quick filtering that’s easy to clear.
Can I suggest additions to the resource databases?
Yes—use the “Contact Developer” feature in Settings to suggest components, boards, or other resources you’d like to see added.
3. Using the Oscilloscope and Frequency Counter
Electronic-Toolbox 2 includes two powerful audio analysis tools: an Oscilloscope for visualizing waveforms and a Frequency Counter for precise frequency measurement. Both tools use your device’s microphone or audio input to analyze electronic signals in real-time.
These tools are found under the Tools tab in the main navigation.
3.1. Oscilloscope
The Oscilloscope tool provides real-time visualization of audio signals with professional-grade features adapted for mobile and desktop use.
Oscilloscope displaying a captured rolling waveform
Getting Started
Open the Oscilloscope from the Tools tab
The tool automatically starts capturing from your device’s microphone
Connect your signal to the audio input (use appropriate adapters if needed)
Adjust settings to optimize the display
Main Display Modes
The oscilloscope offers two visualization modes:
Waveform View – Shows signal amplitude over time, like a traditional oscilloscope screen
Spectrum View – Shows frequency spectrum analysis (FFT) with magnitude per frequency
Switch between modes using the mode selector at the top of the display.
Key Controls
Time Base
Adjusts the horizontal time scale:
Range from 1ms to 100ms per division
Controls how much time is displayed across the screen
Slower speeds show more cycles, faster speeds show fine detail
Amplitude Scale
Adjusts the vertical voltage scale:
Available scales: 1×, 2×, 5×, 10×
Controls the zoom level for signal amplitude
Adjust to fit your signal within the display area
Amplitude Offset
Shifts the waveform vertically:
Use the slider to center the signal
Helpful when analyzing signals with DC offsets
Does not affect measurements, only display position
Trigger Settings
The trigger stabilizes the display to show repeating waveforms clearly:
Trigger Mode – Auto (continuous), Normal (waits for trigger), or Single (one-shot capture)
Trigger Level – Amplitude threshold that starts the display sweep
Trigger Edge – Rising or falling edge detection
Holdoff – Delay between trigger events
Proper trigger settings are essential for viewing stable periodic signals.
Measurements Panel
The oscilloscope automatically measures and displays:
Frequency – Signal frequency in Hz, kHz, or MHz
Period – Time for one complete cycle
Peak-to-Peak Voltage – Total amplitude from minimum to maximum
RMS Voltage – Root-mean-square voltage (effective voltage)
Duty Cycle – Percentage of time the signal is high (for square waves)
These measurements update in real-time as the signal changes.
Tips for Best Results
Start with Auto trigger mode to see your signal
Adjust time base so 2-3 complete cycles are visible
Use amplitude scale to fill 50-80% of the display vertically
Switch to Normal trigger for unstable or noisy signals
Use Spectrum view to analyze harmonic content
3.2. Frequency Counter
The Frequency Counter provides accurate frequency measurement with high precision, ideal for testing oscillators, tuning signals, and verifying frequency sources.
Getting Started
Open the Frequency Counter from the Tools tab
The tool automatically starts measuring from your device’s microphone
Connect your signal to the audio input
The frequency reading appears in large digits
Measurement Display
The main display shows:
Current Frequency – Large numerical display with automatic unit scaling (Hz, kHz, MHz)
Period – Time for one complete cycle (ms, μs)
Confidence Indicator – Visual indicator of measurement stability
Method – Shows whether measurement uses time-domain or spectrum analysis
Measurement Settings
Method
Choose how the counter measures frequency:
Auto – Automatically selects best method based on signal characteristics
Time-domain – Counts zero-crossings, best for low frequencies and square waves
Spectrum – Uses FFT analysis, best for high frequencies and complex waveforms
Most users should leave this on Auto for optimal results.
Gate Time
Controls the measurement integration period:
Longer gate times (1-2 seconds) provide higher precision but slower updates
Shorter gate times (0.1-0.5 seconds) update faster but with less precision
Adjust based on your signal stability and required accuracy
Additional Settings
Hysteresis – Noise threshold for zero-crossing detection
Smoothing – Averaging filter to reduce reading fluctuations
Hold – Freezes the display to capture a specific reading
Decimals – Number of decimal places displayed
Frequency Trace
The frequency trace shows measurement history over time:
Scrolling graph of recent frequency measurements
Helps visualize frequency drift and stability
Useful for tuning variable oscillators
Reading Accuracy
Accuracy depends on several factors:
Signal strength – Stronger signals provide more accurate readings
Signal purity – Clean sine waves measure better than noisy signals
Gate time – Longer gate times improve resolution
Frequency range – Optimal range is 20 Hz to 20 kHz (audio spectrum)
For best accuracy, use a clean signal at moderate amplitude.
Practical Applications
Testing oscillator circuits
Calibrating frequency generators
Verifying crystal frequencies
Measuring PWM signal frequencies
Analyzing audio tones
Checking function generator output
3.3. Using Audio Inputs
Both tools use your device’s audio input. Consider these connection methods:
iPhone/iPad
Use a Lightning to 3.5mm audio adapter (if needed)
Connect signals through a protective interface circuit
Never connect voltages exceeding microphone input limits (typically < 1V)
Mac
Use the built-in microphone for acoustic signals
Connect line-level signals through the audio input jack or USB audio interface
Ensure signal levels match input specifications
Safety Warning
⚠️ Never connect high-voltage signals directly to audio inputs. Use appropriate signal conditioning, isolation, or attenuators to protect your device. Audio inputs are designed for low-voltage signals only.
For measuring circuits at higher voltages, use an external oscilloscope or frequency counter with proper voltage range.
3.4. Tips for Best Results
Signal Connection
Use shielded audio cables to minimize noise pickup
Keep cable lengths short to reduce interference
Ground your test circuit appropriately
Use a USB audio interface for better signal quality on Mac
Environment
Work in a quiet environment when using microphone input
Minimize electromagnetic interference sources nearby
Place device on a stable surface to avoid mechanical vibrations
Measurement Technique
Allow measurements to stabilize for 2-3 seconds
Use Hold feature to capture transient readings
Compare readings across both tools to verify results
Export screenshots to document measurements
3.5. Common Questions
What frequency range can these tools measure?
Both tools are limited by audio input capabilities, typically 20 Hz to 20 kHz. Some USB audio interfaces extend the upper limit to 40-50 kHz.
Why does the frequency counter show fluctuating readings?
This usually indicates signal instability, noise, or inadequate signal strength. Try increasing gate time, enabling smoothing, or improving signal quality.
Can I use these tools with AC line voltage signals?
No. These tools require low-voltage audio signals only. Use proper signal conditioning and isolation for AC measurements.
How accurate are the measurements?
Accuracy is typically within 0.1% for clean signals with appropriate gate time settings. This is sufficient for most hobby and development work.
Can I record waveforms?
You can take screenshots of the display. For data logging, consider using dedicated data acquisition equipment.
4. Using the Tone Generators
Electronic-Toolbox 2 includes three tone generation tools for producing audio signals through your device’s speakers or audio output. These tools are useful for testing audio circuits, generating test tones, and producing standard telecommunications signals.
The tone generators are found under the Tools tab in the main navigation.
4.1. Frequency Generator
The Frequency Generator produces single or multiple audio tones simultaneously with precise frequency control.
Frequency Generator with waveform visualization
Getting Started
Open the Frequency Generator from the Tools tab
Set your desired frequency using the frequency input field
Choose waveform type and amplitude
Tap Start to begin playback
Waveform Types
Select from four standard waveforms:
Sine – Pure tone with single frequency, smooth waveform
Square – Sharp transitions, contains odd harmonics
Sawtooth – Linear ramp, contains all harmonics
Triangle – Linear ramp up and down, contains odd harmonics
Each waveform has distinct harmonic content suitable for different testing purposes.
Frequency Control
Direct Input
Enter frequency values directly:
Type any value with SI prefixes (e.g., 1k for 1000 Hz)
Supports standard and engineering notation
Range: 20 Hz to 20,000 Hz (audio spectrum)
Musical Notes
Select from standard musical notes:
Chromatic scale from C0 to C8
Each note shows its frequency value
Useful for audio testing and musical applications
Frequency Presets
Quick access to common test frequencies:
440 Hz (A4 – musical reference pitch)
1000 Hz (standard calibration tone)
Standard dial tones and signaling frequencies
Custom presets (save frequently used frequencies)
Multi-Tone Generation
Generate up to 3 simultaneous tones:
Tap Add Tone to create additional channels
Set frequency and amplitude for each tone independently
Each tone can use a different waveform
Useful for testing audio systems, creating harmonics, or generating complex signals
Amplitude Control
Adjust output level for each tone:
Individual amplitude sliders (0-100%)
Master volume control in toolbar
Visual waveform display updates in real-time
Waveform Display
The visualization shows the combined output waveform:
Real-time rendering of the generated signal
Shows effect of multiple tones combining
Helps verify the output before playback
Phase Control
When generating multiple tones:
Phase relationship between tones can be adjusted
Affects how waveforms combine
Useful for interference and beating demonstrations
Practical Applications
Testing audio amplifiers and speakers
Calibrating audio equipment
Generating reference tones for tuning
Testing frequency response
Creating audio test signals
Educational demonstrations of waveforms
4.2. DTMF Generator
The DTMF (Dual-Tone Multi-Frequency) Generator produces telephone keypad tones used in telecommunication systems.
DTMF Generator with telephone keypad interface
Getting Started
Open the DTMF Generator from the Tools tab
The standard telephone keypad appears
Tap buttons to generate corresponding tones
Release to stop the tone
Keypad Interface
The interface mimics a standard telephone keypad:
Number keys (0-9) – Standard telephone digits
Star (*) and Hash (#) keys – Special function keys
Each key generates two simultaneous tones (hence “dual-tone”)
How DTMF Works
Each key produces a unique combination of two frequencies:
Low-frequency tone (697-941 Hz) – Determines the row
High-frequency tone (1209-1477 Hz) – Determines the column
The combination uniquely identifies each key
This is the same system used by telephone networks for keypad input.
Sequence Playback
Generate sequences of DTMF tones automatically:
Enter a sequence of digits in the text field (e.g., “12345” or “555-1212”)
Set Tone Duration (time each tone plays)
Set Gap Duration (silence between tones)
Tap Play Sequence to start automatic playback
Tone Duration Settings
Adjust timing to match different systems:
Tone Duration – How long each tone plays (50-500ms)
Gap Duration – Pause between tones (50-500ms)
Standard: 100ms tone, 100ms gap
Fast dialing: 70ms tone, 70ms gap
Practical Applications
Testing phone systems and PBX equipment
Debugging telecommunications circuits
Demonstrating telephone signaling
Testing DTMF decoders
Ham radio DTMF operations
Educational demonstrations
Settings
Access settings via the toolbar button:
Adjust default tone and gap durations
Set output volume
Configure audio output routing
4.3. Tone Standards
The Tone Standards tool generates tones based on international telecommunications and signaling standards.
Tone Standards with standard selection interface
Getting Started
Open the Tone Standards from the Tools tab
Choose a Tone Standard from the list
Select a specific Code or Tone from that standard
Tap the tone to play it
Available Standards
The tool generates tones based on two-tone selective calling and squelch systems commonly used in radio communications.
DTMF (Dual-tone multi-frequency)
Used in telephone systems for keypad input. Generates pairs of tones corresponding to digits and symbols.
Selective Calling (SelCall) Systems
These European standards transmit a burst of five in-band audio tones to initiate conversations. In simplex systems, they open the speaker of the desired partner. Available standards include:
SelCall CCIR
SelCall EEA
SelCall EIA
SelCall ZVEI I
SelCall ZVEI II
SelCall ZVEI III
SelCall DZVEI
SelCall PZVEI
CTCSS / Tone Squelch
CTCSS (Continuous Tone-Coded Squelch System) superimposes one of about 50 continuous audio tones (67-254 Hz) on the transmitted signal. Often called PL tone or simply tone squelch.
Tone Burst
An obsolete method of selective calling where the radio transmits a single 0.5- to 1.5-second audio tone at the beginning of each transmission.
Standard Selection
Browse by standard type:
Choose a tone standard category
View available codes or tones in that standard
See frequency specifications for each tone
Tap to generate the tone
Tone Information Display
For each tone, the tool shows:
Tone name – Description of the signal
Frequencies – Exact frequency values used
Duration – Standard tone duration (if applicable)
Purpose – What the tone signals in practice
Standard reference – Official specification code
Waveform Visualization
The display shows the generated tone’s waveform:
Real-time rendering of the dual or single-tone signal
Helps understand the tone’s composition
Updates when switching between different tones
Sequence Generation
Some standards support sequence playback:
Enter a sequence of codes
Set timing parameters
Play the complete sequence automatically
Practical Applications
Testing radio equipment and decoders
Verifying selective calling implementations
Learning about radio signaling standards
Debugging communication systems
Ham radio experimentation
Educational demonstrations of telecom systems
Volume Control
Master volume control in toolbar:
Adjust output level for all generated tones
Prevents excessively loud playback
Independent of device volume
4.4. Audio Output Configuration
All tone generators support various audio output options:
Built-in Speakers
Default output on all devices
Convenient for testing and demonstrations
Limited power and frequency response
Headphones/External Speakers
Connect via headphone jack or Bluetooth
Better quality for audio testing
Prevents acoustic feedback in some test scenarios
Audio Interfaces
Use USB audio interfaces for professional applications
Better signal quality and higher output level
Multiple output channels available on some interfaces
Output Level Considerations
Start with low volume when connecting to audio circuits
Increase gradually to avoid overdriving inputs
Never connect tone generator output directly to high-impedance inputs without appropriate matching
4.5. Safety and Best Practices
Volume Safety
Start playback at low volume
Gradually increase to desired level
Avoid prolonged exposure to loud tones
Use headphones carefully—limit maximum volume
Circuit Testing
Verify input requirements before connecting signals
Use appropriate attenuators or matching circuits
Don’t exceed the maximum input level of test equipment
Use shielded cables to minimize interference
Acoustic Considerations
Long tones can be annoying—keep durations reasonable
Use headphones when testing in shared spaces
Some frequencies may trigger acoustic resonances in rooms
Pet and child safety—some high frequencies may be unpleasant
4.6. Tips for Effective Use
Testing Audio Circuits
Start with sine waves at 1 kHz for basic testing
Use square waves to test frequency response
Generate harmonics with square/sawtooth for distortion testing
Compare input and output with Oscilloscope tool
Calibration Work
Use 440 Hz or 1000 Hz for standard reference
Generate multiple tones to test channel separation
Use DTMF tones to test decoder circuits
Verify tone standards implementation with Tone Standards tool
Workflow Integration
Use Oscilloscope to visualize generated tones
Use Frequency Counter to verify output accuracy
Take screenshots to document test setups
Combine with Calculation Tools for circuit design
Saving Settings
All tools remember their last settings
Frequency presets are saved automatically
Volume levels persist between sessions
Tool states sync via iCloud across devices
4.7. Common Questions
What’s the maximum output frequency?
All tone generators are limited to the audio spectrum (20 Hz - 20 kHz) by design and by device audio hardware.
Can I generate tones above 20 kHz for ultrasonic testing?
No. Device audio hardware and the app are limited to human-audible frequencies.
Why does the frequency sound wrong?
Verify your device volume isn’t too low or high. Extremely loud volumes can cause distortion. Also check that Bluetooth audio delay isn’t affecting perception.
Can I use these generators for musical applications?
Yes, especially the Frequency Generator with musical note presets. However, dedicated music apps provide more features for musical composition.
How accurate are the generated frequencies?
Frequency accuracy is determined by your device’s audio hardware sample rate, typically ±0.01% or better. This is sufficient for most testing and calibration work.
Can I save custom frequency presets?
The Frequency Generator remembers your last-used frequencies and settings. For repeated use, tools automatically restore previous states.