Zelscope Sound card oscilloscope

Zelscope is a Windows software that converts your PC into a dual-trace storage oscilloscope and spectrum analyzer. It uses your computer’s sound card as analog-to-digital converter, presenting a real-time waveform or spectrum of the signal – which can be music, speech, or output from an electronic circuit.

Zelscope Sound card oscilloscope

Zelscope features the interface of a traditional oscilloscope, with conventional gain, offset, timebase, and trigger controls. As a real-time spectrum analyzer, Zelscope can display the amplitude and phase components of the spectrum.

Zelscope Sound card oscilloscope

The typical input voltage should be about 1 volt AC at the line-in jack of the sound card, so a voltage divider or a buffer amplifier is highly recommended.

xoscope for Linux –  Similar Ptoject

Zelscope also allows for an easy measurement of short time intervals in mechanics experiments. Zelscope has proven useful in debugging music and sound processing software.

CircuitLab – Online Schematic Editor and Simulator

Draw and print beautiful schematics for lab reports. In-browser simulations make it easy to quickly learn electronics concepts. No need to Install, it is a Online Web Application !

CircuitLab – Online Schematic Editor & Simulator

Test and Simulate circuit ideas before breadboarding. SPICE-like models with a mixed-mode simulation engine help you apply one tool to a wide range of design tasks, from digital to analog, DC to VHF and beyond.

BJT Cascoded Active-load Differential Amplifier with CMFB

BJT Cascoded Active-load Differential Amplifier with CMFB

Build non-op-amp Common-Mode Feedback (CMFB) – This kind of high-gain differential input stage might be useful as part of an op-amp, but it’s a bit silly to include an op-amp within a stage another op-amp……

Some Examples

  • 555 Timer as Oscillator / PWM Generator
  • 7805 & Wall-wart Experiencing Voltage Drop-out
  • Digital 4-bit counter and DAC
  • Diode full-wave (bridge) rectifier
  • Laplace transform step response and Bode plot
  • LED with resistor biasing
  • MOSFET switching inductive load
  • Op-Amp inverting / non-inverting amplifier
  • RLC resonance
  • Zener diode voltage reference

BlackBoard – Circuit Layout.and Simulation

An Open Source “Learning EDA” Software which can setup circuit layouts. You may use it for stripboards, perfboards, breadboards, and even for plain circuitry or simulation. Creation and editing of symbols and elements on-the-fly using an integrated editor

BlackBoard – Circuit Layout.and Simulation

BlackBoard - Circuit Layout.and Simulation

The Library has more than 300 different elements and symbols. Has an Integrated SPICE simulation support with netlist generator. NGSPICE Frontend (comes along with NGSPICE for Windows).

BlackBoard Components

These are some of the Components in the Library. Makes Setting up a circuit layout fun.

Embedded Systems Made Easy – StickOS

“StickOS BASIC is intended to make embedded systems technology and advanced microcontroller functionality quickly and easily accessible to High School students, hobbyists, and researchers, etc., with minimal investment of time, education, and money.

Interfacing with digital circuitry, analog circuitry, serial circuitry (UART and SPI), servo motors, and buzzers, etc., all become trivial single-line, single-minute tasks in StickOS BASIC, so the user can concentrate on achieving the control task at hand, rather than the detailed mechanics of control.”

Embedded Systems Made Easy – StickOS

– Rich Testardi (mail) 2009

“StickOS BASIC is an entirely MCU-resident interactive programming environment, which includes an easy-to-use editor, transparent line-by-line compiler, interactive debugger, performance profiler, and flash filesystem, all controlled thru an interactive command-line user interface….

CPUStick is a 1″x4″ very low cost standalone USB embedded computer based on the Freescale MCF52252 ColdFire MCU and MC13201 ZigFlea Wireless Transceiver,…”

StickOS Examples – A simple embedded system, like a toaster oven temperature profile controller, can be brought online in record time!

LCD Digital Thermometer

LCD Digital Thermometer – With the advent of advanced serial peripherals based on the I2C or QSPI serial interfaces, embedded systems can take on a whole new level of real-world functionality! An LCD digital thermometer, displaying both Celsius and Fahrenheit, can be brought online in minutes, with just a quick study of the I2C peripheral register or protocol definitions!

Virtual Breadboard – Hardware Prototyping

VirtualBreadboard(VBB) is for designing and testing embedded software in high-level interactive circuit simulations and rapidly prototyping hardware from those designs.

Virtual Breadboard – Test Embedded Systems

Compared to other simulators many people find the high level approach taken VBB easier to use and much faster to model and test out new ideas and circuit variations.

From Design Gopher – Electronic Product Development

VBB electronic circuit components are modeled at the function block level and are wired together to create a real-time interactive circuit simulation representing the whole embedded application.

VBB does not use SPICE. SPICE is better suited to subcircuit designs whereas VBB is concerned with merging multiple subcircuits treating each subcircuit as a self contained function block.

OpCUBE Project – Object programmable CUBE

OpCUBE Project – Object programmable CUBE

Atmel’s AVR is most interesting chip, with modern 8-bit RISC MCU and rich I/O performance in less $ price. With tons of document available on web since simple D.I.Y. hardware project to complex system design.

AVR becomes the value choice for implement “Physical Computing” idea. The proposal of “physical Computing ” is made for interaction of hardware control “the real world” with easy software programming.

OpCUBE Project

MIDE-51 software package on web with ASEM-51 Assemmbler tools for MCS-51 beginner.

MCS-51 is the good MCU for getting start to learn and use. But now.. we have many microcontroller available on market. Modern chips had much more advantage features than old MCS-51 , e.g. Microchip’s PIC / dsPIC, Atmel AVR / AVR32 thru high-end ARM base MCU”

FreePCB – PCB editor

FreePCB – PCB editor

FreePCB is a free, open-source PCB editor for Microsoft Windows, released under the GNU General Public License. It was designed to be easy to learn and easy to use, yet capable of professional-quality work. It does not have a built-in autorouter, but it can use the FreeRoute web-based autorouter at freerouting.net. Some of its features are:


  • 1 to 8 copper layers
  • Board size up to 60 inches by 60 inches
  • Uses English or metric units (i.e. mils or mm) for most functions.
  • Footprint libraries courtesy of Ivex Design International Inc.
  • Copper fill areas
  • Footprint Wizard and Footprint Editor for creating or modifying footprints
  • Imports and exports PADS-PCB netlists
  • Exports extended Gerber files (RS274X) and Excellon drill files
  • Design rule checker
  • Autosave

Example – Logic Analyzer: This is an open-source logic analyzer called MiniLA contributed by Bob Grieb of the User Forum. The image on right is the Logic Analyzer PCB.

miniLA - mini Logic Analyzer

Some Features:

  • Up to 32 channels
  • 128 Kb of memory for each channel
  • Sampling rate up to 100 MHz (timebase in 1-2-5 sequence)
  • Input levels compatible with 3.3V and 5V logic
  • Selectable pretrigger/posttrigger buffer size in 8K step