An Introduction to Electronics Drafting Using CAD Software
Short tutorial on how to install EDA or eCAD software — Fritzing:
Objective
This lab is two pronged: first, practice designing on eCAD software "Fritzing" circuit problem sets, and, second, test these designs on physical bread boards.
Description
21st century have begun to oversee devices such as Glucose meters, Smart Phones and Tablets, Implanted Artifical Pacemakers, Digital Film Video and Film Production, and much more. Often the price of advanced electrical equipment are high. Though the materials used to manufacture them are cheap, yet the labour hours required to design, test and industrially mass produce is immense.
Nevertheless, prices of digital equipment decreases overtime. This is a direct result of global competition between companies to produce same products, which leads to effcient ways to design, fabricate, manufacture, and most importantly test fundamental building blocks of modern electronic equipment:
- PCBs - Printed Circuit Boards
- ICs - Integrated Circuits
Intel made it's mark from offering faster computer chips with upgrades from Pentium 1 to 2, 3, 4, Dual Core, Quad Core, i7, firstly, through better circuit topology and VLSI drafting, and, secondly, accurate micro-, nano- scale fabrication technologies. Skills and expertise in eCAD drafting allows you to realize your ideas for new hardware into reality. Plus, it is the one of the two bottle necks that can accelerate or slow more compact and powerful circuits. Aside Intel, other popular Electronics and Hardware producers investing in eCAD or EDA are AMD, Samsung, LG, Sony, Apple and much more. Figure 1 and 2 shows you electronic circuits before and after the advent of eCAD; do you notice the differences in hardware arangement with and without EDA?

Figure 1 A board inside an electronic eqiupment of the 1960. Hand drawn schemtics for very large circuits were useful form of communication to the manufacturer, but it prevented simulation and pre-manufacturing prototyping, resulting in bulky and not compact boards.

Figure 2 Modern board manufactured after full schematic was designed and optimized via EDA. Resulting boards are compact, tidy and have easier maintenance due to modular placement of working circuit blocks.

Figure 3 Magified view of paths between circuit elements and operational blocks in a Printed Circuit Board (PCB) circuit, which before the advent of EDA were physical wires as seen in Figure 1.
Software Tools
EDA tools are similar to productivity software. They are sold by software engineering companies, who are either for-profit and closed-source, or for-profit and open-source, or not-for-profit. Both open-source and closed-source CAD tools are used in industry, the former is more popular in academia and research, the later in private electrical producers. Two industry standards currently are:
Exercise — Drafting a Light Switcher
In this exercise you prototype your first light or LED switcher. This is your first design with eCAD software "Fritzing". Therefore, the circuit you will design is most basic to keep you in ease.
Materials
The LED switcher consists of:
Element | Quantity |
---|---|
3 Volt DC Source | 1 |
Figure 4 through 14 visually guides you to make your circuit schematic, real-world view or breadboard view, pcb view.

Figure 4 These are components and circuit elements whose value, size, and behaviour can be adjusted from the inspector panel.

Figure 5 The drawing space shows you the view you chose from parts panel. This is your board or paper where you place items or draw designs.

Figure 6 These tools allow you to rotate the part you dragged placed in circuit arrangement on drawing space, join all unjoined circuit elements in optimized paths, zooming in on paths, and more.

Figure 7 These options tabs are administrative in nature, thus use them to customize your Fritzing.

Figure 8 Place each element on shematic. To "wire" each circuit element with the other, just drag the terminal of one element to the next.

Figure 9 You should use note from tools panel to remind others or yourself or yourself of a process.

Figure 10 Correct the resistor value to the nearest resistor available in the parts kit or parts panel through the inspector drop down menu.

Figure 11 Select the LED from the parts panel. You can change the property of this LED from the Inspector panel below the parts panel

Figure 12 Drag one of the unconnected terminals of LED to the Resistor. Move the label for the component to have a clear view.

Figure 13 A schematic can have many ways it can be connected. Here, it has been purposely drawn with bent connections. Do SHIFT+ dragging of the unconnected terminals of the circuit.

Figure 14 Click the connection and drag up, down, left or right to make the connection straight. Press SHIFT while you drag to get straight connections.

Figure 15 If you see two or more nodes making a connection between two terminals, delete the whole path, and re-connect the terminals with only one node. Let the line be bent. Then, while pressing SHIFT drag them &emdash; for sure you will achieve straight connections.

Figure 16 After correcting, this schematic is professional - but, not complete yet. Imaging you were a distant manufacturer producing electrical equipment, say Christmas Lights. You would need detailed description of each circuit element: useful for large scale PCBs.

Figure 17 Double click on the electronic element. Dialog box appears; put the custom title for it.

Figure 18 After repeated labelling (with turning of a label or more through left clicking, and straightening connection orientations), you will have a professionally designed circuit prototype.

Figure 19 After schematic is complete, switch to breadboard view. Notice that nothing is properly connected! Drag each element into the power rows. Drag one unconnected terminal to the other ‐ remember to press SHIFT to straighten nodes or wires. The blue connections representing wires.

Figure 20 This is one of many arrangements of the circuit elements, correctly on a bread board.
This visualization allows you to design efficient designs when the proejct is large scale. Your first drawing of the LED switcher is very small scale, hence it may seem with this exercise designing in advance is optionsl. However, with all real life electrical design engineering, without proper drafting, you have 100 percent guarantee of making faulty circuit giving you wrong, or at worst, no result at all.
Say, this circuit was being used as a buzzer notifier in a game show, like Jeopardy, it would be manufactured to go along with other circuitry at the podium: buzzer alarm, points displayer, etc. The LED switcher would be converted to a PCB design, before it is professionally manufactured. Figure below shows you how you accomplish this in Fritzing.

Figure 21 Change to PCB view. Similar to first breadboard life-like view, nothing is neither placed nor wired properly.

Figure 22 Click and move the elements. Delete any wirings that may prevent you from placing elements in a logical arangement. You have many possible arrangements, what is shown is just one out of, perhaps, nine other ways.

Figure 23 After connecting the terminals, you will have a PCB design ready to be exported as a PCB formatted file: use the export to PCB tool in the tools panel.
Keep in mind while you engineer your electrical technologies:
- Mistake free designs happen because of good drawing practices during schematic process.
- Professionals always prototype, visualize the circuit on breadboard and/or PCB, then simulate it. Try simulating this LED switcher at this open-source, free, simulator.
- Famous design engineers always keep notes on computer or hand-written notebooks of their work.
Happy designing!
Further Readings
To have a deepened knowledge in Automated Electronic Drafting, you should first gain a "knowledge scaffold and learning directions" of powerful math, science, computer technologies and engineering. Learn more as a student or teacher from free schools:
Once you are feel confident, please Search with keywords "Prototyping Electronic Circuits", "Printed Circuit Board Fundamentals", "Integrated Circuit VLSI", "Circuit Topology", "History of Electronics"at UOIT Library or Open Textbooks and Open Encyclopediae:
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