Concept Development

Early in the early days of electronics, and by electronics I mean active components (the ones needing to be powered) starting with tubes, circuits were made by connecting everything with wires. These were not traces on a printed circuit board (PCB). These were actual wires that were soldered to the terminals of devices, active and passive components alike. PCBs came much later.

As such, and by today’s state of affairs, it was easy to wire together an electronic circuit. Nearly anyone could do it. Circuits were simpler in the beginning. The first radios, after all, needed only one tube. The main skill needed was soldering.

An advantage to this simple assembly methodology is that amateurs, professionals, and students of electronics could easily experiment. One really only needed soldering tools and the electrical components themselves. Hobbyist magazines flourished in the early days as the allure of this new, attainable technology fascinated those curious individuals among us.

After World War II, another phenomenon surfaced - the availability of electronics kits. Many companies sold the components and provided booklets of instructions on how to assemble the components to make a finished product. Those booklets included a “theory of operation” that explained how the assembled components worked and the functions they served. Heathkit, Eico, Precision, and others were companies making such kits. One could build their own radio, oscilloscope, television, and numerous other products. It was a great time to be interested and to learn about electronics.

From tubes, we transitioned to transistors, but the wiring was still simple. Circuits consumed less space when using transistors and they could be built with terminal strips consisting of rows of solder terminals attached to a non-conductive strip such as phenolic. Circuits were becoming more complex in this age due to the decreasing expense of electronic devices and more sophisticated functionality could be implemented. But as this complexity grew, it became increasingly necessary to simplify wiring and the PCB came into existence.

PCBs were nice because practitioners didn’t need any new tools and already had the requisite know-how - soldering. Perhaps one needed only a smaller tip for his or her soldering iron. A popular method to make these early PCBs was to lay opaque tape on a piece of mylar wherever conductive material was desired. Through photograph processes, one could “etch” the pattern of tape onto a copper clad board. The process required to make a PCB eliminated players from the field. Fewer people were willing or had the know-how, to make their own PCB. Alternatively, one could pay to have a PCB made for them, but this added expense surely motivated people to “drop out” of the field.

However, there were so many exciting new products being visibly produced that it remained an enticing field to many. Electronics have become so advanced that the range of what can be implemented from one’s imagination is practically unlimited. This is excellent for the discipline whether practiced by electrical engineers, physicists, students, hobbyists, or anyone with enough interest and persistence.

From the early days of PCBs to now, where PCBs have become the ubiquitous means of “wiring” components together, electronics themselves were undergoing a revolution. We transitioned from discrete transistors to integrated circuits (ICs). ICs are the essence of pre-assembled PCBs containing electronics. Because they significantly reduced the size of complex electronic circuits, and because an IC’s cost is directly proportional to its size as measured by the area consumed on a silicon substrate, they too were driven to be smaller and it then became impractical to use anything but PCBs to wire electronic circuits together. There are exceptions to this but I claim this is generally true.

During this early time of ICs, one could develop a concept and debug its electronics with typical laboratory instruments like multimeters and oscilloscopes. One could access device pins and probe junctions of circuits with relative ease but smaller electronic products were more desired by customers than larger ones. People wanted portability. They also wanted increased functionality and lower costs.

Increased functionality and lower cost while also keeping the size small is probably the most popular reason to develop an electronic product or to redesign an existing one and there has been one way to do this - through higher levels of integration coming in the form of more capable ICs. The lifeblood of this industry is advancing semiconductor technology. We see this in the form of our smartphones where today’s model has more functionality at a lower cost than previous models. Now, you may object to my claim of lower cost and I would ask if you are referring to a product’s price or its cost. I assure you that the cost for a given level of functionality is lower and, other things being equal, its price is virtually flat. We are essentially willing to pay a manufacturer more handsome profits for the increase of functionality their products provide. The end result is that the prices of our smartphones, provided only as an example, have persisted relatively unchanged.

To drive costs of electronics down while also making them smaller, the industry attacked IC packaging. This started in haste in the 1980s and with it came more dependence on PCBs. The packaging technology used was called surface mount. It was now simply impractical to hand solder individual pins (i.e.: terminals) when surface mounting - feasible but impractical. Parts were now being attached to PCBs with a method called wave-soldering and with this, it became essential to develop a PCB to develop one’s concept. It is no longer possible to probe all the pins of ICs whose packages cover their pins.

Students and hobbyists of electronics had a practically insurmountable problem to overcome when surface-mounting came into being. I remember assembling my last Heathkit, it was a multimeter, in the late 1990s, and soon after they stopped selling their world-renown kits altogether. They were nevermore a kit providing company; “the last of the Mohicans”.

As I mentioned, electronics’ costs have been on a downward trend and this enabled something fantastic in the industry of electronics that was yet to occur. It became possible to buy circuit functionality in the form of circuit boards themselves. Whereas the IC has its functionality, it most often requires a complement of other components to make it work. These consist of power supply chips, clocks, host controllers, etc. In the form of a PCB, a completely working subsystem could be obtained and at a cost that is not prohibitive. Some of these PCBs are called modules and still, others are called System in Packages (SiPs).

In addition to the IC producers providing these new PCBs to allow potential customers to evaluate their technology, a new breed of electronics providers came into existence. These are the “maker professional” companies like Mikroe (aka Mikroelektronika), Adafruit, Seeed, SparkFun, and others. Now, to develop a concept using the world’s most sophisticated electronics is once again simple.

There are thousands of electronic subsystems available that can be used to produce a custom integrated system. These commercial-off-the-shelf (COTS) products are used by professional organizations and amateurs alike. While working for DigiKey, I once noticed that we sold the very same ICs that are on some of the modules that we also sold and I noticed that very large firms were not only buying the ICs, they were buying the modules that contained them! I thought, “Why would a company with the resources to build a product at the lowest, most production, cost-efficient way buy them in a little more expensive form-factor as a PCB?'' and I realized some reasons they might do this.

Number one is that a module offers higher value in that, in the case of an RF module, it can be “pre-certified” by governing bodies such as the Federal Communications Commission (FCC). Compliance testing is expensive, taking lots of time and money. Second, is time-to-market. If you are uncertain about the size of a market, it is best to test it sooner than later. If the market exists in sufficient size, a redesign can be undertaken to reduce the cost of the product with lower-level design methodologies. A third reason is to accommodate product variation. With modular subsystems, a product’s feature set and price points can be more easily varied. A point I wish to make is that if electronic subsystems are cost-effective for those firms having the resources to design at the lowest levels of electronics, they are certainly good enough for amateurs and students but the story doesn’t end here.

Among the universe of modular subsystems are a variety of interfaces. The most popular of these are the Serial Peripheral Interface (SPI), Inter-Integrated Circuit (I²C), Analog, quasi-analog Pulse-Width Modulated (PWM), Universal Asynchronous Receiver Transmitter (UART), and Parallel. Of these, only the last one has a broad and varying range of pinouts. Probably 95% or more of modular subsystems do not require a parallel interface and this has meant that subsystems have a small number of pins themselves which keeps their cost and their price low.

Mikroe, owing to the popularity of interfaces above, created their MikroBUS standard and makes it freely available for anyone to use (see Figure 1). IC manufacturers are adopting this subsystem interface in increasing numbers. I believe Microchip was the first to adopt the MikroBUS standard on their evaluation and development boards. They did this because there are over one thousand modules available that are based on the MikroBUS. Depending on how many MikroBUS sites are on one’s board, a virtually unlimited number of concepts can be developed or evaluated without having to wire, rewire, or assemble any PCBs. Because the MikroBUS is now a broadly accepted standard that specifies both the electrical interface and the physical attributes of a board, it has once again become simple to implement concepts at nearly any level of functionality and flexible sophistication inexpensively. But that is not all.

Figure 1. MikroBUS standard. (Image source: Mikroelektronika)

Mikroe is a development tool company. More than making boards using their MikroBUS standard that they call “Click” boards, they also make development tools. Among these tools is one called “CodeGrip.” CodeGrip has a WiFi interface in addition to a USB interface. Over either one of these connections, one can write and debug the software that integrates whatever subsystems exist in a design. Being WiFi-connected means having an interface that is easily bridged to the internet. They have done just that with a system they call Planet Debug.

Planet Debug enables anyone with Mikroe’s integrated development environment (IDE) installed on their personal computer and an internet connection to access remote hardware anywhere in the world. In fact, Mikroe will configure its hardware with any Click boards that you request. This means technology advancement has now reached a point where you do not need to develop or wire any of your own hardware to develop your concept or learn whatever technology you wish to understand more thoroughly.

It’s a happy time to be interested in or to learn about electronics. My contribution to this story ends here for now, but it is you who can write the rest of it by continuing to develop your own concepts.