Designing Embedded Hardware, 2nd Edition

Quick Construction

It is possible to build very simple circuits by just soldering the components together in free space. For example, the leads of a watch crystal can be soldered directly onto the pins of the processor, with the crystal lying across the top of the processor. Wires are soldered onto the pins bringing in ground and power, and connecting the processor's I/O to the outside world. This technique is variously referred to as a rat's nest, bird's nest, or "what the hell is that?" (Figure 6-15).

Figure 6-15. Rat's nest construction of a small microcontroller system

This is a quick-and-dirty method, useful for rapid prototyping of extremely simple circuits. It's not really recommended, but you can get away with it in a pinch. Don't try it with anything that is even slightly complicated or running at any reasonable speed. If you do, you'll spend more time debugging the construction than debugging the actual design or code!

Breadboarding

Breadboards are plastic blocks with arrays of electrically connected holes (Figure 6-16). They are designed to hold DIP (Dual Inline Package) integrated circuits and discrete components. The term "breadboard" dates back to the olden days when valve radios were constructed on a base of solid wood (a cutting board for bread). The term has stuck, and the modern breadboard can still be found in electronics hobbyist stores, and even the occasional ...