Arduino: A Technical Reference

Chapter 11. Project: A Programmable Signal Generator

Almost every electronics lab, be it large or small, needs signal sources. In some cases these might be simple sine wave generators, and some situations might call for more complex instruments like a function generator. The signal generator described in this chapter, shown in Figure 11-1, is capable of both sine and square wave outputs up to 40 MHz.

Figure 11-1. Homemade DDS signal generator

Of course, you could also purchase a signal generator. Prices vary, depending on the frequency range, features, and capabilities. You can find signal and function generator kits for anywhere from about $6 to around $50 for a device like the one shown in Figure 11-2. At the other end of the scale are commercial high-end instruments costing hundreds or thousands of dollars, or even more (for example, $72,000 for a used 20 GHz multifunction arbitrary waveform generator).

Figure 11-2. FG085 function generator kit (assembled)

While the kits are fine for generating waveforms, they may not have all the features or capabilities you want or need. They are, after all, someone else’s idea, and that person may have a different notion of what makes a signal generator useful. By building it yourself you can get exactly what you want, and you can modify ...