Light up all kinds of LED

If Hello World is the beginning of religious programming for software programmers, Blink Led is the same for hardware programmers. All hardware programming starts with lighting a lamp.

So we started to prepare our hardware, and I was using a beta version 1.3. It is sufficient for the purposes of this chapter, and is common to subsequent boards. Therefore, we pay attention to progressive, first a lamp, and then a row of lights.