====================== Looping over hardware ====================== In this chapter we learn about looping using hardware (simulation). One NeoPixel at a time ----------------------- .. figure:: img/oneneoatatime.gif The `cpx.pixels` can be accessed by index numbers, from 0 to 9. This way, we can turn on one NeoPixel at a time. .. code-block:: python :linenos: # import CPX library from adafruit_circuitplayground.express import cpx import time BLUE = (0, 0, 255) i = 0 while True: # start your code here if i == 10: time.sleep(10) continue cpx.pixels[i] = BLUE i += 1 time.sleep(0.5) On line number *7*, we declared a variable which selects the correct NeoPixel, and then on line number 14 we are turning on that NeoPixel to Blue color, and then increasing the variable to go to the next NeoPixel. The conditional *if statement* on line 11 makes sure that when we turn on all the lights, we sleep for 10 seconds and continue to do so. First Red and then Blue ------------------------ .. figure:: img/redthenblue.gif Here using two for loops, we are first turning on each NeoPixel in Red and then in Blue. .. code-block:: python :linenos: # import CPX library from adafruit_circuitplayground.express import cpx import time RED = (255, 0, 0) BLUE = (0, 0, 255) while True: for i in range(0, 10): cpx.pixels[i] = RED time.sleep(0.5) time.sleep(0.5) for i in range(0, 10): cpx.pixels[i] = BLUE time.sleep(0.5)