This chapter introduces the Raspberry Pi LEDs and header strips. These are important interfaces from the Pi to the outside world. You may want to use a bookmark for Table 4-5, which outlines the GPIO (general purpose input/output) pins on the modern header strip P1.
Status LEDs
The Raspberry Pi has different sets of LED indicators, depending upon the model. Table 4-1 provides an overall reference chart.5 The Raspberry Pi Zero and Zero W have been lumped together.
Table 4-1
Table of Raspberry Pi LED Indicators
LED | Color | A | A+ | B | B+ | Pi 2 | Pi 3 | Zero/W |
|---|---|---|---|---|---|---|---|---|
OK/ACT | Green | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
PWR | Red | Yes | Yes | Yes | Yes ... |
