The maximum current we can safely use with a GPIO pin configured for output is 16 mA. However, there is a configurable aspect of GPIO pins, which means that, by default, we should not use more than 8 mA per GPIO. This limit can be configured so that it goes up to 16 mA, but this is beyond our scope. Ideally, we want to be moving toward external circuits when more current is needed rather than pushing the pins higher and higher. We will learn how to do this in Chapter 7, Turning Things On and Off.
While we want to limit a single GPIO output pin to 8 mA, we should not exceed a combined total of ~50 mA over multiple GPIO pins. When it comes to GPIO input pins, we should limit the current to 0.5 mA for safe operation when connecting an external input device or component. Connecting an input GPIO pin directly to the Raspberry Pi's +3.3 V or GND pin is fine as the measured current is approximately 70 microamps. (We&apos...