Raspberry Pi_Eng_25.2.3 Precautions and Features in Using GPIO

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Published Book on Amazon

All of IOT Starting with the Latest Raspberry Pi from Beginner to Advanced – Volume 1
All of IOT Starting with the Latest Raspberry Pi from Beginner to Advanced – Volume 2

출판된 한글판 도서

최신 라즈베리파이(Raspberry Pi)로 시작하는 사물인터넷(IOT)의 모든 것 – 초보에서 고급까지 (상)
최신 라즈베리파이(Raspberry Pi)로 시작하는 사물인터넷(IOT)의 모든 것 – 초보에서 고급까지 (하)

Original Book Contents

25.2.3  Precautions and Features in Using GPIO

 

●   Precautions in using GPIO pin

 

■    When powering Raspberry Pi, make sure that metal object does not touch the GPIO pin.

■    Do not supply more than total 250mA current from 5V power pin. 

■    Do not supply more than total 50mA current from 3.3V power pin.

■    Do not supply higher than 3.3V to all GPIO pins at the input.

■    Do not use more than 3mA current per pin at the output.

■    Do not supply higher than 5V power to Raspberry Pi.

 

 

●   Features of GPIO Pin

 

■    If no current flows through the pin, you can not determine what the initial state is. That is, it is floating.

■    The pin remembers the last state until the system is shut down. When you exit the program after issuing a command to turn on the pin, the pin remains on until you release another command.