1.how to use 1 gpio pin to drive raspberrypi power-on-off ... · tutorial 1 how to use 1 gpio pin...

Tutorial www.52pi.com

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Howtouse1GPIOPintodriveRaspberryPiPower-on-off-statuslightThedefaultindicatorlightofRaspberryPiistheredLEDlightnexttothepowerlight.Aslongastheraspberrypiispoweredon,itwilllightup.Itishardforustoknowwhethertheraspberrypiisonoroff.Itisevenhardertonoticethedifferencewhenyoufittheboardintoacase.Soifyouwanttoplacetheindicatorlightoutsidethecase,youmaycheckoutthistutorial.

ElectronicComponents：

1*RaspberryPi3ModelB1*RedLEDlight1*220Ohmresister1*Breadboard 2*Male/femaleDuPontJumpWire

InstallationDiagram:

ConnecttheGPIO26Pinsto220Ohmresistorfirst.Thenconnectittothereddiode.

Youmayrefertothisdetaileddiagram:

Tutorial www.52pi.com

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ConfigurationModification:First thing first, run a command to boost the function of Device Tree which will enable yourraspberrypitobecompatiblewithmoredevices.Takealookattheuserguide:sudovim.tiny /boot/overlay/READMESearchforgpio-poweroff Poweroffmeans that the indicator lightwill not light upwhen the system is shutdown. You caneasliytelliftheraspberrypiisturnedoffproperlybycheckingtheindicatorlight.ThedefaultIOintheofficialusermanualisdefinedasIO26andthelatestsystemhasgotwiringPi.ItisveryeasyforyoutosetupandyoumaytakethissetupasthewarmupfortheApplicationKit.HereisthescreenshotfortheofficialREADME:

It is loaded by editing /boot/config.txt and by adding this command for module initialization:dtoverlay=gpio-poweroff,gpiopin=26,active_low Whenitisupdated,restarttheRaspberryPi：sudo sync sudo init 0Theindicatorwilllightupwhenthesystemisrunninganditwillbeturnedoffasthesystemisshutdown.Inthisway,youcaneasilytellthestatusoftheRaspberryPi.WhenyouDIYsomeinterestingapplications,youcanplacetheindicatoroutsidetoevaluatethestatusofthewholeoperation.