yes it works !

thants a lot

no. there is only the gpio plug on the raspberry nothing else.

i should plug power supply ground to rpi ground ?

hello everyone, i've got a problem with raspberry , gpio and a relay. i choose an external power supply 5v for a little relay board. Relay will be command by gpio 23. The relay didnt commute when i asked it when it is powered by external power supply but works when it is powered by 5v raspberry gpio...