IO Pi plus as switch
2035 Views - Created 19/06/2017
The IO Pi Plus will not be able to switch the +2.5V directly as it can only output 5V from its pins. What you will need is an external transistor to act as a switch.
The circuit below shows what you need to use. An NPN transistor is connected between the +2.5V and GND acting as the switch. A 500R resistor is connected between the IO Pi output and the transistor gate to limit the current to 10mA so that when the IO Pi output goes high it will turn on the transistor allowing current to flow. The 10K resistor is there to pull the gate low when the IO Pi output goes low ensuring the transistor fully switches off.
You will need to connect the ground on your other device to the ground on the Raspberry Pi to ensure they both have a common ground.
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