Boron Digital Output HIGH pin Voltage only 2.8v not 3.3v


I am using the most basic form to set a digital output on pin A5 to HIGH but with a volt meter i am only getting 2.8v not 3.3v as the device states for digital high output.

FYI a reading off the 3v3 pin shows 3.3v perfectly.

Is there anything i need to set extra to get 3.3v as the output with digitalWrite(led, HIGH); ?

thank you much !

Welcome to the community :+1:

Have you got anything other than your volt meter connected to that pin?
Do you get the same readings from other pins?

Hi @ScruffR, I do have the same experience. I get around 1.9v out of my A5 or for example D5 pin, while I’ll need 3.3v. Any tips?

The same questions apply here too

GPIO pins on the Boron can only drive about 15mA. If your load is too strong it will overwhelm the output stage of the GPIO and consequently the voltage will “collapse” and your GPIO will eventually get fried.


A LED. Would the pinSetDriveStrength help out? And would you have a code snippet for that?

You need a current limiting resistor for your LED.

Depending on colour your LED will have a specific forward voltage. Subtract that from 3.3V and get the voltage drop you will have to deal with through the current limiting resistor and calculate the value for the resistor according to Ohm’s law to get the desired current through LED & resistor (e.g. 10mA).

Nope, it won’t.


Thanks a million. It works. Even with my knowledge :sweat_smile:

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