Noob here, I have purchased a relay module (see pic below), and was wondering if I needed to add any other protection components to the Pi. Through my limited research, I found that using a diode, transistor and resistor can protect the PI's GPIOs from spikes in current, however, it seems the module is pre-equipped with all three of these components, so do I need to do anything further to protect my Pi? Or can I attach the relay directly to the Pi's GPIO's?

I have tried using the relay directly with the Pi, and it seems to work just fine, however just wanted to confirm before I attach a load to the relay.


  • 1
    A link to the relay's "data sheet" would help us give you a reliable answer. Consider editing your question to add that.
    – Seamus
    Mar 9, 2021 at 17:12
  • 1
    (1) Keyes 5V Relay 5-12V TTL Signal 1 Channel Module High Level Expansion Board - US$3/3 pcs banggood.com/… (2) Keyes SR1y Relay module circuit (tlfong01' comment: High trig, good for Rpi) techydiy.org/keyes-sr1y-relay-module
    – tlfong01
    Mar 10, 2021 at 2:22

2 Answers 2


The relay module should have all the protection needed built-in.

No need to worry.

However the relay itself is marked as 5V so may not be reliably triggered from the 3V3 Pi logic. If the module specs mention 3V3 logic is enough you will be fine.


Most of these appalling "designed" modules REQUIRE 5V to control and put 5V on the GPIO. See Can you use a 5V Relay Module with the Pi?

Without details it is impossible to say, but there appear to be insufficient components for a proper module.

It is simple to test by measuring the voltage on the control input (unconnected) if 5V (or indeed any significant voltage) they are unsuitable.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.