I have a relay module exactly like the one on the next page : https://microcontrollershop.com/product_info.php?products_id=5919
I wanted to consult you about the correct way to use it. I connected the 5V port of my RPi to "+", GND to "-" and "S" to GPIO17.
1- In the first measure when directly connecting the module to the RPi, take the current between the gpio port and the "S" (SIGNAL) output, and measure a value of 4 mA.
2- In addition, I made the previous connection but I connected between "s" and the gpio a resistance of 2.2 K, took its current and obtained a value of 0.42 mA.
3- The voltage difference between + and - is 5 V.
4- The voltage between "S" and "-" is 3.30 V.
I could use one of the 2 previous connections (Point 1 or 2), or I should add an additional transistor ?(I have seen several websites but I have doubts about the connection with the module I have). I'm currently using point 2 without problems but I'm afraid of damaging my Rpi.