B4R Question Powering 4 rele module

José J. Aguilar

Well-Known Member
Licensed User
Hi all:

Following with my small project as described here:

I'm having a problem, probably due to voltages or something like that.
When I tested it, I powered the rele with 3.3v, and it worked, the remote was activated. When I received my 4 reles module, I saw they were powered with 5V, and the activation signal was a 3.3V.
My problem is when I power them with a 5V voltage, the ligths power on, but very low (even if the module is not powered, that ligths get on very low when I connect D0, D2 to IN1, IN2, so... some returning voltage?).
When I activate the reles with my app, the ligths turn off (expected behaviour), but the rele doesn't work (I can't here the 'click').

Here is a simplified schema:




Well-Known Member
Licensed User
José, your sch (draw) has GND to Vcc in the relay-PCB (and +5V to GND)

About your error, add a wire between ESP8266-GND and the Relay PCB-GND.

Also note, you can use +5V from the ESP8266 to power the Relay-PCB
Check if Vin = +5V

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