Hi all!

I want to switch on a 5v relay with a 3.3v signal.

I have my ESP8266 running off a 3.3v linear regulator (LM1117T). The source is a USB 5v capable of delivering 500mA. Shoudn't i be able to use this 5v signal to control the relay?

I have tried a lot of setups but without luck! I could really need some help.

I have a MOSFET (IRL540N) and a BJT (BC547).
The relay is 2 relay module.

 

If your relay coil can operate a little bit below 5V you can probably use the USB 5V supply to power it.
Can you provide some information about your relay:

• Pull-in voltage
• Resistance

The actual datasheet would be even better.

I guess that is enough. Which output on the ESP8266 are you trying to use?

 

Please post details of the relay module.
This may already include driver circuitry for the relay.

 

Please post details of the relay module.
This may already include driver circuitry for the relay.

The relay is here: http://www.everbuying.net/product1160582.html
I can't really find the datasheet I'm sorry.

If your relay coil can operate a little bit below 5V you can probably use the USB 5V supply to power it.
Can you provide some information about your relay:

• Pull-in voltage
• Resistance

The actual datasheet would be even better.

I guess that is enough. Which output on the ESP8266 are you trying to use?

I have tried to power the relay with 5v from the USB cable, and then tried to send a 3.3v signal which doesn't work. I'm trying to use the GPIO2 pin on the ESP8266.

 

On the JD-VCC, VCC, GND connector remove the link and connect VCC to your +5V and GND to your GND.
On the other connector at that end of the board connect:
GND to your GND
VCC to +3.3V
IN1 to your GPIO2
IN2 to another GPIO if you want to use both relays.
I believe (but cannot be certain from the module description) that taking IN1 or IN2 low will operate the relay and taking them high will release the relay.