ESP8266 Community Forum

- Wed May 20, 2015 12:39 pm #17985 I think the pull-up might be the problem - the module stops responding at restart even if I just connect a wire to it (without connecting it to the relay input). The input must also be pulling it down. On the other hand, the module stops working even if I connect it to the input without restarting.

I also have used a level converter (3.3V ---> 5V) between the GPIO and the input of the relay, but it makes no difference.

- Wed May 20, 2015 12:48 pm #17987

I think the pull-up might be the problem - the module stops responding at restart even if I just connect a wire to it (without connecting it to the relay input). The input must also be pulling it down. On the other hand, the module stops working even if I connect it to the input without restarting.

I also have used a level converter (3.3V ---> 5V) between the GPIO and the input of the relay, but it makes no difference.

If you can locate a schematic of the relay module you should be able to confirm that that's the problem...

- Wed May 20, 2015 2:15 pm #17994 ULN2803

Costs pennies, has the diode build in and is easy to wire up. But the DIP18 might be a little big.

- Wed May 20, 2015 11:03 pm #18015 You can't tell from the picture but I'll assume that there is some sort of transistor on that relay board. The relay you show is a 5V relay and the ESP modules operate at 3.3V so you need a 3.3V relay.

If you have a link to the module you are trying to use we can confirm and recommend the best method to get this to work for you.