Boot problem

[kirelam]

Dear ESP'ers,

I have a awkward problem. I use a D1 mini as a node for my greenhouse environment.
almost every GPIO port is used without any problem with sensors and 1 relay 4 channel. But if i connect the relay,
the ESP will not boot.
I discovered that the ESP works fine with the relay if i connect it the after the ESP has boot.

For the pin layout for the relay i use GPIO: 14, 12, 13, 15.
The only reason i can think of the boot problem is that GPIO 13 and 15 can function as TX/RX and that somehow the Relay
sends a signal back over these pins while booting. This shouldn't be possible, because the relay uses optocouplers, righy?

It works right now, but it is anoying that after a power cut or so i have to disconnect the relay, boot and connect it again.

Anyone an idea and/experience/or a solution?


Many regards,
Kirelam

[grovkillen]

https://www.letscontrolit.com/wiki/inde ... figuration

You should measure GPIO 15 during power on and see if it is LOW. If it is HIGH the unit will not boot. I guess the relay might give a signal HIGH on boot?

[Shardan]

The only reason i can think of the boot problem is that GPIO 13 and 15 can function as TX/RX and that somehow the Relay
sends a signal back over these pins while booting. This shouldn't be possible, because the relay uses optocouplers, righy?

As grovkillen wrote, i think that GPIO15 is the one.

Optocouplers have an input side. If that Input is connected to "High" it can give a "high" signal to the ESP.
OC's should isolate the relay from the ESP circuit (only as long as you use separate power supplies!).
Nevertheless the voltage driving the LED of the OC can infuence the ESP.

Regards
Shardan