Relay High On Boot

Question

Relay High On Boot

shakirhussain78652 opened this issue 3 years ago · comments

shakirhussain78652 commented 3 years ago

I am trying to use NODEMCU ESP8266 V2 and a 5v, 4 channel relay module to be turned on wirelessly via a mobile app.
However every time I power on the circuit. All the relays get activated.
I have tried every pin from D1 TO D7. Still facing the same problem.
Please help.

Chathuranga · Answer 1 · Sun Sep 12 2021 10:38:40 GMT+0800 (China Standard Time)

can't tell anything without seeing the code.

Lukáš Voborský · Answer 2 · Sun Sep 19 2021 02:53:53 GMT+0800 (China Standard Time)

Isn't it due to pin states during boot?
https://www.esp8266.com/viewtopic.php?f=32&t=16141

Hey,
GPIOs 4 and 5 are the only ones that are always high impedance. All others do have internal pull-ups or are even driven low/high during boot.

GPIOs 3, 12, 13 and 14 pulled HIGH during boot. Their actual state does not influence the boot process.

GPIOs 0, 1, 2 and 15 are pulled HIGH during boot and also driven LOW for short periods.
The device will not boot if 0, 1 or 2 is driven LOW during start-up.

GPIO 16 is driven HIGH during boot, don't short to GND.

Marcel Stör · Answer 3 · Sun Sep 19 2021 18:08:25 GMT+0800 (China Standard Time)

Nothing the NodeMCU firmware can influence.

Terry Ellison · Answer 4 · Mon Sep 27 2021 08:30:39 GMT+0800 (China Standard Time)

@shakirhussain78652 I drive 4 power SSRs directly from my ESP board. These require 5V @ 50 mA IIRC. The way I do this is to use a MSP23008 with its VCC at 5V direct from my 5V PSU. It interfaces to the ESP via I2C This is at a 3.3V float high reference with both ends doing pull down to GND as necessary. The MSP23008 works fine with 0/3.3V signalling. An no startup pulse issues.