ESP8266 Community Forum

- Mon Nov 09, 2020 3:24 pm #89372 I am working on a simple circuit (for debugging purpose) which switches a 3V3 relay every second through the Esp-01 GPIO2 pin. The power supply comes from the USB to ESP-01 adapter (but the same happens with another power supply)

This circuit is the following:

Code: Select all  **ESP8266-01:**
    VCC <--> 3V3 power supply
    GND <--> GND (power supply)
    CH_PD <--> 3V3 power supply
    GPIO2 <--> IN (relay)
   
    **3V relay:**
    VCC <--> 3V3 power supply
    GND <--> GND (power supply)
    IN <--> GPIO2 (ESP-01)

The relay is mounted on a power extension cord, on which I can connect various devices.

Here is my circuit diagram (the breadboard is not represented):

My sketch is the following:

Code: Select all  #include <ESP8266WiFi.h>
   
    const int switch_pin = 2;
    int state = 0;
   
   
    void setup() {
      Serial.begin(115200);
   
      WiFi.forceSleepBegin();
   
      pinMode(switch_pin, OUTPUT);
    }
   
   
   
    void loop() {
   
      if (state == 0){
        digitalWrite(switch_pin, HIGH);
        state = 1;
        Serial.println("1");
      }
   
      else{
        digitalWrite(switch_pin, LOW);
        state = 0;
        Serial.println("0");
      }
      delay(1000);
    }

which produces, on the serial:

Code: Select all  0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
   
     ets Jan  8 2013,rst cause:4, boot mode:(3,7)
   
    wdt reset
    load 0x4010f000, len 3584, room 16
    tail 0
    chksum 0xb0
    csum 0xb0
    v2843a5ac
    ~ld
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
    0
    1
   
     ets Jan  8 2013,rst cause:4, boot mode:(3,7)
   
    wdt reset
    load 0x4010f000, len 3584, room 16
    tail 0
    chksum 0xb0
    csum 0xb0
    v2843a5ac
    ~ld

Thus, sometimes, the Esp-01 resets and, sometimes it cannot "recover" from such resets.

However, when I disconnect the extension cord (from the electrical outlet in the wall), the relay switches indefinitely as expected (I do not know if it's a clue to solve my problem).

I tried with 2 relays and 2 Esp-01 and always got the same behaviour.

Would you have any idea about the origin of such a problem?