ESP8266 Community Forum

- Mon Jun 25, 2018 4:48 pm #76631 I am attempting to implement a light sleep mode on an esp8266 (feather huzzah variety) which, when a button is pressed, wakes the system up so that it can continue its normal task.

I cobbled together some code from this post (https://arduino.stackexchange.com/questions/48873/wake-up-esp8266-with-multiple-gpios) , which I've slightly modified:

Code: Select all    #include <ESP8266WiFi.h>
    #include <WiFiUdp.h>
    #define WAKE_PIN 5
   
    extern "C" {
        #include "gpio.h"
    }
   
    extern "C" {
        #include "user_interface.h"
    }
   
    void setup(){
        Serial.begin(115200);
        Serial.println("Setup");
       
        pinMode(WAKE_PIN, INPUT_PULLUP);
        gpio_init(); // Init GPIO pins
    }
   
    void loop(){
        Serial.println("Do something...");
        Serial.println(digitalRead(WAKE_PIN));
        delay(500); //random delay for that stuff to be done
       
        if(!digitalRead(WAKE_PIN)){ //if we don't detect pin, sleep
            sleep();
        }
        delay(1000);
       
    }
   
    void sleep(){
        Serial.println("Going to sleep...");
        delay(10);
        wifi_fpm_set_sleep_type(LIGHT_SLEEP_T); // set sleep type
        gpio_pin_wakeup_enable(GPIO_ID_PIN(WAKE_PIN), GPIO_PIN_INTR_LOLEVEL);  //LO OR HI?
        wifi_fpm_open(); // Enables force sleep
        wifi_fpm_do_sleep(5000); //Sleep for short time
        delay(100);
        Serial.println("Woke up!");
    }


Here is how I have things wired:



So the setup function works as expected, as well as "do something". The button reads high (1) when it is unpressed, and when I push it, it reads low (0) - which sends the ESP to sleep. In the serial monitor, I see:

Code: Select all    Going to sleep...
    Soft WDT reset
   
    ctx: cont
    sp: 3ffef7a0 end: 3ffef9a0 offset: 01b0
   
    >>>stack>>>
    3ffef950:  0001260d 00000600 3ffee970 4021fc84 
    3ffef960:  00001388 402020ba 402020b1 402020a1 
    3ffef970:  00000000 00000000 3ffee944 40202115 
    3ffef980:  3fffdad0 00000000 3ffee968 402027d4 
    3ffef990:  feefeffe feefeffe 3ffee980 40100710 
    <<<stack<<<
   
     ets Jan  8 2013,rst cause:2, boot mode:(1,6)
   
   
     ets Jan  8 2013,rst cause:4, boot mode:(1,6)
   
    wdt reset


I'm not very experienced with Arduino or Electric Engineering, so I'm not exactly sure what is happening vs. what should happen, but this is my interpretation:

I read somewhere that reset causes are as follows:

Code: Select all    reset causes:
        0:
        1: normal boot
        2: reset pin
        3: software reset
        4: watchdog reset
   
    boot device:
        0:
        1: ram
        3: flash


In which case, if `soft reset` is considered light sleep for the esp, then the `rst cause:2` is expected behavior, as it means it was triggered by pin 5. The `rst cause: 4` i'm not sure about though - watchdog reset. Seems to be a protective mechanism for the device, in which case maybe the reset of this must coincide with the reset triggered by sleep mode and is normal? Or does it indicate a crash? In any case, I have no idea what all the `stack` stuff is, but the system does not restart - I cannot get any further readings from the serial monitor after this.

I'm not sure whether `GPIO_PIN_INTR_LOLEVEL` should be high or low - I couldn't find documentation on this (though I did see it in the GPIO header source file on git.

I [read something where someone else had a similar problem][6] and someone made a reference to adding resistors and making sure GPIO 0 should be high, and 15 should be low. The link they posted was dead, but it made me think of something I read about deep sleep, in which you have to wire RST to 0. I actually tried running a wire between RST and holding to the `#0` pad that's right by the USB port on the feather huzzah, and after that, the code would actually go to sleep, then wake itself up automatically and resume the normal loop function - but what I want is for only the button to wake up the ESP.

I'm stuck from here. Anyone have any ideas of what might be happening and how to fix it?