WeMOS R1 D2 issuing "wdt reset" messages

[dspdon]

Basic Infos

Running WiFiScan.ino example with WeMOS R1 D2, started failing with "wdt reset" message

Hardware

Hardware: WeMos R1 D2

Description

Ran WiFiScan.ino example with WeMOS R1 D2, ran fine a few times. I changed serial port rates, ran fine. Changed back, code started failing with message:

ets Jan 8 2013,rst cause:4, boot mode:(1,6) wdt reset

Sometimes a stack dump would also display repetitively.

Settings in IDE

Module: ?Generic ESP8266 Module? Flash Size: ?4MB/1MB? CPU Frequency: ?80Mhz? Flash Mode: ?qio? Flash Frequency: ?40Mhz? Upload Using: ?OTA / SERIAL? Reset Method: ?ck / nodemcu?

Sketch

/*

• This sketch demonstrates how to scan WiFi networks.
• The API is almost the same as with the WiFi Shield library,
• the most obvious difference being the different file you need to include: */

  include "ESP8266WiFi.h"

void setup() { Serial.begin(115200);

// Set WiFi to station mode and disconnect from an AP if it was previously connected WiFi.mode(WIFI_STA); WiFi.disconnect(); //ESP.wdtDisable();

delay(100); }

void loop() { Serial.print(F("Scanning ... "));

int n = WiFi.scanNetworks(); if (n == 0) { Serial.println(F("no networks")); } else { Serial.print(n); Serial.println(F(" networks")); for (int i = 0; i < n; ++i) { Serial.print(i + 1); Serial.print(": "); Serial.print(WiFi.SSID(i)); Serial.print(", ch "); Serial.print(WiFi.channel(i)); //WiFiPhyMode_t pm = WiFi.getPhyMode(); Serial.print(", "); Serial.print(WiFi.RSSI(i)); Serial.print(" dBm, "); Serial.println((WiFi.encryptionType(i) == ENC_TYPE_NONE) ? "" : "*"); delay(10); } } Serial.println();

delay(5000); }

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[igrr]

Which version of the core are you using (2.1.0 or latest git?)

[dspdon]

How do I determine which core I am using?

On Mar 12, 2016, at 12:25 PM, Ivan Grokhotkov notifications@github.com wrote:

Which version of the core are you using (2.1.0 or latest git?)

— Reply to this email directly or view it on GitHub.

[krzychb]

@dspdon,

1. Go to Tools > Board: (Board Name) > Boards Manager.
2. Scroll down to esp8266
3. You should see version N.N.N INSTALLED (see below).
4. If version is not listed, you are likely using git version

Krzysztof

[dspdon]

I have version 2.1.0:

[image: Inline image 1]

On Tue, Mar 15, 2016 at 1:04 AM, Krzysztof notifications@github.com wrote:

@dspdon https://github.com/dspdon,

1. Go to Tools > Board: (Board Name) > Boards Manager.
2. Scroll down to esp8266
3. You should see version N.N.N INSTALLED (see below).
4. If version is not listed, you are likely using git version

Krzysztof

[image: core version] https://cloud.githubusercontent.com/assets/12953787/13768100/577aeeaa-ea72-11e5-983b-bab3d03bfe01.png

— You are receiving this because you were mentioned. Reply to this email directly or view it on GitHub: https://github.com/esp8266/Arduino/issues/1757#issuecomment-196662818

[yomasa]

delay too long in loop maybe?

[242617]

Removing writing to Serial is the solution in my case.

[devyte]

Scanning is being done on every loop pass, including print out to Serial. The execution of the loop body should be spaced out by polling millis(), and actually do a scan every e.g.: 6s. Also, the relevant underlying code has changed quite a lot since this issue was opened. Closing.