ESP8266 Community Forum

- Sun Dec 04, 2016 2:58 pm #59090 Hi. I'm using ESP8266 Arduino for compiling and uploading my code to NodeMCU 1.0 (ESP-12E Module).
Flash Size: 4M (3M SPIFFS)
CPU frequency: 80 MHz
Upload Speed: 115200
I'm using portable arduino extracted in my D: drive.

I've written this basic code to download 'datalog.txt' file (stored in the root of my SD card).

Code: Select all#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <SPI.h>
#include <SD.h>

const int chipSelect = 4;

const char *ssid = "tiny-esp";
const char *password = "password";

ESP8266WebServer server(80);

String home = "<h1>Hello! from ESP8266!</h1>"
                "<p><a href=\"down\"><button>Download</button></a>";

void handleRoot() {
    server.send(200, "text/html", home);
}

void handleDownload() {

    File dataFile = SD.open("datalog.txt");
    int fsizeDisk = dataFile.size();
    Serial.print("fsizeDisk: ");
    Serial.println(fsizeDisk);

    size_t fsizeSent = server.streamFile(dataFile,"text/plain");

    Serial.print("fsizeSent: ");
    Serial.println(fsizeSent);

    dataFile.close();
}


void setup() {
    delay(500);
    Serial.begin(115200);
    Serial.println();

    WiFi.softAP(ssid, password);

    IPAddress apip = WiFi.softAPIP();
    Serial.print("Please visit: \n");
    Serial.println(apip);

    // see if the card is present and can be initialized:
    if (!SD.begin(chipSelect)) {
        Serial.println("\nCard failed, or not present");
        // don't do anything more:
        return;
    }
    Serial.println("\nCard Initialized.");

    server.on("/", handleRoot);
    server.on("/down", handleDownload);
    server.begin();
    Serial.println("HTTP server started");
}

void loop() {
    server.handleClient();
}


But, when I press the 'Download' button, the ESP hangs and then restarts as displayed below (from my Serial Monitor):

Code: Select allPlease visit:
192.168.4.1

Card Initialized.
HTTP server started
fsizeDisk: 28600

Panic D:\arduino-1.6.9-windows\arduino-1.6.9\hardware\esp8266com\esp8266\cores\esp8266\core_esp8266_main.cpp:98 __yield

ctx: sys
sp: 3ffffc80 end: 3fffffb0 offset: 01b0

>>>stack>>>
3ffffe30:  3ffefdf4 000003b9 000003b9 4010020c 
3ffffe40:  00000000 3ffe9645 00000001 4020815d 
3ffffe50:  3ffefdf4 00000481 3fff0d50 402077e5 
3ffffe60:  3fff337c 00000b68 00000000 40207823 
3ffffe70:  3fff3a74 3fff1480 3fff3a74 3fff1474 
3ffffe80:  3fff337c 00000b68 3fff307c 40202a57 
3ffffe90:  3fff3a74 00000b68 3fff2cfc 40202c07 
3ffffea0:  00000000 3ffe9704 3fff337c 3fff1474 
3ffffeb0:  3fff337c 3fff147c 3fff2cfc 40202d34 
3ffffec0:  3ffeead0 0883f900 3fff1478 40202d54 
3ffffed0:  3fff337c 3fff147c 3fff1478 4022670d 
3ffffee0:  00000000 0104a8c0 00000010 00000000 
3ffffef0:  00000000 00000010 3ffefe40 40221001 
3fffff00:  40210000 00000000 0000007d 3fff151c 
3fffff10:  3ffebae4 3fff1520 3fff3434 40224b39 
3fffff20:  3fff1370 3fff1fac 3fff1fac 4021547e 
3fffff30:  40215972 3ffed310 3ffebabc 3fff1fac 
3fffff40:  3ffebad6 00000000 3fff3434 40223f35 
3fffff50:  0204a8c0 3ffee318 02a93dee 00000000 
3fffff60:  40104b62 02a93dee 3ffeead0 60000600 
3fffff70:  4022d230 3ffeeaa8 3ffeead0 0884220c 
3fffff80:  4022d256 3fffdab0 00000000 3fff2004 
3fffff90:  3fffdc90 00000000 3fff3434 4022ce8b 
3fffffa0:  40000f49 3fffdab0 3fffdab0 40000f49 
<<<stack<<<

 ets Jan  8 2013,rst cause:2, boot mode:(3,7)

load 0x4010f000, len 1384, room 16
tail 8
chksum 0x2d
csum 0x2d
v00000000
~ld

Please visit:
192.168.4.1

Card Initialized.
HTTP server started


I don't understand the verbatim error dump. What am I doing wrong?
Please help!