ESP8266 Community Forum

Hello.

I have simple ESP arduino question .
I have web server and handle POST function.

I just want to save file sent by POST to SPIFFS.

When upload starts I try to open fiel for wrirting fsUploadFileconf= SPIFFS.open(CONF_FILE, "w");).

It generates exception.

Funny thing but openning for read works fine fsUploadFileconf= SPIFFS.open(CONF_FILE, "r");

My code below:

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>

#include "FS.h"

const char* ssid = "xxxxxxxxxxxxxxxxx";
const char* password = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";

ESP8266WebServer httpServer(80);

#define CONF_FILE "/conf/conf.props"

File fsUploadFileconf;

void handleConfUpload()
{

Serial.printf("handleConfUpload :%s\n",httpServer.uri().c_str());

// handler for the file upload, get's the sketch bytes, and writes
// them through the Update object
HTTPUpload upload = httpServer.upload();

if(upload.status == UPLOAD_FILE_START){

Serial.printf("UPLOAD_FILE_START\n");

Serial.printf("uri: %s \n",httpServer.uri().c_str());

fsUploadFileconf= SPIFFS.open(CONF_FILE, "w");

if(!fsUploadFileconf)
{
Serial.printf("open file failed %s\n" ,CONF_FILE);
return;
}

} else if(upload.status == UPLOAD_FILE_WRITE){

Serial.printf("UPLOAD_FILE_WRITE\n");

Serial.printf("Writing upload.currentSize %d \n",upload.currentSize );
Serial.printf("Writing buf %s \n",upload.buf);

fsUploadFileconf.write((const uint8_t*)upload.buf, 3);
//holds the current upload

fsUploadFileconf.write(upload.buf, upload.currentSize);

} else if(upload.status == UPLOAD_FILE_END){

Serial.printf("UPLOAD_FILE_END\n" );
fsUploadFileconf.close();

} else if(upload.status == UPLOAD_FILE_ABORTED){

Serial.println("UPLOAD_FILE_ABORTED");
}
delay(0);

}

void handleConfUploadAfterFinished()
{
Serial.println("handleConfUploadAfterFinished");

httpServer.sendHeader("Location","/");
httpServer.sendHeader("Cache-Control","no-cache");
httpServer.send(302);

}

void handleRoot() {

httpServer.send(200, "text/plain", "hello from esp8266!");

}

void setup(void){

SPIFFS.begin();
Serial.begin(115200);
WiFi.begin(ssid, password);
Serial.println("");

// Wait for connection
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.print("Connected to ");
Serial.println(ssid);
Serial.print("IP address: ");
Serial.println(WiFi.localIP());

if (MDNS.begin("esp8266")) {
Serial.println("MDNS responder started");
}

httpServer.on("/", handleRoot);

httpServer.on("/inline", [](){
httpServer.send(200, "text/plain", "this works as well");
});

httpServer.on("/confupload", HTTP_POST, handleConfUploadAfterFinished, handleConfUpload);

httpServer.begin();
Serial.println("HTTP server started");
}

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

Serial output:

...
UPLOAD_FILE_START
uri: /confupload

Exception (2):
epc1=0x3ffef7e0 epc2=0x00000000 epc3=0x00000000 excvaddr=0x3ffef7e0 depc=0x00000000

ctx: sys
sp: 3ffef630 end: 3fffffb0 offset: 01a0

>>>stack>>>
3ffef7d0: 000c3a05 000c3a04 00000001 4020ced8
3ffef7e0: ffffff7e 3ffef820 00000000 00000004
3ffef7f0: 3fffc718 3ffef820 00000000 3ffef874
3ffef800: 4020cfb5 4020cfaa 000c7804 00000004
3ffef810: 000c7805 000c7804 00000001 4020ced8

Can you help me and tell why I can not open file for writig during file upload ?

You first need to figure out what is the stacktrace of the exception.
Install teh EspExceptionDecoder from https://github.com/me-no-dev/EspExceptionDecoder,
and follow instruction https://github.com/esp8266/Arduino/blob ... ck_dump.md
Then, we can get some clues.
I've done such upload since more than a year and it is working, I don't see obvious mistake in your code yet, except maybe little one unrelated : SPIFFS don't have path, so filename like "/conf/conf.props" is consider as whole name, not path+name.