Effortless SPIFFS not compiling

Projects Programming
1

Hi all,

I'm using the Effortless SPIFFS library:

#include <Effortless_SPIFFS.h>

Writing to SPIFFS using this tool seems to be a breeze, but I haven't been able to test it as the reading command is failing to compile. As per the documentation on eSPIFFS I'm using this to make the retrieve call:

    if (fileSystem.openFromFile("mqtt_ip.txt", mqtt_ip)) {
        Serial.println("Got mqtt_ip value");
    }

But I'm getting an error when compiling:
no matching function for call to 'eSPIFFS::openFromFile(const char [12], char [11])'

Here is the Github site for it: GitHub - thebigpotatoe/Effortless-SPIFFS: A class designed to make reading and storing data on the ESP8266 and ESP32 effortless

Any idea what I'm doing wrong here?

2

Since you didn't both to show us all your code, I have to guess that 'mqtt_ip' is a char array. From the library's README, you can see the types that are supported for the second argument to openFromFile, char array is not one of them:

// Definitions
bool openFromFile(const char*, &bool);
bool openFromFile(const char*, &float);
bool openFromFile(const char*, &double);
bool openFromFile(const char*, &signed char);
bool openFromFile(const char*, &unsigned char);
bool openFromFile(const char*, &signed int);
bool openFromFile(const char*, &unsigned int);
bool openFromFile(const char*, &signed short);
bool openFromFile(const char*, &unsigned short);
bool openFromFile(const char*, &signed long);
bool openFromFile(const char*, &unsigned long);
bool openFromFile(const char*, &char*);
bool openFromFile(const char*, &const char*);
bool openFromFile(const char*, &String);
bool openFromFile(const char*, &std::string);
bool openFromFile(const char*, &ArduinoJson::DynamicJsonDocument);

Looking in Effortless_SPIFFS.h, it seems you may want to pass a 'char *' or a 'const char *'. The function should then load the from the file and store in a local static buffer. It will then set your pointer to point at this buffer. I'd think you'd want to copy the contents out of that buffer before calling openFromFile again.

3

gfvalvo:
you may want to pass a 'char *' or a 'const char *'

Spot on. Your guess was right about my char array. I just didn't realise char* is not the same. Novice coder.

Thankyou :slight_smile: