sd-read

C++ implementation

// This is the old sd-log patch migrated to the new v0.35 syntax method according to https://xod.io/docs/guide/migrating-to-v035/

#pragma XOD evaluate_on_pin disable
#pragma XOD evaluate_on_pin enable input_R
#pragma XOD error_raise enable



#include <SPI.h>
#include <SD.h>
size_t strlcpy(char *dst, const char *src, size_t size)
// Thanks to Adam Rosenfield for this funcion, strlcpy
{
    size_t len = 0;
    while(size > 1 && *src)
    {
        *dst++ = *src++;
        size--;
        len++;
    }
    if(size > 0)
        *dst = 0;
    return len + strlen(src);    
}


node {
    
    bool begun;
    char str[64] ;
 
    CStringView view = CStringView(str);
    
void evaluate(Context ctx) {
    if (!isInputDirty<input_R>(ctx))
        return;


    if (!begun) {
        // First time use, initialize
        auto csPin = getValue<input_CS>(ctx);
        begun = SD.begin(csPin);
    }

    if (!begun) {
        // Initialization failed (wrong connection, no SD card)
        raiseError(ctx);
        return;
    }
    char filename[16] = { 0 };
    dump(getValue<input_FILE>(ctx), filename);
    File myFile = SD.open(filename, O_READ);
    if (!myFile) {
        // Failed to open the file. Maybe, SD card gone,
        // try to reinit next time
        begun = false;
        raiseError(ctx); // Can't open file
        return;
    }

    uint8_t START = getValue<input_START>(ctx);
    uint8_t CAP = getValue<input_CAP>(ctx);
    
    myFile.seek(START);

    uint8_t index = 0;
    //char ch[CAP+1];
   while (myFile.available() && index < CAP){
       char someChar = myFile.read();
      
       str[index] =someChar;
     
        index++;
       str[index] = '\0';
   }
  
    int pos = myFile.position();
    
    //strlcpy(str, ch, sizeof(str));
    
    myFile.close();
    
   emitValue<output_STR>(ctx, XString(&view));
   emitValue<output_DONE>(ctx, 1);
   emitValue<output_POS>(ctx, pos);


}
}