The gate-source voltage is 20V not 2.5V. Also how much current are you planning to go from drain to source?

Hello, I downloaded and installed a SparkFun library for controlling this camera: https://www.sparkfun.com/products/10061
but when I verified the code I got this error report:

Code:

As of Arduino 1.0, the 'BYTE' keyword is no longer supported.
Please use Serial.write() instead.

on the line of code that looks like this(line 73):

Code:

MemoryCard.file.print(response[i], BYTE);

So I tried this:

Code:

MemoryCard.file.write(response[i]);

but, that didn't work either as I got this error report:

Code:

error: overriding 'virtual size_t Print::write(uint8_t)'

So my question is how do I fix that line to make it Arduino 1.0 compatible?

Thank you, I will try that now. It's the only logical thing left. I really appreciate your help everyone, especially to billroy for sticking with me on this one!

You might have broken something on the Arduino itself, you should try probing the Arduino with a multimeter to see if there's any voltage present on the actual board.

I apologize, what I mean is that it won't print out the new ID to the Serial monitor and after you give it a new money value it won't run the rest of the code to save the file, like it does the first time you run it.

Yeah I edited my previous post it explains what the code is trying to accomplish.

My code is pretty long >130 lines but the problem is the first statement in void loop() so it's pretty easy to find.
I really appreciate any help!
The code is pretty fun to use, just need an Arduino with SD card and SD card shield.
Run the code and open the Serial monitor. Then type in an 8 digit number ID (random numbers will work) and then type in an amount of money, (numbers and terminate the numbers with an 'e', like this --> 123e). It'll create the file and print some stuff. And then it'll ask for another ID again, the problem is when you run through it again it doesn't work, I need the id[] and money[] arrays to be cleared because the code doesn't work with the old values stored there.
I hope this makes sense, feel free to run this code, it's really cool!

Code:

#include <SD.h>
#include <string.h>
byte SD_CS = 4; //Chip select of SD reader
File cust_file; //to call text file
char id[50]; //name of text file
int id_index = 0;
char money[50]; //value in text file
int money_index = 0;
char money_read[50]; //value read from text file
int money_read_index = 0;
float valueFloat; //typecasted valueReceive
int input; //user input
byte id_counter = 0;
byte money_counter = 0;
float old_money, current_money, new_money; //old is stored, current is entered, new is to write
char cl = '\0';
boolean clrd = 0; //only clears memory when data has already been written

void setup(){
  Serial.begin(9600); //open serial port
  Serial.println("Initializing SD Card");
  pinMode(SD_CS, OUTPUT); //CS for SD card
  pinMode(10, OUTPUT); //CS must be an output for SPI to work
    
  if(!SD.begin(SD_CS)){ //tests to see if SD card initialization failed
  Serial.println("SD card initialization failed");
  return;
  }
  Serial.println("SD card initialization success");
    
  Serial.println("Enter in ID:"); //prompts user to enter in a value to store
  id[id_index++] = '/';  // Root directory
}

void loop(){
  while(clrd){ //part that creates the problem!
    memset(id, '\0', 50);
    memset(money, '\0', 50);
    clrd = 0;
  }      
  get_id();
  get_current();
  get_old();
  get_new();
}

void get_id(){ //gets ID(filename) from user to name file
 
  while(Serial.available()){ //read data from Serial port
    input = Serial.read();
    if(input>='0' && input<='9'){
      id[id_index++] = input;
    }
    strcpy(id+id_index, ".txt"); //converts to pointer array
    id_counter++;
  }
  
  if(id_counter>=8){ //if filename complete
    Serial.print("ID Entered is: "); //print id entered to Serial
    Serial.println(id);
    Serial.println("Enter in money:"); //prompt user to enter in money
  }
  else{
   get_id(); //otherwise go back to function
  }
}

void get_current(){ //gets current input from user
  id_counter = 0; //prevents code from repeating itself over and over.
  while(Serial.available()){ //reads data from serial port and save in pointer array
    input = Serial.read();
    if(input>='0' && input<='9'){
      money[money_index++] = input; //saves user input to money index
    }
    else if(input=='e'){
     money_counter = 1;
    }
  }
  if(money_counter==1){
    strcpy(money+money_index, ""); //converts to pointer array
    current_money = atof(money); //current_money is saved from money pointer array after being converted to float
    Serial.print("Money entered is: "); //print money entered to Serial
    Serial.println(current_money);
    Serial.println(" "); //blank line
  }
  else{
   get_current();
  }
}

void get_old(){ //gets old value from file if exists, if file doesn't exist create one first
  money_counter = 0; //prevents code from repeating itself over and over.
cust_file = SD.open(id, FILE_READ); //open file at beginning
  if(!cust_file){ //if file not already present, create one
    cust_file = SD.open(id, FILE_WRITE); //create file
    Serial.print("Created file: "); //prints new file name
    Serial.println(id);
    Serial.println(" ");
  }
  if(cust_file){ //if file is available
 while(cust_file.available()){
            for(byte c=0; c<50; c++){
     money_read[money_read_index++] = cust_file.read(); //store file contents
   }
 }
  old_money = atof(money_read); //stores the array as a float in old_money
  Serial.print("File available, old money stored is: "); //prints old money stored
  Serial.print(old_money);                //in file to Serial Serial.println(old_money); //print old_money
  Serial.println(" "); //blank line
  cust_file.close(); //close file
  }
}

void get_new(){ //get new_money by computing current_money and old_money
  new_money = current_money + old_money;
  if(new_money>=100.0){ //if new_money greater than 100 than print coupon and subtract 100
    new_money -= 100.0;
    Serial.println("You have a $5 discount!");
    Serial.print("You have $");
    Serial.print(new_money);
    Serial.println(" left.");
    Serial.println(" ");
  }
  else if(new_money<100.0){ //if new_money less than 100 print new_money
    Serial.print("You have $");
    Serial.print(new_money);
    Serial.println(" now.");
    Serial.println(" ");
  }
  cust_file = SD.open(id, FILE_WRITE);
  cust_file.print(new_money);
  cust_file.close();
  Serial.println("File written."); //shows user that file has been successfully written  
  Serial.println(" "); //prints blank line
  Serial.println("Enter ID:"); //prompts user to enter next ID
  clrd = 1; //lets the data in id and money arrays clear
  loop();
}

Yeah measure in seconds. But it's not a very precise way to get the right number of turns, so you might need to use a rotary encoder but I don't  have any experience with them. However the H-bridge shield is pretty easy and there's even example code on the site I sent you earlier.

Maybe some push buttons so you can digitally talk to the Arduino. The Arduino can read the digital HIGH's and LOW's from the buttons and control the motor shield.

Hello, in my code I need to reset a char pointer array while the Arduino is running (ex. char id[50]; ), after I fill it with data.
I can't wait to reset it or relaunch it. I've tried the various methods listed below but none of them would work.

I tried memset

Code:

memset(id, '\0', 50);

but that didn't work.

I tried creating another char[]; and copying its blank contents into the original char

Code:

char idc[50];
char id[50]; //is filled with data
memcpy(id, idc, 50);

but that also didn't work.

I even tried the simple:

Code:

char idc[50];
char id[50]; //is filled with data

id = idc

But of course that wouldn't work (I was desperate).

So I must ask does anyone know how to reset a char pointer array while the Arduino is running without having to reset it?

Thanks, any help would be greatly appreciated!

Thank you so much to both of you. The solutions that you gave worked just fine and were very helpful!
Once again, Thank You so much!

Hello so I'm trying to convert a float to a char* to write to an SD card. Here's a simplified example. The problem is that it won't print the float to the SD card, instead it prints two question marks.

Code:

float new_money = 1.0;
char new_money_char[10];
File cust_file;

void setup(){
Serial.begin(9600);
sprintf(new_money_char, "%f", new_money);
cust_file = SD.open("file.txt", FILE_WRITE);
cust_file.write(new_money_char);
cust_file.close();
}


void loop(){
 
}

Any help would be appreciated, thank you!

Yeah, you'll need an H-Bridge to flip the motor direction. It's pretty easy actually and this shield can drive up to 2 amps per motor so you might want to give this one a shot.
https://www.sparkfun.com/products/9815

If you want it to spin a number of times and stop you should measure how long it takes to spin that number of times and put a delay for that long.

Thanks! However I don't understand what the "filename+filenameIndex" means in: strcpy(filename+filenameIndex, "filename.txt");

Hello, I need to dynamically change the directory or file name in the SD.open() [ex. SD.open("/0/file.txt") ] function. I tried String typecasting into the function but I get an error. I need to dynamically change which directory I'm opening based on an externally inputted variable while the Arduino is running in the wild. For example, if the number I get in the wild is 1,2,3 I would need a way to do this SD.open(1/2/3); without having to hard code the "1/2/3" argument in the function.
I tried typecasting the variables as a String, char, and char* but none of these worked and produced errors. If you know of a way to dynamically change the directory on the fly then that would be very much appreciated!
Thanks, here's my code.

Code:

#include <SD.h>
byte SD_CS = 4;
File test_file;
void setup(){
 Serial.begin(9600); //open serial port
 
 Serial.println("Initializing SD Card");
 pinMode(SD_CS, OUTPUT); //CS for SD card
 pinMode(10, OUTPUT); //CS must be an output for SPI to work
 
 if(!SD.begin(SD_CS)){
 Serial.println("SD card initialization failed");
 return;
 }
 
 Serial.println("SD card ready");
 
 test_file = SD.open(String(/0/test.txt), FILE_WRITE); //this line causes problems
}

void loop(){
 
}