Arduino Int To Byte Array

Processing byte reference. The ForceTronics blog provides tutorials on creating fun and unique electronic projects. I'm using an RC522 RFID reader with an Arduino UNO. On the performance side, since on any reasonable computer unsigned will have maximally 16 bytes (64 bits of 8 bytes is the case for all common architectures, except for probably some microcontrollers which will have less, even as less as 1 byte) (note that the upcoming RISCV architecture does have a native 16-byte (128-bit) integral data type. You can obtain a pointer to the array block in a Byte array by taking the address of the first element and assigning it to a pointer. It is free and easy to use. Re: Many values from Processing to Arduino Reply #1 - Aug 26 th , 2007, 3:20am I know this is old, but it's gone unanswered, you might have since found a solution, but others might be reading it looking for one. uidByte[i] that prints the bytes of the unique ID. Combine 2 bytes into int on an Arduino Recently I have been involved in a project using an iRobot Create. # re: How to convert a string to a byte array and convert a byte array to a string Thanks for a nice post! It has been a very effective approach which resulted to a profitable output for all who have been fortunate enough to come across. How to Use Arrays with Arduino Back in the old days, before medical information went digital – there were paper medical records. In this tutorial I’ll show how you can create your own LED Cube 3x3x3. Thank you, but what I need is to change an INT variable into BYTE, I need this to fill an array an send this array through serial port to my robot. ESP32 Arduino: Variable length arrays In this tutorial, we will check how to use variable length arrays on the Arduino core running on the ESP32. h library which is mfrc522. edit: I think I got off on a tangent here sorry. Arduino - Passing Arrays to Functions - To pass an array argument to a function, specify the name of the array without any brackets. to send out through another method Here is my code it is not working the way th. Well done sandeeprwt - I have used this in my code and it works brilliantly. In other languages, false is equivalent to 0 and true is equivalent to 1. read() tells the program to read a byte from the serial port myPort. Arrays of char variables work a little. jpg", convert it into byte array, and then reuse the converted byte array, and convert it back to a new BufferedImage, and save it back into a new name "new-darksouls. Corrections, suggestions, and new documentation should be posted to the Forum. Do three reads instead of one in the loop. Note: The Arduino serial ring buffer is 128 bytes or 64 registers. Arduino sends several bytes of data. Hi, need some help with converting variables into byte arrays for serial transmission on Arduino in each direction. Thank you, but what I need is to change an INT variable into BYTE, I need this to fill an array an send this array through serial port to my robot. the right most byte in the integer). The custom characters are usually 5pixels in width and 8 pixels in height, representing each box in the rows or columns of the LCD. After declaring the pins, we declare the byte arrays that describe the graphics to be displayed. CREATED BY THE UNITED STATES DEPART"}; unsigned int displayInt; int k; // counter variable char myChar; // read back a 2-byte int displayInt = pgm_read_word_near(charSet + k) // read back a char myChar = pgm_read_byte_near(signMessage + k); Arrays of strings. The Arduino block pairs the ATmega328 to your Edison via one of two UARTs. h library which is mfrc522. The range of the byte is from 127 to -128. ‣The array declaration causes the. All Forums. // Pin connected to SER of 74HC595 int DATA = 10; byte // We will store the bytes sent from the computer // into this array: byte. In our case, it’s connected to digital pin#5. > I think you can remove all string. Instead the bytes "1" then "2" then "3" are sent. Por brevedad el array del ejemplo está definido pero vacío. This example seems to work, but not when I send a negative integer. I'm just not sure how to do this. The byte array represents which pixels of the box to be turned on or off. for the two byte array [255 178] (lower byte. Lengt Stack Exchange Network. Hi all, I need to convert to a long inetger value to byte array in c so that i can access the four byte value of long integer separately. Hi All, I want to change HEX String to Byte Array, but I can't get the expected result. In fact, it can be done in a single line. The int size varies from board to board. Corrections, suggestions, and new documentation should be posted to the Forum. A string can be converted into a byte array. Although this shows the flexibility Elixir provides for working with bits and bytes, 99% of the time you will be working with binaries and using the is_binary/1 and byte_size/1 functions. The software for a DCC accessory decoder is remarkably simple. Convert bool, int. I use this code constantly. ive got a pointer to an array of bytes, but i want to read 4 of those bytes as an integer. bitRead(x, n) - Reads a bit of a number. Hi all, I need to convert to a long inetger value to byte array in c so that i can access the four byte value of long integer separately. Find anything that can be improved? Suggest corrections and new documentation via GitHub. Arrays allow you do to more than just hold the pin numbers though. However how do we convert a Byte[] array to String afterward? Simple toString() function like following code is not working property. Thanks for helping. The sender code changes characters into bytes and, if necessary, it changes number values into characters before turning it into bytes. The first function takes in an array of up to 8 integers valued 1 or -1 and generates a corresponding byte; the second does the reverse. •That is, pointers are similar to uninitialized array variables. To me this meant storing a four byte long in four bytes. If you are using a char array and a byte array then you can just run a loop that will change one to the other. The Windows Remote Arduino Experience app is where you can adjust the LED status like the Serial Monitor. Unfortunately, these functions only allow accessing one byte at a time. I have following problem: I'm reading 8 bit signal from one Arduino pin and store all informatin in bool array. The size of the char datatype is at least 8 bits. Arduino Reset Button-- This reset button is tied to the Arduino's reset line. buf: the buffer to copy the characters into (byte []) len: the size of the buffer (unsigned int) Returns. What you want to do (calculating the number of elements in the array) is to divide the number of bytes in the array by the number of bytes for one. Matlab inherently uses 64 bit (double) numbers for everything, so keep that in mind when you try to reassemble the bytes on the Arduino end. How can I do this. int can also store negative numbers using complement math. Charlists A charlist is nothing more than a list of code points. On Arduino, char is int8_t but byte is uint8_t. Could anyone please suggest me a way of doing this. A Library to Ease Accessing Flash-based (PROGMEM) Data. Note: All LEDs need a current limiting resistor placed on either the anode side or cathode side to prevent the LED from burning out. Hi all, I need to convert to a long inetger value to byte array in c so that i can access the four byte value of long integer separately. However, this method is not very good because of the low PWM frequency of the XBee and the need to filter signals introducing additional phase delays on top of transmission times. This is the standard. El código es bastante sencillo. To me this meant storing a four byte long in four bytes. I'm using an RC522 RFID reader with an Arduino UNO. How to: Convert a byte Array to an int (C# Programming Guide) 07/20/2015; 2 minutes to read +6; In this article. The following Processing code shows the problem when using a data packet array of the byte data type. My question is,how can I convert bytes values into integer. Again, this is because using data types which require more than 8 bits of storage (like int, long, or float also requires the compiler to generate more actual machine code for the addition to be realized - the processor itself simply doesn't have. When applied to a class type, the result is the size of an object of that class plus any additional padding required to place such object in an array. ) Record the value: _____ (Note: This address should be in program memory. An element in an array refers to each value in the array. For example, an array of 7 values has index values between 0 and 6. Arduino Reset Button-- This reset button is tied to the Arduino's reset line. Learn more about arduino, serial is there any way you could make a 1000x3 array just containing bytes 12,20 & 21. 4 bytes for variables __brkval and __flp (used in memdebug) 2 bytes pushed onto the stack in main (to save registers) 2 bytes pushed onto the stack in setup (to save registers) 4 bytes pushed onto the stack in getFreeMemory (to save registers) 1 byte because the stack pointer starts at 0x8FF rather than 0x900 (That's 346 bytes accounted for). Find anything that can be improved? Suggest corrections and new documentation via GitHub. Java unknown input byte length convertTo int stack overflow enter image description here. All Forums. The OpenMV is defined as a SLAVE:. It is found in the abstract base class for all array types. Arduino language code to digitize an acoustic accordion. The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3. The system works poorly: The buffers files are saved way too slowly! It feels like there is a bottleneck somewhere. A bool can be converted to 0 or 1. Surprisingly, this question pops up often. These were packets of information about when you were born, any conditions you have had, and maybe a picture of the tapeworm they pulled out of your belly in high school. Then another for-statement to build an char array with the hex presentation of each string. The code snippet in this article converts different integer values to a byte array and vice-versa using BitConverter class. And “char” is just an 8-bit integer. •An array variable is similar to a pointer of that type that has been initialized to the address of the first entry of the block. If you continue browsing the site, you agree to the use of cookies on this website. How To Make An Arduino-powered LED Matrix Conway’s Game Of Life – DIY While byte arrays would be much more. double On the Uno and other ATMEGA based boards, Double precision floating-point number occupies four bytes. NET Framework is provides functionality to convert base data types to an array of bytes, and an array of bytes to base data types. Requests can be submitted to the API using either GET or POST, and the returned result can be in either JSON (default), JSONP or serialised PHP. I've been trying to send a long integer from an Arduino to my C++ program via the serial port. The receiver will then receive the byte array from the other Arduino and interpret it there. void readAndReportData (byte address, int theRegister, byte numBytes, byte stopTX) // allow I2C requests that don't require a register read // for example, some devices using an interrupt pin to signify new data available. Utility functions for converting values between hex strings and decimal numbers on Arduino. Convert bool, int. I thought about a for-statement to store every single letter in a string array. More than 1 year has passed since last update. Internally, it’s represented as an array of characters. using System; public class Example { public static void Main() { // Create an Integer from a 4-byte array. You can use these arrays with programs for embedded systems with microcontrollers to output graphics on monochromatic LCD's or thermal printers (like Arduino with the Adafruit mini printer, which I needed this for). A char array is a byte arrray. Arrays are ``second-class citizens'' in C. Array subscripts must be of integer type. I friend also had the problem recently so I figured maybe it was common enough that this post could help other people. Scribd is the world's largest social reading and publishing site. Strings are stored with two bytes per character. Example 2: String to Integer conversion Arduino String val = “1234”; int result = val. Converting ASCII to Integer in your Arduino or other C code (specifically in a VirtuabotixPacket) September 1, 2013 Joseph Dattilo Migrated to a new server, adding chat to all of my sites, and some other tidbits. The reason i am posting this short post is because just recently i realized that m. ive got a pointer to an array of bytes, but i want to read 4 of those bytes as an integer. Reference Home. GetBytes() to convert a string to Byte array. Internally, it’s represented as an array of characters. I2C normally only sends a single byte at a time so you are limited to 255 as the largest number. Corrections, suggestions, and new documentation should be posted to the Forum. My question is,how can I convert bytes values into integer. Below is the code for the receiver. Related Posts: byteSlice() Implementing the Perceptron Rule; Arduino: A new & improved Button library with some handy features. A char array is a byte arrray. Convert numeric variable for eg. It basically packages serial data for strtok_r to split into pieces paced on predefined deliminators. How Arduino Reads Temperature. How to Write Binary and Hexadecimal Numbers in Arduino For an introduction to binary and hexadecimal notation, read this post. The only data this program has to send is the asterisk character, for when it wants to receive a random number from the Arduino. The sketch below shows the basic use of an array. The left-side value can be. Well done sandeeprwt - I have used this in my code and it works brilliantly. Byte Byte speichert einen 8-Bit numerischen, ganzzahligen Wert ohne Dezimalkomma. I guess that byte array contains text in a certain character encoding, and you want to make characters out of it. Arduino - Cast Int to Byte - What happens? For a project I need to spread a 16-bit unsigned integer across one byte variable and two 1-bit variables, all of which will be written to pins. Org under C. I just need to change Type and send it on serial port. In other languages, false is equivalent to 0 and true is equivalent to 1. - benrugg/Arduino-Hex-Decimal-Conversion. I need to convert a float to 4 bytes so it can be sent on a 8 bit data channel. A word is 2 bytes (except on Due, Zero and similar boards where it is 4 bytes), which already gets you a huge range of 65536 (256 2). For example, Arduino defines an int as two bytes, but Processing (Java) defines an int as four bytes (short is the Java type for a 16-bit integer). I read a file using char[] and I want to convert specific bytes to integer. Corrections, suggestions, and new documentation should be posted to the Forum. Here's an example: link = self. I'm waiting for your help. Every time you read a byte, it’s removed from the serial buffer. Find anything that can be improved? Suggest corrections and new documentation via GitHub. The delay between displaying each number allows us to see clearly how the change made to display the next number in the sequence. The Wii nunchuck has 6 pins, but we only need to use four of them. Buffer is where the data is stored, set offset = 0 to start at the beginning, count is the number of bytes to read, returnValue is the number of bytes read. Could anyone please suggest me a way of doing this. Michael's solution converts the byte values to numeric strings. El emisor recorre el array, y emplea una función para enviar los bytes que forman cada uno de los datos. No difference whatsoever. What you want to do (calculating the number of elements in the array) is to divide the number of bytes in the array by the number of bytes for one. I am getting good stable data from the first arm in my processing sketch, breaking it into bytes in processing, sending those bytes to the second arm from processing, reassembling them to integer values on the arduino UNO, and echoing the integer values back to a processing sketch. For example: i have INT A=0, I need to send this as a Byte 0x00 in serial port INT A=255 , send as Byte 0xFF. ASCIIEncoding. ftoa() – convert a floating point number to a character array on the Arduino December 7, 2016 1 Comment Written by Paul Converting floating point numbers to zero-terminated character strings is not natively supported for the Arduino. A few of these include: I2C or Serial Sensors – There are advanced sensor modules that often can measure barometric pressure, temperature, humidity, and other conditions all in one package. > There is a method, found below, ho to handle strings. (For example, byte(128) evaluates to -128. I use this code constantly. docx - Free download as Word Doc (. Below is an example that converts a string into a byte array. However, you will also learn that the flash program memory is much larger and can easily handle an array of the size. There seems to be many examples of this when i search, but I've not had much luck except for one example. This is an IoT based project in which we will user GPRS, present on the GSM Module SIM900A board, to send some data to the web service on the internet. This example shows you how to use the BitConverter class to convert an array of bytes to an int and back to an array of bytes. IsLittleEndian to see which way around that is going to appear!. (You will need to write a loop using one of the above macros to read the char value of each entry in the array before printing it. If i was sending a number from 0 to 255 it would be easy, I would just send 0x00 - 0xFF, but what if I want to send a number longer than one byte, say 23,582? How would I convert 23,582 into bytes that I could send one at a time. To run this project, simply follow the wiring diagram, and then run the code in your Arduino IDE. I am a newbie yet. Converting Float to String and Character Array in a Few Simple Steps - Arduino: Do you want to convert an floating point value to a string? If that is so, then there are two methods that i found really helpful. How to Write Binary and Hexadecimal Numbers in Arduino For an introduction to binary and hexadecimal notation, read this post. El emisor recorre el array, y emplea una función para enviar los bytes que forman cada uno de los datos. The left-side value can be. The Arduino can't load the byte until the Raspi completes the current one-byte transmission, but the Arduino must have loaded the byte before the Raspi begins sending the next byte. Arduino: LED Matrix state as array of bytes Recently I released and have written about Arduino: LED Matrix Editor This is online editor for LED dot matrices, that helps people to make animations and save them as C-code for Arduino. I am establishing a serial connection with my Arduino. When I think of Zen I think of how the organization of the outside world can effect the way I think and feel - I am sure this is way off - but that's all I have cared to ponder it thus far. array attempt[], and when the user presses #, the function checkPin() is called. Joystick Library API. The LCD display shows the operating band, the. Btw, is the LED thing only to show activity? Is your real goal to store and send bytes back and forth?. The BitConverter class has a static overloaded GetBytes method that takes an integer, double, bool, short, long, or other base type value and convert that to a array of bytes. This is why I wrote the EEPROMex library, an extension of the standard Arduino EEPROM library. Arduino language code to digitize an acoustic accordion. If you are using a char, unsigned char, or byte array there is a way to accomplish the copy without knowing the length of the data. You might ask how would you know the length of a string you are reading, for this I would save the length of a string also to the EEPROM in a set location then read that location first before reading the string its self. Well done sandeeprwt - I have used this in my code and it works brilliantly. The example also shows how you can explicitly get the pointer of any array element. Note that this code is intended for a Mega since it will interpret the data received from the other Arduino and then print to the Serial Monitor what it received so that the user can check it. Carrying on from 2 is the problem of endianness. The char type holds a single byte value. Arduino - Arrays - An array is a consecutive group of memory locations that are of the same type. Once I wrote some code to send the the results back to processing and print them in the processing serial monitor the correct results were displayed. In the first example for nRF24L01 arduino interfacing, we are going to simply send the data from one Arduino to other Arduino. The modbus_update() method updates the holdingRegs register array and checks communication. Using Arrays. All Forums. Converting to a C++ String object is another story. Do not change this pin or your DCC decoder won’t work. The result is the number of elements in the array. Return the contents of bytearray as a char array after checking for a NULL pointer. I friend also had the problem recently so I figured maybe it was common enough that this post could help other people. Contrary to popular belief, this is not a pointer to the array, and the array has implicitly been cast to a pointer, which is commonly referred to as decayed pointer, as it has been stripped of the information an array type provides. I just modify the code I found on the Internet, not from this post, so the boolean array can’t control LEDs light in different color, right? how to create the LED array with arduino (sorry I am just a newbie with arduino)? Can I send my sample code to you and help me find out if this is possible? (I use ws2812b strip and esp8266 with my. Arduino page erwans blog here below the sketch note that we use two arrays and go up down in each array. Hi, The sketches pasted below send 70 numbers from processing to arduino. Because both the power supply and the Arduino both use TTL for communication, you don't need the converter [4]. To refer to a particular location or element in the array, we specify the name of. So it’s good practice to read the byte into a variable as shown above, then never read again until you want another byte. Actually I want to write a function. int red, green, blue string color red = 128 green = 255 blue = 0 The HEX values would be: red = 80 green = FF blue = 00 I need my end 'color' variable to equal "0x80FF00" so I can send this color data to my LEDs. This memory is non-volatile, which means that the data doesn't get erased when the board loses power. The subscript itself can be any legitimate C expression that yields an integer value, even a general expression. GetBytes() method to convert an integer to a byte array of size 4. You need to declare a char array to hold the GPS data which you probably already have, and then a string array, in this case msg_field[] with enough elements for each field in the char array - a field being the data between the commas. You can look at the EEPROM on Arduino as an array where each element is one byte. •That is, pointers are similar to uninitialized array variables. storing arduino serial data to cell array. Most of the time you will connect the arduino to a master via serial using a MAX485 or similar. The Arduino library has a sizeof function that can help with this. In fact, it can be done in a single line. The Arduino Reference text is licensed under a Creative Commons Attribution-Share Alike 3. If you want to transmit the byte array for a 32 bit number, use the single() command, as in fprintf('%d\n',typecast(single(1. There are several ways to read temperature with an Arduino. How Arduino Reads Temperature. If you want to learn about them, drive one using an Arduino, or build them, this is the place to start. lowByte(x) - Extracts the low-order (rightmost) byte of a variable (e. These include how you declare the array, the hardware memory limits, and any restrictions imposed by the compiler. char array[9] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00}; from there on my sketch processes this array. Here, int has the range of -32,768 to 32,767. I have some code below that is supposed to be converting a C (Arduino) 8-bit byte array to a 16-bit int array, but it only seems to partially work. An optional second parameter specifies the base (format) to use; permitted values are BYTE, BIN (binary, or base 2), OCT (octal, or base 8), DEC (decimal, or base 10), HEX (hexadecimal, or base 16). This code makes use of the displayBinary procedure we wrote to count upwards in binary. Arduino Code Request - Byte Stream to Array looked into exactly how the Arduino serial library works I'll leave the code here since the concept of how it checks. That's the way to do it, but remember that different computer architectures have different ways to represent integer values in memory, so don't assume that if you put the same four bytes together in the same order in a different device that they will represent the same unsigned long value. docx), PDF File (. Tip: Here we find that a byte array is a precise representation of bytes, not a higher-level. uidByte[i] that prints the bytes of the unique ID. In order to get data from it I have to send data in the form of byte arrays. That is, the double implementation is exactly the same as the float, with no gain in precision. toCharArray() Reference Home. Converting Float to String and Character Array in a Few Simple Steps - Arduino: Do you want to convert an floating point value to a string? If that is so, then there are two methods that i found really helpful. This example shows you how to use the BitConverter class to convert an array of bytes to an int and back to an array of bytes. I am getting good stable data from the first arm in my processing sketch, breaking it into bytes in processing, sending those bytes to the second arm from processing, reassembling them to integer values on the arduino UNO, and echoing the integer values back to a processing sketch. Joystick Library API. I am sending variables from my arduino and want to set the variables in processing from these. The sender code changes characters into bytes and, if necessary, it changes number values into characters before turning it into bytes. In Python 2, this is the same as str. Requests can be submitted to the API using either GET or POST, and the returned result can be in either JSON (default), JSONP or serialised PHP. Find anything that can be improved? Suggest corrections and new documentation via GitHub. Next, we create a set of variables which comprises of byte arrays that represent custom characters to be created and displayed. h library which is mfrc522. This is the spot we want to change or look at in the array. If you google “Arduino memory” you will quickly learn that the RAM memory size is too small for a 3000 element array of anything. Arrays •Arrays are blocks of consecutive types. The function sizeof() returns the number of bytes in a variable, not the number of elements. Integer Ein Integer oder auch INT genannt ist die am meisten benutzte Variante um Ganzzahlen ohne Dezimalkomma zu Speichern. GetBytes() method to convert an integer to a byte array of size 4. A string variable needs to be defined to save the converted integer. 11/04/2016; 2 minutes to read +1; In this article. Firmata is already include in your Arduino IDE. The iteration method works but it is waste of energy so here is the code you need. The first function takes in an array of up to 8 integers valued 1 or -1 and generates a corresponding byte; the second does the reverse. For example, an array of 7 values has index values between 0 and 6. I will remove the ambiguity in the next version. I am getting good stable data from the first arm in my processing sketch, breaking it into bytes in processing, sending those bytes to the second arm from processing, reassembling them to integer values on the arduino UNO, and echoing the integer values back to a processing sketch. Edit, it is not a string value but a 32 unsigned integer. Now that we know everything about the module, we can begin hooking it up to our Arduino! To start with, connect VCC pin on the module to 3. Converting to a C++ String object is another story. > Arduino ATMega168 can handle strings with 613 characters, over serial. Note that when declaring an array of type char, one more element than your initialization is required, to hold the required null character. //used to hold an int that is the color red //used to hold an int that is the color green //used to hold an int that is the color blue //convert the string to a char array //let's pars the array at each comma //let's pars the array at each comma //let's pars the array at each comma //we now print each value we parsed separately //this is the. Converting Integer to Character Arduino: Converting an integer to character is an easy process. Thanks Paul [ps1]. The data is coming from a gyroscope so the data is always changing. How to Use Arrays with Arduino Back in the old days, before medical information went digital - there were paper medical records. Bytes are read like peas coming out of a peashooter. After knowing primitive data types and Java rules of Data Type Casting (Type Conversion), let us cast int to byte. println("Hello World"); the text "Hello World" ends up being stored in ram, not in flash, and uses 11 bytes. ASCIIEncoding. int can also store negative numbers using complement math. This type of array allocation, where the size of the array is determined at compile-time, is called static allocation. That is done with the == symbol instead. Converting Float to String and Character Array in a Few Simple Steps - Arduino: Do you want to convert an floating point value to a string? If that is so, then there are two methods that i found really helpful. // Pin connected to SER of 74HC595 int DATA = 10; byte // We will store the bytes sent from the computer // into this array: byte. Der Wert kann zwischen 0 und 255 liegen. Q&A for Work. The sketch below shows the basic use of an array. int PyByteArray_Resize (PyObject *bytearray, Py_ssize_t len) ¶ Resize the internal buffer of bytearray to len. I found this code that does it backwards (16bit int to two 8-bit bytes), but I can't figure out how to do it the other way around. Convert bool, int. The following figure illustrates a two-dimensional array, a. i'm having a lot of trouble with this. This is all set for the Arduino UNO R3. BigEndianUnicode", which is not. At , the values of keys pressed are compared against the PIN stored in the array PIN[] at , which holds the secret number. This keyword does not return a count of elements, rather the number of bytes the array occupies in memory. print(78, BYTE) gives "N". Introduction to the Arduino Microcontroller. For example, if an array hourlyTemperatures has been declared as th. En el ejemplo, vamos a enviar un array de int. GetBytes() method to convert an integer to a byte array of size 4. The int data type is a word and Arduino comes with highByte() and lowByte() to extract the left and right byte from a word. If you do actually need to send plain text representation of hex (which I would bet you do not need to do) here is a hint:. write(1200) --> Processing creates a circular buffer with byte (array of bytes) --> Processing save the array into text file --> text file analysed by Matlab. Once I wrote some code to send the the results back to processing and print them in the processing serial monitor the correct results were displayed. When you are using this library, you need to consider variable byte size, because if you are using different platforms, then there may be some errors, because int on platform 1 has 4 bytes and int on platform 2 may has 2 bytes. C / C++ Forums on Bytes. GetBytes() to convert a string to Byte array. 5678 but when i do an atof. toInt (); //Converts string to integer.