======unsigned int ======
On the Uno and other ATMEGA based boards, unsigned ints (unsigned integers) are the same as ints in that they store a 2 byte value. Instead of storing nega... 4,294,967,295 (2^32 - 1).
The difference between unsigned ints and (signed) ints, lies in the way the highe... 's complement math.]]
[=unsigned int ledPin = 13;=]
iki library source code example reference}}
===== unsigned =====
unsigned char ch;
unsigned long int l;
unsigned char 0 to 255
unsigned int 0 to 65535
[or 0 to 4294967295 if '-mnoshort' is set]
unsigned short int 0 to 65535
unsigned long int 0 to
======unsigned long ======
Unsigned long variables are extended size variables fo... nd store 32 bits (4 bytes). Unlike standard longs unsigned longs won't store negative numbers, making their ... 5 (2^32 - 1).
unsigned long time;
[=unsigned long var = val;=]
*var - your long variable name
ed char (1 byte) -127 to 128
prog_uchar - an unsigned char (1 byte) 0 to 255
prog_int16_t - a signed... (2 bytes) -32,767 to 32,768
prog_uint16_t - an unsigned int (2 bytes) 0 to 65,535
prog_int32_t - a sig... ,483,648 to * 2,147,483,647.
prog_uint32_t - an unsigned long (4 bytes) 0 to 4,294,967,295
==== Example ... g code fragments illustrate how to read and write unsigned chars (bytes) and ints (2 bytes) to PROGMEM.
optional length modifier:\\
h short or unsigned short\\
l long or unsigned long\\
L long double... decimal notation\\
o int argument, printed in unsigned octal notation\\
x,X int argument, printed in unsigned hexadecimal notation\\
u int argument, printed in unsigned decimal notation\\
unsigned long int strtoul(const char *str, char **endptr, ... base);
strtoul Converting a string to an unsigned long integer\\
str: the string to be converted\\
... d )
char string ="20405";
unsigned long int number;
number = strtoul(string, &end... 10);
printf("string is %s\n",string);
printf("unsigned long int is %li\n", number);
======unsigned char ======
An unsigned data type that occupies 1 byte of memory. ... as the [[arduino:data types:Byte]] datatype.
The unsigned char datatype encodes numbers from 0 to 255.
Fo... pe is to be preferred.
[=unsigned char myChar = 240;=]
====See also ====
======Integer Constants ======
Integer constants are numbers used directly in a sketch, like //123//. By default, these numbers are treated as [[arduino:data_types:int|int]]'s but you can change this with the U and L modifiers (see below).
Normally, integer constants are treated as base 10 (decimal) integers, but special notation (formatters) may be used to enter numbers in other bases.
Base Example Formatter Comment
10 (decimal) 123 none
2 (binary) B1111011 leading 'B' only works with 8 bit values (0 to 255)
characters 0-1 valid
8 (octal) 0173 leading "0" characters 0-7 valid
16 (hexadecimal) 0x7B leading "0x" characters 0-9, A-F, a-f valid
**Decimal** is base 10. This is the common-sense math with which you are acquainted. Constants without other prefixes are assumed to be in decimal format.
101 // same as 101 decimal ((1 * 10^2) + (0 * 10^1) + 1)
**Binary** is base two. Only characters 0 and 1 are valid.
B101 // same as 5 decimal ((1 * 2^2) + (0 * 2^1) + 1)
The binary formatter only works on bytes (8 bits) between 0 (B0) and 255 (B11111111). If it is convenient to input an int (16 bits) in binary form you can do it a two-step procedure such as:
myInt = (B11001100 * 256) + B10101010; // B11001100 is the high byte
**Octal** is base eight. Only characters 0 through 7 are valid. Octal values are indicated by the prefix "0"
0101 // same as 65 decimal ((1 * 8^2) + (0 * 8^1) + 1) </code>
->It is possible to generate a hard-to-find bug by (unintentionally) including a leading zero before a constant and having the compiler unintentionally interpret your constant as octal.
**Hexadecimal (or hex)** is base sixteen. Valid characters are 0 through 9 and letters A through F; A has the value 10, B is 11, up to F, which is 15. Hex values are indicated by the prefix "0x". Note that A-F may be syted in upper or lower case (a-f).
0x101 // same as 257 decimal ((1 * 16^2) + (0 * 16^1) + 1)
==== U & L formatters ====
By default, an integer constant is treated as an [[arduino:data_types:int|int]] with the attendant limitations in values. To specify an integer constant with another data type, follow it with:
* a 'u' or 'U' to force the constant into an unsigned data format. Example: //33u//
* a 'l' or 'L' to force the constant into a long data format. Example: //100000L//
* a 'ul' or 'UL' to force the constant into an unsigned long constant. Example: //32767ul//
====See also ====
* [[arduino:data_types:unsignedint| unsigned int]]
* [[UnsignedLong | unsigned long]]