Embedded version of the famous "printf( )" function.

This code is based in the code shared in this link: http://e2e.ti.com/support/development_tools/code_composer_studio/f/81/p/30479/107146

The idea is create an simple and efficient library to meet some common needs in embedded systems, as:

• convert numbers to strings
• send strings over serial port
• convert a string into number

To maintain the ballance between code size, speed and functionalities it's possible to do little changes in the code using C preprocessor.

• enable padding
• enable float number
• increase precision (using double)
• enable extra decimal places
• enable binary notation

All of this commenting/uncommenting the preprocessors.

The famous "printf( )" functions is named as "embedded_printf( )" and use a similar sintax as the original function with some reductions.

Besides the "embedded_printf( )" there are a simple version of each principal function. This can be useful when the traditional sintax is not required or when the speed of code/size is more important.

To facilitate the portability the code is modular and the configuration of the serial port is done in separate files ("serial_conf.h" and "serial_conf.c").

If possible contribute sending bug repports, new functions or porting the library to new devices.

MSP430

MSP430G2553 (launchpad valueline), MSP430FR6989 (Launchpad EXP430FR6989)

More MSP430's, MSP432, Stellaris/Tiva

// similar to the "printf( )"
int embedded_printf(char *format, ...);

// Print a String in the serial port
int embedded_prints(char *string, unsigned int width, unsigned int pad);

// Convert an integer number (signed or unsigned) with max size of 32bits (long) to array
int embedded_ltoa(char *print_buf, signed long input, unsigned int base, unsigned int sg, unsigned int width, unsigned int pad, unsigned char letbase);

// convert convert a float number to array - two versions defined by the preprocessors
int embedded_ftoa(char *print_buf, double input, signed int dp, unsigned int sci);
int embedded_ftoa(char *print_buf, float input, signed int dp, unsigned int sci);

// simple function to print a String
unsigned int print_string(char *string);

// simple function to print a signed long
unsigned int print_long(long number);

// simple function to print a unsigned long
unsigned int print_ulong(unsigned long number);

// simple function to print a hexadecimal;
unsigned int print_hexa(long number);

// simple function to print a binary
unsigned int print_binary(long number, unsigned int bits);

// simple function to print a float/double  - two versions defined by the preprocessors
unsigned int print_float(double number, int dp);
unsigned int print_float(float number, int dp);

// simple function to print in scientific notatio - two versions defined by the preprocessors
unsigned int print_scientific(double number, int dp);
unsigned int print_scientific(float number, int dp);

// convert string to float number - two versions defined by the preprocessors
void embedded_string2number(unsigned char *string, double *number);
void embedded_string2number(unsigned char *string, float *number);

// Call the specific function to send data
void putChar(unsigned char byte);

// return n lines in the terminal
void linesUp(unsigned char lines);

To evaluate the performance I compared the time taken to perform the "Embedded_printf" functions with the "printf" function native in the compiler Code Composer Studio. (More tips how do this in this website: http://processors.wiki.ti.com/index.php/Printf_support_for_MSP430_CCSTUDIO_compiler). The test was performed using the Launchpad EXP430FR6989.

• CCS native

• RAM: 368 bytes - FRAM: 160 bytes - FRAM2: 1574 bytes - time(ms): 36.09

• Embedded_Printf

• RAM: 160 bytes - FRAM: 72 bytes - FRAM2: 1238 bytes - time(ms): 36.05

• Embedded_Printf (different style)

• RAM: 160 bytes - FRAM: 60 bytes - FRAM2: 800 bytes - time(ms): 36.07

• CCS native

• RAM: 682 bytes - FRAM: 512 bytes - FRAM2: 15348 bytes - time(ms): 75.6

• Embedded_Printf

• RAM: 160 bytes - FRAM: 98 bytes - FRAM2: 3368 bytes - time(ms): 70.4

• Embedded_Printf (different style)

• RAM: 160 bytes - FRAM: 74 bytes - FRAM2: 2664 bytes - time(ms): 70.4

• enable to configure library inside the main.c (or similar)

This software is provided 'as is' with no explicit or implied warranties in respect of its properties, including, but not limited to, correctness and/or fitness for purpose.