Logger library enables you to use unified interface to send out or receive data using one function with different parameters. You leave buffer overflows to this library as it handles it all.

Logger library howto guide.

Below is a simple program that outlines the usage of the logger library, The whole function was head-written so there might be some errors, but it is more for a live representation of usage than anything else. If someone would write a nice example program feel free to link it here.

simple usage of logger library

#include "mbed.h"
#include "logger.h"
#include "errno.h"

Ticker printout;
/**
 * \def STASH_BUFFER_LEN
 * size of stash buffer that can be used to store logged data
 */
#define STASH_BUFFER_LEN 70000
/// stash_buffer size
static char stash_buffer[STASH_BUFFER_LEN];

/**
 * Log_pop_periodic is periodically printing the messages until the buffer is empty. 
 * Once the buffer is empty it detaches and waits for another command.
*/
void log_pop_periodic(void)
{
    if( log_pop(L_BTSERIAL,stash_buffer,STASH_BUFFER_LEN) == 1 )
    {
        printout.detach();
    }
}

static int i=0;
static char read_buffer[20];
/**
 * read data from BT serial
*/
void read_from_BT()
{

    if (BTSerial.readable()) {
        read_buffer[i++] = BTSerial.getc();
        // if we read the desired character
        if (read_buffer[i-1] == 'p')
        {
            // start the printout process which will log_pop logged data
            printout.attach(&log_pop_periodic,0.5);
        }
    }    
}

int main()
{
    log_init(L_SERIAL);
    log_init(L_BTSERIAL);
    BTSerial.attach(&read_from_BT);

    // while loop to fill in loads of stinky data
    while (1) {
            // read something, then stash it
            log_stash(L_INFO,print_buffer,strlen(print_buffer),stash_buffer,STASH_BUFFER_LEN);
    }
}
Committer:
Letme
Date:
Wed Dec 31 22:14:48 2014 +0000
Revision:
4:9360fdf3a818
Parent:
3:e1ed8ae7691e
Child:
5:f232b826e1f2
Library now does not define stashed buffer - it is up for user to define it. Also added some input parameter guarding since we are dealing with multiple pointers and we do not want to pass NULL around.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Letme 0:272c70e2366c 1 #ifndef _LOGGER_H_
Letme 0:272c70e2366c 2 #define _LOGGER_H_
Letme 0:272c70e2366c 3
Letme 2:9d04753a3ad2 4 /**
Letme 2:9d04753a3ad2 5 * Possible outputs of microcontroller
Letme 2:9d04753a3ad2 6 * @todo include also output to LCD display and some other displays
Letme 2:9d04753a3ad2 7 * \def L_SERIAL
Letme 2:9d04753a3ad2 8 * @ingroup logger_lib
Letme 2:9d04753a3ad2 9 * Output to Serial port
Letme 2:9d04753a3ad2 10 * \def L_FILE
Letme 2:9d04753a3ad2 11 * @ingroup logger_lib
Letme 2:9d04753a3ad2 12 * Output to file
Letme 2:9d04753a3ad2 13 * \def L_LED
Letme 2:9d04753a3ad2 14 * Output to LED (morse code;))
Letme 2:9d04753a3ad2 15 */
Letme 0:272c70e2366c 16 #define L_SERIAL 1
Letme 0:272c70e2366c 17 #define L_FILE 2
Letme 0:272c70e2366c 18 #define L_LED 3
Letme 3:e1ed8ae7691e 19 #define L_BTSERIAL 4
Letme 0:272c70e2366c 20
Letme 2:9d04753a3ad2 21 /**
Letme 2:9d04753a3ad2 22 * Error level indication
Letme 2:9d04753a3ad2 23 * @def L_CRIT_ERROR
Letme 2:9d04753a3ad2 24 * Critical error will append CE: to output
Letme 2:9d04753a3ad2 25 * @def L_ERROR
Letme 2:9d04753a3ad2 26 * Error will append E: to output
Letme 2:9d04753a3ad2 27 * @def L_WARNING
Letme 2:9d04753a3ad2 28 * Warning will append W: to output
Letme 2:9d04753a3ad2 29 * @def L_DEBUG
Letme 2:9d04753a3ad2 30 * Debug message will append D: to output
Letme 2:9d04753a3ad2 31 * @def L_INFO
Letme 2:9d04753a3ad2 32 * Information output will append I: to output
Letme 2:9d04753a3ad2 33 */
Letme 0:272c70e2366c 34 #define L_CRIT_ERROR 1
Letme 0:272c70e2366c 35 #define L_ERROR 2
Letme 0:272c70e2366c 36 #define L_WARNING 3
Letme 0:272c70e2366c 37 #define L_DEBUG 4
Letme 0:272c70e2366c 38 #define L_INFO 5
Letme 0:272c70e2366c 39
Letme 1:8837abc3f763 40 extern Serial logSerial;
Letme 3:e1ed8ae7691e 41 extern Serial BTSerial;
Letme 1:8837abc3f763 42
Letme 0:272c70e2366c 43 int32_t log_msg(uint8_t plc,uint8_t lvl, char *msg, uint32_t length);
Letme 0:272c70e2366c 44 int32_t log_init(uint8_t plc);
Letme 4:9360fdf3a818 45 int32_t log_stash(uint8_t lvl, char *msg, uint32_t length, char *stash_buffer,size_t stash_buffer_len);
Letme 4:9360fdf3a818 46 int32_t log_pop(uint8_t plc, char *stash_buffer,size_t stash_buffer_len);
Letme 0:272c70e2366c 47
Letme 0:272c70e2366c 48 #endif