File content as of revision 14:3f4098e94c29:

#include "RN52.h"
#include "mbed.h"

// RN52 action command definitions
#define PLAYPAUSE       "AP\r"
#define NEXTTRACK       "AT+\r"
#define PREVTRACK       "AT-\r"
#define CONNECT         "B\r"
#define DISCONNECT      "@,1\r"
#define REBOOT          "R,1\r"
#define VOLUMEUP        "AV+\r"
#define MAXVOLUME       "SS,0F\r"
#define GETSTATUS       "Q\r"
#define ASSISTANT       "P\r"
#define CALLER_ID       "T\r"
#define TRACK_METADATA  "AD\r"

#define RESPONSE_TIMEOUT    30 //ms

Serial serial(p13, p14);  // tx, rx
DigitalIn event_pin(p20);
DigitalOut enable_pin(p5);
Timer responsetime;
char temp_response[255];


void RN52::init(){
    enable();
    serial.baud(115200);
    printf("Serial baudrate set\r\n");
    
    //make sure event pin is pulled low
    if(event_pin == 0) {
        serial.printf(GETSTATUS);
        capture_response(temp_response);
    }
}

void RN52::enable(){
    enable_pin = 1;
}

void RN52::disable(){
    enable_pin = 0;
    serial.printf(REBOOT);
    capture_response(temp_response);
}

bool RN52::check_event(RN52_RESULT * result){
    clear_serial();
    if(event_pin == 0) {
        clear_result(result);
        get_status(result);
        switch (result->event) {
            case RN52_CALLER_ID_EVENT:
                get_caller_id(result);
                break;
            case RN52_TRACK_CHANGE_EVENT:
                get_track_metadata(result);
                break;
        }
        return 1;   
    }
    return 0;
}

bool RN52::connect(){
    serial.printf(CONNECT);
    return capture_response(temp_response);
}

bool RN52::disconnect(){
    serial.printf(DISCONNECT);
    return capture_response(temp_response);
}

bool RN52::next_track(){
    serial.printf(NEXTTRACK);
    return capture_response(temp_response);
}

bool RN52::prev_track(){
    serial.printf(PREVTRACK);
    return capture_response(temp_response);
}

bool RN52::toggle_play(){
    serial.printf(PLAYPAUSE);
    return capture_response(temp_response);
}

bool RN52::maxvolume(){
    serial.printf(MAXVOLUME);
    return capture_response(temp_response);
}

bool RN52::get_status(RN52_RESULT * result){
    serial.printf(GETSTATUS);
    capture_response(result->response);
    int response_value = strtoul(result->response, NULL, 16);
    result->media_connected = (response_value & (1 << 10)) >> 10; //byte 0, bit 2
    result->phone_connected = (response_value & (1 << 11)) >> 11; //byte 0, bit 3
    result->connection = (RN52_CONNECTION)(response_value & 0x0F); //byte 1, bits 0-3
    switch (response_value & 0x3000) {
        case 0x1000:  //byte 0, bit 4
            result->event = RN52_CALLER_ID_EVENT;
            break;
        case 0x2000:  //byte 0, bit 5
            result->event = RN52_TRACK_CHANGE_EVENT;
            break;
        default:
            result->event = RN52_OTHER_EVENT;
            break;
    }
    return 1;
}

bool RN52::get_caller_id(RN52_RESULT * result){
    serial.printf(CALLER_ID);
    capture_response(result->response);
    //parse the response
    return 1;
}


bool RN52::get_track_metadata(RN52_RESULT * result){
    serial.printf(TRACK_METADATA);
    if(capture_response(result->response)) {//AOK
        while(result->response[3] != 'e') { //time(ms) - always the last one
            capture_response(result->response);
            switch (result->response[3]) {
                case 'l': //Title
                    copy_response(result->response, result->title, 6);
                    break;
                case 'i': //Artist
                    copy_response(result->response, result->artist, 7);
                    break; 
                case 'u': //Album
                    copy_response(result->response, result->album, 6);
                    break; 
                case 'r': //Genre
                    copy_response(result->response, result->genre, 6);
                    break;
                case 'c': //TrackNumber or TrackCount
                    {
                        char number_string[5];
                        if(result->response[5] == 'N') { //TrackNumber
                            copy_response(result->response, number_string, 12);
                            result->track_number = strtoul(number_string, NULL, 10);
                        }
                        else { //TrackCount
                            copy_response(result->response, number_string, 11);
                            result->track_count = strtoul(number_string, NULL, 10);
                        }
                    }
                    break;
                case 'e': //time(ms) - always the last one
                    {
                        char duration_string[10];                                    
                        copy_response(result->response, duration_string, 9);
                        result->duration = strtoul(duration_string, NULL, 10);
                    }
                    break;                                   
            }
        }
        clear_serial();
    }
    return 1;
}

bool RN52::capture_response(char * str){        
    responsetime.reset();
    responsetime.start();
    char c = ' ';
    char n = 0;
    while(c != '\n') {
        if(serial.readable()) {
            c = serial.getc();
            str[n] = c;
            n++;
        }   
        else if(responsetime.read_ms() > RESPONSE_TIMEOUT) {
            clear_serial();
            printf("timeout occured\r\n last response: %s\r\n", str);
            return 0;
        }
    }
    str[n-2] = '\0'; //terminate string before \r\n
    return (str[0] == 'A');
}

void RN52::clear_serial(){
    while(serial.readable()) {
        serial.getc();
    }
}

void RN52::copy_response(char * source, char * destination, char offset){        
    int n = 0;
    while(source[n+offset+1] != '\0') { //remove carraige return in the end
        destination[n] = source[n+offset]; 
        n++;
    }
    destination[n] = '\0'; //end string where carriage was
}

void RN52::clear_result(RN52_RESULT * result) {
    result->event = RN52_NO_EVENT;
    result->media_connected = 0;
    result->phone_connected = 0;
    result->connection = RN52_NOT_SET;
    result->title[0] = '\0';
    result->artist[0] = '\0';
    result->album[0] = '\0';
    result->genre[0] = '\0';
    result->duration = 0;
    result->track_number = 1;
    result->track_count = 1;
    result->response[0] = '\0'; 
}