cmd_io.cpp

00001 //
00002 // cmd_io.cpp : library of routines to communicate with virtual COM port
00003 // ==========
00004 //
00005 #include    "mbed.h"
00006 #include    "cmd_io.h"
00007 #include    "globals.h"
00008 
00009 //************************************************************************
00010 //
00011 // get_cmd - read a command string from the serial port
00012 // =======
00013 // 
00014 // Method
00015 //      1. Read string of data until a Newline character
00016 //            string is passed as the parameter
00017 //      2. return a sting through the pointer and a count of the number of characters
00018 //
00019 // Notes
00020 //
00021 uint32_t get_cmd(CMD_STRUCT *command)
00022 {
00023 char   ch;
00024 uint8_t  i;
00025 //
00026 // read string and use newline as terminator
00027 //
00028     for (i= 0  ; i < CMD_STR_BUFFER_SZ ; i++) {
00029         ch = pc.getc();
00030         if (ch == '\r') {
00031             continue;
00032         }
00033         command->cmd_str[i] = ch;
00034         if (ch == '\n') {
00035             command->cmd_str[i] = '\0';
00036             break;
00037         }
00038     }
00039     command->char_cnt = i;    // record character count
00040     command->result_status = OK;
00041     return 0;
00042 }
00043 
00044 //************************************************************************
00045 //
00046 // parse_cmd - split command into its component parts
00047 // =========
00048 // 
00049 // Method
00050 //      1. first character is the command code
00051 //      2. subsequent character define a set of parameters
00052 //
00053 //        String is located in the CMD_STRUCT and the resulting
00054 //        data is returned to the same structure.
00055 //
00056 // Notes
00057 //
00058 uint32_t parse_cmd(CMD_STRUCT *command)
00059 {
00060 uint8_t  param_cnt, i, state;
00061 uint16_t tmp;
00062 
00063     command->cmd_code = command->cmd_str[0];
00064     param_cnt = 0;
00065     tmp = 0;
00066     state = 0;
00067     for (i=1 ; i < CMD_STR_BUFFER_SZ ; i++) {    // step through characters
00068         if (command->cmd_str[i] == '\0') {
00069             if (state == 1) {     // count paramter that is terminated by NEWLINE
00070                 command->param[param_cnt] = tmp;
00071                 param_cnt++;
00072             }
00073             command->nos_params = param_cnt;
00074             return OK;
00075         }
00076         if ((command->cmd_str[i] == ' ') && (state == 0)) {        // skip spaces
00077             continue;        
00078         }
00079         if ((command->cmd_str[i] == ' ') && (state == 1)) {        // skip spaces
00080             state = 0;
00081             command->param[param_cnt] = tmp;
00082             param_cnt++;
00083             tmp = 0;
00084             continue;        
00085         }
00086         state = 1;
00087         if ((command->cmd_str[i] >= '0') && (command->cmd_str[i] <= '9')) {
00088             tmp = (tmp * 10) + (command->cmd_str[i] - '0');
00089         } else {
00090             command->param[param_cnt] = tmp;
00091             return CMD_BAD_CHARACTER;
00092         }
00093     }
00094     return CMD_NO_TERMINATOR;
00095 }
00096 
00097 //************************************************************************
00098 //
00099 // reply_to_cmd - return data and status info
00100 // ============
00101 // 
00102 // Method
00103 //
00104 // Notes
00105 //
00106 void reply_to_cmd(CMD_STRUCT *command)
00107 {
00108     send_status(command->result_status);
00109     if ((command->result_status == OK) && (command->nos_data > 0)) {
00110         send_data(command);
00111     }
00112 }
00113 
00114 //************************************************************************
00115 //
00116 // send_status - command status
00117 // ===========
00118 //
00119 // Notes
00120 //        return status value as a positive interger in a string format
00121 //        with a terminating newline character.
00122 //
00123 void send_status(uint32_t  value)
00124 {
00125     pc.printf("%d\n", value);
00126     return;
00127 }
00128 
00129 //************************************************************************
00130 //
00131 // send_data - send data appropriate to the command 
00132 // =========
00133 // 
00134 // Method
00135 //
00136 // Notes
00137 //
00138 void send_data(CMD_STRUCT *command)
00139 {
00140 char buffer[80];
00141 uint8_t i;
00142 //
00143 // create data string
00144 //
00145     if (command->nos_data == 1) {
00146         sprintf(buffer, "%u\n", (int)command->result_data[0]);
00147     }
00148     if (command->nos_data == 2) {
00149         sprintf(buffer, "%u %u\n", (int)command->result_data[0], (int)command->result_data[1]);
00150     }
00151 /*     if (command->nos_data == 7) {
00152         sprintf(buffer, "%u %u %u %u %u %u %u\n", (int)command->result_data[0], (int)command->result_data[1], (int)command->result_data[2], (int)command->result_data[3], 
00153             (int)command->result_data[4], (int)command->result_data[5], (int)command->result_data[6]);
00154     }*/
00155 //
00156 // send string
00157 //
00158     for (i = 0 ; i < 40 ; i++) {
00159         if (buffer[i] == '\0') {    // do not send NULL character
00160             return;
00161         }
00162         pc.putc(buffer[i]);
00163     }
00164     return;
00165 }