voor willem test
Dependencies: 4DGL MODSERIAL mbed mbos
USB_receive_2.cpp@6:e0bf3b244d7c, 2013-01-29 (annotated)
- Committer:
- LvdK
- Date:
- Tue Jan 29 14:54:14 2013 +0000
- Revision:
- 6:e0bf3b244d7c
Goed werkende mbos versie met 0.5 sec ALIVE message
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
LvdK | 6:e0bf3b244d7c | 1 | // L. van der Kolk, ELVEDEKA, Holland // |
LvdK | 6:e0bf3b244d7c | 2 | // File: USB_receive_2.cpp Mbos version |
LvdK | 6:e0bf3b244d7c | 3 | |
LvdK | 6:e0bf3b244d7c | 4 | #include "mbed.h" |
LvdK | 6:e0bf3b244d7c | 5 | #include "MODSERIAL.h" // : Note: import lib of Erk Olieman V1.25 to prevent compiler error! |
LvdK | 6:e0bf3b244d7c | 6 | |
LvdK | 6:e0bf3b244d7c | 7 | // Instantiate USB communication defined by Mbed USB TX and RX lines |
LvdK | 6:e0bf3b244d7c | 8 | // with TX and RX ringbuffers : |
LvdK | 6:e0bf3b244d7c | 9 | MODSERIAL USB(USBTX, USBRX, 256, 512); |
LvdK | 6:e0bf3b244d7c | 10 | |
LvdK | 6:e0bf3b244d7c | 11 | void decode_string(int nummer_of_chars); |
LvdK | 6:e0bf3b244d7c | 12 | void read_datafields(int command_number); |
LvdK | 6:e0bf3b244d7c | 13 | |
LvdK | 6:e0bf3b244d7c | 14 | #define max_string_length 80 // : max length of received string starting with $ and ending with CR/LF |
LvdK | 6:e0bf3b244d7c | 15 | #define min_string_length 10 // : min length of received string starting with $ and ending with CR/LF |
LvdK | 6:e0bf3b244d7c | 16 | char string_received[max_string_length + 2]; // : holds received string starting with $ and ending with CR/LF |
LvdK | 6:e0bf3b244d7c | 17 | |
LvdK | 6:e0bf3b244d7c | 18 | int receive_flag = false; // : global flag, signals a receive 'event' |
LvdK | 6:e0bf3b244d7c | 19 | |
LvdK | 6:e0bf3b244d7c | 20 | #define max_commas 10 // : max. nr of possible field separating commas in a valid message string to CDU |
LvdK | 6:e0bf3b244d7c | 21 | int comma[max_commas]; // : array with positions of all found commas in string_receved[] |
LvdK | 6:e0bf3b244d7c | 22 | #define message_header "$PCDU" // : common message header in all messages |
LvdK | 6:e0bf3b244d7c | 23 | |
LvdK | 6:e0bf3b244d7c | 24 | #define max_nr_of_commands 16 // : max nr of possible FS-to-CDU commands |
LvdK | 6:e0bf3b244d7c | 25 | // Define array of pointers to possible FS-to-CDU commands with 3 characters: |
LvdK | 6:e0bf3b244d7c | 26 | const char *command[max_nr_of_commands] = { |
LvdK | 6:e0bf3b244d7c | 27 | "123", // : no valid CDU command nr. 0 , used for debugging only |
LvdK | 6:e0bf3b244d7c | 28 | "MSG", // : command nr. 1 |
LvdK | 6:e0bf3b244d7c | 29 | "EXC", // : command nr. 2 |
LvdK | 6:e0bf3b244d7c | 30 | "BLT", // : command nr. 3 |
LvdK | 6:e0bf3b244d7c | 31 | "SBY", // : command nr. 4 |
LvdK | 6:e0bf3b244d7c | 32 | "CLS", // : command nr. 5 |
LvdK | 6:e0bf3b244d7c | 33 | "SBC", // : command nr. 6 |
LvdK | 6:e0bf3b244d7c | 34 | "WTX", // : command nr. 7 |
LvdK | 6:e0bf3b244d7c | 35 | "ETX", // : command nr. 8 |
LvdK | 6:e0bf3b244d7c | 36 | "KTX", // : command nr. 9 |
LvdK | 6:e0bf3b244d7c | 37 | "STV", // : command nr. 10 |
LvdK | 6:e0bf3b244d7c | 38 | "GTV", // : command nr. 11 |
LvdK | 6:e0bf3b244d7c | 39 | }; |
LvdK | 6:e0bf3b244d7c | 40 | |
LvdK | 6:e0bf3b244d7c | 41 | void collect_FSdata() { |
LvdK | 6:e0bf3b244d7c | 42 | // Function reads data from the RX buffer |
LvdK | 6:e0bf3b244d7c | 43 | // and collects strings starting with $ and ending with CR/LF. |
LvdK | 6:e0bf3b244d7c | 44 | // Strings shorter than min_string_length or longer than |
LvdK | 6:e0bf3b244d7c | 45 | // max_string_length will be ignored, others will be decoded further. |
LvdK | 6:e0bf3b244d7c | 46 | static int $_detected = false; // : no valid begin of string detected (init only on first call) |
LvdK | 6:e0bf3b244d7c | 47 | static int string_pntr = 0; // : pointer at begin of string (init only on first call) |
LvdK | 6:e0bf3b244d7c | 48 | static int nr_of_received_char = 0; // : counter of received characters (init only on first call) |
LvdK | 6:e0bf3b244d7c | 49 | char rx_char; |
LvdK | 6:e0bf3b244d7c | 50 | |
LvdK | 6:e0bf3b244d7c | 51 | while ( !USB.rxBufferEmpty() ) |
LvdK | 6:e0bf3b244d7c | 52 | { rx_char = USB.getc(); // : get a char from Rx buffer |
LvdK | 6:e0bf3b244d7c | 53 | //USB.putc(rx_char); // : unprotected (!) immediate echo of char in case of debugging <<< |
LvdK | 6:e0bf3b244d7c | 54 | // Check for string starting with $ char: |
LvdK | 6:e0bf3b244d7c | 55 | if ( rx_char == '$' && $_detected == false ){ |
LvdK | 6:e0bf3b244d7c | 56 | $_detected = true; // : begin of string is detected |
LvdK | 6:e0bf3b244d7c | 57 | string_pntr = 0; // : set pointer to begin of string_received[] buffer |
LvdK | 6:e0bf3b244d7c | 58 | } |
LvdK | 6:e0bf3b244d7c | 59 | string_received[string_pntr] = rx_char; |
LvdK | 6:e0bf3b244d7c | 60 | string_pntr++; |
LvdK | 6:e0bf3b244d7c | 61 | |
LvdK | 6:e0bf3b244d7c | 62 | if (string_pntr >= max_string_length) { |
LvdK | 6:e0bf3b244d7c | 63 | // command string looks too long, so start all over again: |
LvdK | 6:e0bf3b244d7c | 64 | string_pntr = 0; // : set pointer back to begin of string_received[] again |
LvdK | 6:e0bf3b244d7c | 65 | nr_of_received_char = 0; // : reset number of received chars |
LvdK | 6:e0bf3b244d7c | 66 | $_detected = false; |
LvdK | 6:e0bf3b244d7c | 67 | } |
LvdK | 6:e0bf3b244d7c | 68 | |
LvdK | 6:e0bf3b244d7c | 69 | if ( rx_char == '\n' && $_detected == true ) { |
LvdK | 6:e0bf3b244d7c | 70 | if ( string_pntr > min_string_length ) { // : check minimum string length |
LvdK | 6:e0bf3b244d7c | 71 | // Received string can be interesting now because |
LvdK | 6:e0bf3b244d7c | 72 | // it starts with '$' AND it ends on New-Line AND |
LvdK | 6:e0bf3b244d7c | 73 | // it has a minimum length AND it is not too long: |
LvdK | 6:e0bf3b244d7c | 74 | string_received[string_pntr] = '\0'; // : mark end of string |
LvdK | 6:e0bf3b244d7c | 75 | // USB.printf("string_received : %s",string_received ); // show string for debugging << |
LvdK | 6:e0bf3b244d7c | 76 | nr_of_received_char = string_pntr; |
LvdK | 6:e0bf3b244d7c | 77 | //Call decoder to analyse this string: |
LvdK | 6:e0bf3b244d7c | 78 | decode_string(nr_of_received_char); |
LvdK | 6:e0bf3b244d7c | 79 | |
LvdK | 6:e0bf3b244d7c | 80 | // Get ready for receiving new commands: |
LvdK | 6:e0bf3b244d7c | 81 | $_detected = false; |
LvdK | 6:e0bf3b244d7c | 82 | string_pntr = 0; // : set pointer back to begin of string_received[] again |
LvdK | 6:e0bf3b244d7c | 83 | nr_of_received_char = 0; // : reset number of received chars |
LvdK | 6:e0bf3b244d7c | 84 | } |
LvdK | 6:e0bf3b244d7c | 85 | else { |
LvdK | 6:e0bf3b244d7c | 86 | $_detected = false; |
LvdK | 6:e0bf3b244d7c | 87 | string_pntr = 0; // : set pointer back to begin of string_received[] again |
LvdK | 6:e0bf3b244d7c | 88 | nr_of_received_char = 0; // : reset number of received chars |
LvdK | 6:e0bf3b244d7c | 89 | } |
LvdK | 6:e0bf3b244d7c | 90 | } |
LvdK | 6:e0bf3b244d7c | 91 | } |
LvdK | 6:e0bf3b244d7c | 92 | } |
LvdK | 6:e0bf3b244d7c | 93 | |
LvdK | 6:e0bf3b244d7c | 94 | void decode_string(int nummer_of_chars) |
LvdK | 6:e0bf3b244d7c | 95 | { // -- This function decodes a received $.....CR/LF string written in string_received[] -- |
LvdK | 6:e0bf3b244d7c | 96 | // First it checks for a valid checksum and reads the positions of commas in the string. |
LvdK | 6:e0bf3b244d7c | 97 | // When checksum is OK, it will continue to look for valid 3 char FS-to-CDU commands. |
LvdK | 6:e0bf3b244d7c | 98 | // When a valid command is found, data fields will be analyzed further using the found positions |
LvdK | 6:e0bf3b244d7c | 99 | // of commas in the string. |
LvdK | 6:e0bf3b244d7c | 100 | int i,c, equal; |
LvdK | 6:e0bf3b244d7c | 101 | char byte_read, exor_byte; |
LvdK | 6:e0bf3b244d7c | 102 | char command_string[6], received_checksum[4], calc_checksum[4]; |
LvdK | 6:e0bf3b244d7c | 103 | |
LvdK | 6:e0bf3b244d7c | 104 | // Get checksum and position of commas in string_received[] : |
LvdK | 6:e0bf3b244d7c | 105 | exor_byte = 0; |
LvdK | 6:e0bf3b244d7c | 106 | i = 1; // : i points to first char after $ |
LvdK | 6:e0bf3b244d7c | 107 | c = 1; // : position of first comma |
LvdK | 6:e0bf3b244d7c | 108 | do { |
LvdK | 6:e0bf3b244d7c | 109 | byte_read = string_received[i]; |
LvdK | 6:e0bf3b244d7c | 110 | if (byte_read == ',' && c < max_commas) { |
LvdK | 6:e0bf3b244d7c | 111 | comma[c] = i; |
LvdK | 6:e0bf3b244d7c | 112 | c++; |
LvdK | 6:e0bf3b244d7c | 113 | } |
LvdK | 6:e0bf3b244d7c | 114 | if (byte_read == '*') break; |
LvdK | 6:e0bf3b244d7c | 115 | exor_byte = exor_byte ^ byte_read; |
LvdK | 6:e0bf3b244d7c | 116 | i++; |
LvdK | 6:e0bf3b244d7c | 117 | } while ( i < nummer_of_chars ); |
LvdK | 6:e0bf3b244d7c | 118 | //USB.printf("commas found : %d\n",c-1 ); // : show commas for debugging <<<<<< |
LvdK | 6:e0bf3b244d7c | 119 | i++; // : i points to first checksum char after * char |
LvdK | 6:e0bf3b244d7c | 120 | strncpy(received_checksum,&string_received[i],2); // : copy 2 char checksum after * |
LvdK | 6:e0bf3b244d7c | 121 | // Get calculated checksum by transforming exor_byte in 2 hex chars (with upper case A-F) : |
LvdK | 6:e0bf3b244d7c | 122 | sprintf(calc_checksum,"%02X",exor_byte); // : + extra NULL char added by sprintf |
LvdK | 6:e0bf3b244d7c | 123 | equal = strncmp(received_checksum,calc_checksum,2); |
LvdK | 6:e0bf3b244d7c | 124 | if (equal != 0) { |
LvdK | 6:e0bf3b244d7c | 125 | //USB.printf("checksum is NOT OK ! \n" ); // : show message for debugging <<< |
LvdK | 6:e0bf3b244d7c | 126 | } |
LvdK | 6:e0bf3b244d7c | 127 | else { // checksum is OK, go on: |
LvdK | 6:e0bf3b244d7c | 128 | // Check for 5 char "$PCDU" header: |
LvdK | 6:e0bf3b244d7c | 129 | equal = strncmp(string_received,message_header,strlen(message_header)); |
LvdK | 6:e0bf3b244d7c | 130 | if (equal != 0) { |
LvdK | 6:e0bf3b244d7c | 131 | // USB.printf("no $PCDU header in message !\n" ); // : show message for debugging <<< |
LvdK | 6:e0bf3b244d7c | 132 | } |
LvdK | 6:e0bf3b244d7c | 133 | else { |
LvdK | 6:e0bf3b244d7c | 134 | // Read 3 char command after message_header: |
LvdK | 6:e0bf3b244d7c | 135 | strncpy(command_string,&string_received[strlen(message_header)],3); |
LvdK | 6:e0bf3b244d7c | 136 | //USB.printf("command found : %3s\n",command_string ); // : show command for debugging <<< |
LvdK | 6:e0bf3b244d7c | 137 | // Compare found string with known 3 char command list: |
LvdK | 6:e0bf3b244d7c | 138 | i = 0; |
LvdK | 6:e0bf3b244d7c | 139 | do { |
LvdK | 6:e0bf3b244d7c | 140 | equal = strncmp(&command_string[0],command[i],3); |
LvdK | 6:e0bf3b244d7c | 141 | if( equal == 0) break; |
LvdK | 6:e0bf3b244d7c | 142 | i++; |
LvdK | 6:e0bf3b244d7c | 143 | } while ( i < max_nr_of_commands); |
LvdK | 6:e0bf3b244d7c | 144 | //USB.printf("command number is : %d\n",i ); // : show command nr for debugging <<< |
LvdK | 6:e0bf3b244d7c | 145 | if (equal == 0) { |
LvdK | 6:e0bf3b244d7c | 146 | // Command is known now, so now read all data fields: |
LvdK | 6:e0bf3b244d7c | 147 | read_datafields(i); |
LvdK | 6:e0bf3b244d7c | 148 | } |
LvdK | 6:e0bf3b244d7c | 149 | } |
LvdK | 6:e0bf3b244d7c | 150 | } |
LvdK | 6:e0bf3b244d7c | 151 | |
LvdK | 6:e0bf3b244d7c | 152 | receive_flag = false; |
LvdK | 6:e0bf3b244d7c | 153 | } |
LvdK | 6:e0bf3b244d7c | 154 | |
LvdK | 6:e0bf3b244d7c | 155 |