Arkadi Rafalovich / Mbed 2 deprecated Serial_Packet_Example

Serial Packet Handler

Dependencies:   MbedJSONValue mbed

main.cpp@4:7d1077d2a30b, 2018-02-26 (annotated)

Committer:
Arkadi
Date:
Mon Feb 26 13:23:48 2018 +0000
Revision:
4:7d1077d2a30b
Parent:
3:632a7590a341 
Example How to work with json packets

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Arkadi 0:6080c5029b3f 1 ////////////////////////////////////////
Arkadi 2:c887a1b1b762 2 // Serial Packet - MbedJsonValue //
Arkadi 2:c887a1b1b762 3 // Arkadiraf@gmail.com - 15/06/2017 //
Arkadi 0:6080c5029b3f 4 ////////////////////////////////////////
Arkadi 0:6080c5029b3f 5 /*
Arkadi 0:6080c5029b3f 6 Construct packet from uart and parse with json format
Arkadi 0:6080c5029b3f 7 json:<PACKET>\r\n
Arkadi 3:632a7590a341 8 test with
Arkadi 4:7d1077d2a30b 9 json:{"my_array": ["demo_string", 10], "my_boolean": true}\r\n
Arkadi 0:6080c5029b3f 10 */
Arkadi 0:6080c5029b3f 11
Arkadi 0:6080c5029b3f 12 /*
Arkadi 0:6080c5029b3f 13 Board : Nucleo STM32F446RE
Arkadi 0:6080c5029b3f 14 */
Arkadi 0:6080c5029b3f 15
Arkadi 0:6080c5029b3f 16 /*
Arkadi 0:6080c5029b3f 17 Pinout:
Arkadi 0:6080c5029b3f 18 PC - Serial 2
Arkadi 0:6080c5029b3f 19 PA_2 (Tx) --> STLINK
Arkadi 0:6080c5029b3f 20 PA_3 (Rx) --> STLINK
Arkadi 0:6080c5029b3f 21 */
Arkadi 0:6080c5029b3f 22
Arkadi 1:711a27baa42d 23
Arkadi 0:6080c5029b3f 24 ///////////////
Arkadi 0:6080c5029b3f 25 // Libraries //
Arkadi 0:6080c5029b3f 26 ///////////////
Arkadi 0:6080c5029b3f 27 #include "mbed.h"
Arkadi 1:711a27baa42d 28 #include "MbedJSONValue.h"
Arkadi 4:7d1077d2a30b 29 //#include <string>
Arkadi 1:711a27baa42d 30
Arkadi 0:6080c5029b3f 31 //#include "BufferedSerial.h" // uart handler library
Arkadi 0:6080c5029b3f 32 ///////////////
Arkadi 0:6080c5029b3f 33 // #defines //
Arkadi 0:6080c5029b3f 34 ///////////////
Arkadi 0:6080c5029b3f 35
Arkadi 0:6080c5029b3f 36 #define DEBUG_MOD1
Arkadi 0:6080c5029b3f 37 #define MSG_BUFFER_SIZE 512
Arkadi 0:6080c5029b3f 38 #define HEADER_SIZE 5
Arkadi 0:6080c5029b3f 39 #define FOOTER_SIZE 2
Arkadi 0:6080c5029b3f 40
Arkadi 0:6080c5029b3f 41 /////////////
Arkadi 0:6080c5029b3f 42 // Objects //
Arkadi 0:6080c5029b3f 43 /////////////
Arkadi 0:6080c5029b3f 44
Arkadi 0:6080c5029b3f 45 // uart
Arkadi 0:6080c5029b3f 46 Serial pc(USBTX, USBRX);
Arkadi 0:6080c5029b3f 47
Arkadi 0:6080c5029b3f 48 // digital output
Arkadi 0:6080c5029b3f 49 DigitalOut led(PA_5);
Arkadi 0:6080c5029b3f 50 ///////////////
Arkadi 0:6080c5029b3f 51 // variables //
Arkadi 0:6080c5029b3f 52 ///////////////
Arkadi 0:6080c5029b3f 53
Arkadi 0:6080c5029b3f 54 // json buffer
Arkadi 0:6080c5029b3f 55 char json[MSG_BUFFER_SIZE];
Arkadi 0:6080c5029b3f 56
Arkadi 0:6080c5029b3f 57 // packet variables
Arkadi 0:6080c5029b3f 58 struct packetMSG_struct {
Arkadi 0:6080c5029b3f 59 // recieve message variables
Arkadi 0:6080c5029b3f 60 uint8_t header[HEADER_SIZE];
Arkadi 0:6080c5029b3f 61 uint8_t footer[FOOTER_SIZE];
Arkadi 0:6080c5029b3f 62 uint8_t syncIndex; // sync index for header / footer
Arkadi 0:6080c5029b3f 63 uint8_t syncFlag; // 0 - waiting for header, 1 - waiting for footer, 2 - verify footer, 3 - finish footer send to parser, flash buffer
Arkadi 0:6080c5029b3f 64 // buffer
Arkadi 0:6080c5029b3f 65 uint16_t bufferIndex; // buffer index
Arkadi 0:6080c5029b3f 66 uint8_t buffer[MSG_BUFFER_SIZE];
Arkadi 0:6080c5029b3f 67 } ;
Arkadi 0:6080c5029b3f 68 packetMSG_struct packetMSG;
Arkadi 0:6080c5029b3f 69 ///////////////
Arkadi 0:6080c5029b3f 70 // Functions //
Arkadi 0:6080c5029b3f 71 ///////////////
Arkadi 0:6080c5029b3f 72
Arkadi 0:6080c5029b3f 73 // Serial Event function
Arkadi 0:6080c5029b3f 74 void rxCallback(void);
Arkadi 0:6080c5029b3f 75
Arkadi 0:6080c5029b3f 76 // initialize packet struct
Arkadi 0:6080c5029b3f 77 void initPacket(void);
Arkadi 1:711a27baa42d 78
Arkadi 1:711a27baa42d 79 // Packet Parser
Arkadi 1:711a27baa42d 80 void parsePacket(void);
Arkadi 0:6080c5029b3f 81 ////////////////////////
Arkadi 0:6080c5029b3f 82 // Main Code Setup : //
Arkadi 0:6080c5029b3f 83 ////////////////////////
Arkadi 0:6080c5029b3f 84 int main()
Arkadi 0:6080c5029b3f 85 {
Arkadi 0:6080c5029b3f 86 // init packet:
Arkadi 0:6080c5029b3f 87 initPacket();
Arkadi 0:6080c5029b3f 88 // init uart
Arkadi 0:6080c5029b3f 89 pc.baud(57600);
Arkadi 0:6080c5029b3f 90 // attach serial event interrupt
Arkadi 0:6080c5029b3f 91 pc.attach(&rxCallback, Serial::RxIrq);
Arkadi 0:6080c5029b3f 92
Arkadi 0:6080c5029b3f 93 #ifdef DEBUG_MOD1
Arkadi 0:6080c5029b3f 94 pc.printf("UART Test \r\n");
Arkadi 0:6080c5029b3f 95 #endif
Arkadi 0:6080c5029b3f 96 ///////////////////////
Arkadi 0:6080c5029b3f 97 // Main Code Loop : //
Arkadi 0:6080c5029b3f 98 ///////////////////////
Arkadi 0:6080c5029b3f 99 while(1) {
Arkadi 0:6080c5029b3f 100 //sleep();
Arkadi 0:6080c5029b3f 101 }// end main loop
Arkadi 0:6080c5029b3f 102 }// end main
Arkadi 1:711a27baa42d 103
Arkadi 1:711a27baa42d 104
Arkadi 1:711a27baa42d 105
Arkadi 0:6080c5029b3f 106 ///////////////
Arkadi 0:6080c5029b3f 107 // Functions //
Arkadi 0:6080c5029b3f 108 ///////////////
Arkadi 0:6080c5029b3f 109
Arkadi 0:6080c5029b3f 110 // Serial Event function
Arkadi 0:6080c5029b3f 111 void rxCallback(void)
Arkadi 0:6080c5029b3f 112 {
Arkadi 0:6080c5029b3f 113 while (pc.readable()) {
Arkadi 0:6080c5029b3f 114 // read icoming
Arkadi 0:6080c5029b3f 115 led = !led;
Arkadi 0:6080c5029b3f 116 uint8_t in_byte = pc.getc();
Arkadi 0:6080c5029b3f 117 #ifdef DEBUG_MOD1
Arkadi 0:6080c5029b3f 118 pc.putc(in_byte);
Arkadi 0:6080c5029b3f 119 #endif
Arkadi 0:6080c5029b3f 120 // detect start message , end message
Arkadi 0:6080c5029b3f 121 switch (packetMSG.syncFlag) {
Arkadi 0:6080c5029b3f 122 // waiting for header
Arkadi 0:6080c5029b3f 123 case 0: {
Arkadi 0:6080c5029b3f 124 if (packetMSG.header[packetMSG.syncIndex] == in_byte) {
Arkadi 0:6080c5029b3f 125 packetMSG.syncIndex++;
Arkadi 0:6080c5029b3f 126 if (packetMSG.syncIndex == HEADER_SIZE) { // finish header SYNC
Arkadi 0:6080c5029b3f 127 packetMSG.syncFlag = 1; // start collecting data, wait for footer
Arkadi 0:6080c5029b3f 128 packetMSG.bufferIndex = 0;
Arkadi 0:6080c5029b3f 129 packetMSG.syncIndex=0;
Arkadi 0:6080c5029b3f 130 }
Arkadi 0:6080c5029b3f 131 } else { // reinit sync
Arkadi 0:6080c5029b3f 132 packetMSG.syncIndex=0;
Arkadi 0:6080c5029b3f 133 }
Arkadi 0:6080c5029b3f 134 //pc.printf("case 0 , %d \r\n",packetMSG.syncIndex);
Arkadi 0:6080c5029b3f 135 break;
Arkadi 1:711a27baa42d 136 }
Arkadi 0:6080c5029b3f 137 // waiting for footer
Arkadi 0:6080c5029b3f 138 case 1: {
Arkadi 0:6080c5029b3f 139 // add byte to buffer
Arkadi 0:6080c5029b3f 140 packetMSG.buffer[packetMSG.bufferIndex] = in_byte;
Arkadi 0:6080c5029b3f 141 packetMSG.bufferIndex++;
Arkadi 0:6080c5029b3f 142 if (packetMSG.bufferIndex >= MSG_BUFFER_SIZE) { // buffer overflow
Arkadi 0:6080c5029b3f 143 // reset buffer
Arkadi 0:6080c5029b3f 144 packetMSG.bufferIndex = 0;
Arkadi 0:6080c5029b3f 145 packetMSG.syncIndex = 0;
Arkadi 0:6080c5029b3f 146 packetMSG.syncFlag = 0;
Arkadi 0:6080c5029b3f 147 } else if (packetMSG.footer[packetMSG.syncIndex] == in_byte) { // footer char recieved
Arkadi 0:6080c5029b3f 148 packetMSG.syncIndex++;
Arkadi 0:6080c5029b3f 149 packetMSG.syncFlag=2; // move to verify footer
Arkadi 0:6080c5029b3f 150 }
Arkadi 0:6080c5029b3f 151 //pc.printf("case 2 , %d \r\n",packetMSG.syncIndex);
Arkadi 0:6080c5029b3f 152 break;
Arkadi 1:711a27baa42d 153 }
Arkadi 0:6080c5029b3f 154 // verify footer
Arkadi 0:6080c5029b3f 155 case 2: {
Arkadi 0:6080c5029b3f 156 // add byte to buffer
Arkadi 0:6080c5029b3f 157 packetMSG.buffer[packetMSG.bufferIndex] = in_byte;
Arkadi 0:6080c5029b3f 158 packetMSG.bufferIndex++;
Arkadi 0:6080c5029b3f 159 if (packetMSG.bufferIndex >= MSG_BUFFER_SIZE) { // buffer overflow
Arkadi 0:6080c5029b3f 160 // reset buffer
Arkadi 0:6080c5029b3f 161 packetMSG.bufferIndex = 0;
Arkadi 0:6080c5029b3f 162 packetMSG.syncIndex = 0;
Arkadi 0:6080c5029b3f 163 packetMSG.syncFlag = 0;
Arkadi 0:6080c5029b3f 164 } else if (packetMSG.footer[packetMSG.syncIndex] == in_byte) { // footer char recieved
Arkadi 0:6080c5029b3f 165 packetMSG.syncIndex++;
Arkadi 0:6080c5029b3f 166 if (packetMSG.syncIndex == FOOTER_SIZE) { // finish footer SYNC
Arkadi 0:6080c5029b3f 167 packetMSG.syncFlag = 3;
Arkadi 1:711a27baa42d 168 // copy packet to json buffer
Arkadi 0:6080c5029b3f 169 memcpy (&json, &packetMSG.buffer, packetMSG.bufferIndex);
Arkadi 1:711a27baa42d 170 json[packetMSG.bufferIndex]=NULL; // end with NULL to indicate end of string
Arkadi 0:6080c5029b3f 171 // copy packet to json buffer with sprintf
Arkadi 0:6080c5029b3f 172 //sprintf(json, "%.*s", packetMSG.bufferIndex, packetMSG.buffer );
Arkadi 0:6080c5029b3f 173 // send msg to parse.
Arkadi 1:711a27baa42d 174 parsePacket();
Arkadi 0:6080c5029b3f 175 // reset buffer
Arkadi 0:6080c5029b3f 176 packetMSG.bufferIndex = 0;
Arkadi 0:6080c5029b3f 177 packetMSG.syncIndex = 0;
Arkadi 0:6080c5029b3f 178 packetMSG.syncFlag = 0;
Arkadi 0:6080c5029b3f 179 }
Arkadi 0:6080c5029b3f 180 } else { // footer broke restart wait for footer
Arkadi 0:6080c5029b3f 181 packetMSG.syncFlag=1;
Arkadi 0:6080c5029b3f 182 // verify that it didnt broke on first footer char
Arkadi 0:6080c5029b3f 183 if (packetMSG.footer[0] == in_byte) {
Arkadi 0:6080c5029b3f 184 packetMSG.syncIndex=1;
Arkadi 0:6080c5029b3f 185 } else {
Arkadi 0:6080c5029b3f 186 packetMSG.syncIndex=0;
Arkadi 0:6080c5029b3f 187 }
Arkadi 0:6080c5029b3f 188 }
Arkadi 0:6080c5029b3f 189 break;
Arkadi 1:711a27baa42d 190 }
Arkadi 0:6080c5029b3f 191 default: {
Arkadi 0:6080c5029b3f 192 pc.printf("Sonmething went wrong \r\n");
Arkadi 0:6080c5029b3f 193 break;
Arkadi 0:6080c5029b3f 194 }
Arkadi 0:6080c5029b3f 195 } // end switch
Arkadi 0:6080c5029b3f 196 }// end uart readable
Arkadi 0:6080c5029b3f 197 } // end rxCallback
Arkadi 0:6080c5029b3f 198
Arkadi 0:6080c5029b3f 199
Arkadi 0:6080c5029b3f 200 // initialize packet struct
Arkadi 0:6080c5029b3f 201 void initPacket(void)
Arkadi 0:6080c5029b3f 202 {
Arkadi 0:6080c5029b3f 203 // init variables to default:
Arkadi 0:6080c5029b3f 204 packetMSG.header[0] = 'j';
Arkadi 0:6080c5029b3f 205 packetMSG.header[1] = 's';
Arkadi 0:6080c5029b3f 206 packetMSG.header[2] = 'o';
Arkadi 0:6080c5029b3f 207 packetMSG.header[3] = 'n';
Arkadi 0:6080c5029b3f 208 packetMSG.header[4] = ':';
Arkadi 0:6080c5029b3f 209
Arkadi 0:6080c5029b3f 210 packetMSG.footer[0]= 13; // /r
Arkadi 0:6080c5029b3f 211 packetMSG.footer[1]= 10; // /n
Arkadi 0:6080c5029b3f 212
Arkadi 0:6080c5029b3f 213 packetMSG.syncIndex=0; // sync index for header / footer
Arkadi 0:6080c5029b3f 214 packetMSG.syncFlag=0; // 0 - waiting for header, 1 - waiting for footer, 2 - verify footer, 3 - finish footer send to parser, flash buffer
Arkadi 0:6080c5029b3f 215 packetMSG.bufferIndex=0; // buffer index
Arkadi 1:711a27baa42d 216 }
Arkadi 1:711a27baa42d 217
Arkadi 1:711a27baa42d 218 // Packet Parser
Arkadi 1:711a27baa42d 219 void parsePacket(void)
Arkadi 1:711a27baa42d 220 {
Arkadi 1:711a27baa42d 221 #ifdef DEBUG_MOD1
Arkadi 1:711a27baa42d 222 // write buffer to screen
Arkadi 1:711a27baa42d 223 //pc.printf("%d, %.*s", packetMSG.bufferIndex ,packetMSG.bufferIndex, packetMSG.buffer );
Arkadi 4:7d1077d2a30b 224 //pc.printf("%s", json);
Arkadi 1:711a27baa42d 225 #endif
Arkadi 1:711a27baa42d 226
Arkadi 3:632a7590a341 227 MbedJSONValue demo;
Arkadi 1:711a27baa42d 228
Arkadi 3:632a7590a341 229 //const char * json = "{\"my_array\": [\"demo_string\", 10], \"my_boolean\": true}";
Arkadi 3:632a7590a341 230 // json:{"my_array": ["demo_string", 10], "my_boolean": true}
Arkadi 3:632a7590a341 231 //parse the previous string and fill the object demo
Arkadi 3:632a7590a341 232 parse(demo, json);
Arkadi 1:711a27baa42d 233
Arkadi 4:7d1077d2a30b 234 // string my_str;
Arkadi 4:7d1077d2a30b 235 // int my_int;
Arkadi 4:7d1077d2a30b 236 // bool my_bool;
Arkadi 4:7d1077d2a30b 237 //
Arkadi 4:7d1077d2a30b 238 // my_str = demo["my_array"][0].get<std::string>();
Arkadi 4:7d1077d2a30b 239 // my_int = demo["my_array"][1].get<int>();
Arkadi 4:7d1077d2a30b 240 // my_bool = demo["my_boolean"].get<bool>();
Arkadi 4:7d1077d2a30b 241 //
Arkadi 4:7d1077d2a30b 242 // printf("my_str: %s\r\n", my_str.c_str());
Arkadi 4:7d1077d2a30b 243 // printf("my_int: %d\r\n", my_int);
Arkadi 4:7d1077d2a30b 244 // printf("my_bool: %s\r\n", my_bool ? "true" : "false");
Arkadi 3:632a7590a341 245
Arkadi 0:6080c5029b3f 246 }