Control a robot over the internet using UDP and a Wifly module (WiFi).

Dependencies:   Motor TextLCD WiflyInterface mbed-rtos mbed

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Wifly.cpp

00001 /* Copyright (C) 2012 mbed.org, MIT License
00002  *
00003  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00004  * and associated documentation files (the "Software"), to deal in the Software without restriction,
00005  * including without limitation the rights to use, copy, modify, merge, publish, distribute,
00006  * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
00007  * furnished to do so, subject to the following conditions:
00008  *
00009  * The above copyright notice and this permission notice shall be included in all copies or
00010  * substantial portions of the Software.
00011  *
00012  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00013  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00014  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00015  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00016  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017  */
00018 
00019 #include "mbed.h"
00020 #include "Wifly.h"
00021 #include <string>
00022 #include <algorithm>
00023 
00024 //Debug is disabled by default
00025 #if (0 && !defined(TARGET_LPC11U24))
00026 #define DBG(x, ...) std::printf("[Wifly : DBG]"x"\r\n", ##__VA_ARGS__);
00027 #define WARN(x, ...) std::printf("[Wifly : WARN]"x"\r\n", ##__VA_ARGS__);
00028 #define ERR(x, ...) std::printf("[Wifly : ERR]"x"\r\n", ##__VA_ARGS__);
00029 #else
00030 #define DBG(x, ...)
00031 #define WARN(x, ...)
00032 #define ERR(x, ...)
00033 #endif
00034 
00035 #if !defined(TARGET_LPC11U24)
00036 #define INFO(x, ...) printf("[Wifly : INFO]"x"\r\n", ##__VA_ARGS__);
00037 #else
00038 #define INFO(x, ...)
00039 #endif
00040 
00041 #define MAX_TRY_JOIN 3
00042 
00043 Wifly * Wifly::inst;
00044 
00045 Wifly::Wifly(   PinName tx, PinName rx, PinName _reset, PinName tcp_status, const char * ssid, const char * phrase, Security sec):
00046     wifi(tx, rx), reset_pin(_reset), tcp_status(tcp_status), buf_wifly(256)
00047 {
00048     memset(&state, 0, sizeof(state));
00049     state.sec = sec;
00050 
00051     // change all ' ' in '$' in the ssid and the passphrase
00052     strcpy(this->ssid, ssid);
00053     for (int i = 0; i < strlen(ssid); i++) {
00054         if (this->ssid[i] == ' ')
00055             this->ssid[i] = '$';
00056     }
00057     strcpy(this->phrase, phrase);
00058     for (int i = 0; i < strlen(phrase); i++) {
00059         if (this->phrase[i] == ' ')
00060             this->phrase[i] = '$';
00061     }
00062 
00063     inst = this;
00064     attach_rx(false);
00065     state.cmd_mode = false;
00066 }
00067 
00068 bool Wifly::join()
00069 {
00070     char cmd[20];
00071 
00072     for (int i= 0; i < MAX_TRY_JOIN; i++) {
00073 
00074         // no auto join
00075         if (!sendCommand("set w j 0\r", "AOK"))
00076             continue;
00077 
00078         //no echo
00079         if (!sendCommand("set u m 1\r", "AOK"))
00080             continue;
00081 
00082         // set time
00083         if (!sendCommand("set c t 30\r", "AOK"))
00084             continue;
00085 
00086         // set size
00087         if (!sendCommand("set c s 1024\r", "AOK"))
00088             continue;
00089 
00090         // red led on when tcp connection active
00091         if (!sendCommand("set s i 0x40\r", "AOK"))
00092             continue;
00093 
00094         // no string sent to the tcp client
00095         if (!sendCommand("set c r 0\r", "AOK"))
00096             continue;
00097 
00098         // tcp protocol
00099         if (!sendCommand("set i p 2\r", "AOK"))
00100             continue;
00101 
00102         // tcp retry
00103         if (!sendCommand("set i f 0x7\r", "AOK"))
00104             continue;
00105             
00106         // set dns server
00107         if (!sendCommand("set d n rn.microchip.com\r", "AOK"))
00108             continue;
00109 
00110         //dhcp
00111         sprintf(cmd, "set i d %d\r", (state.dhcp) ? 1 : 0);
00112         if (!sendCommand(cmd, "AOK"))
00113             continue;
00114 
00115         // ssid
00116         sprintf(cmd, "set w s %s\r", ssid);
00117         if (!sendCommand(cmd, "AOK"))
00118             continue;
00119 
00120         //auth
00121         sprintf(cmd, "set w a %d\r", state.sec);
00122         if (!sendCommand(cmd, "AOK"))
00123             continue;
00124 
00125         // if no dhcp, set ip, netmask and gateway
00126         if (!state.dhcp) {
00127             DBG("not dhcp\r");
00128 
00129             sprintf(cmd, "set i a %s\r\n", ip);
00130             if (!sendCommand(cmd, "AOK"))
00131                 continue;
00132 
00133             sprintf(cmd, "set i n %s\r", netmask);
00134             if (!sendCommand(cmd, "AOK"))
00135                 continue;
00136 
00137             sprintf(cmd, "set i g %s\r", gateway);
00138             if (!sendCommand(cmd, "AOK"))
00139                 continue;
00140         }
00141 
00142         //key step
00143         if (state.sec != NONE) {
00144             if (state.sec == WPA)
00145                 sprintf(cmd, "set w p %s\r", phrase);
00146             else if (state.sec == WEP_128)
00147                 sprintf(cmd, "set w k %s\r", phrase);
00148 
00149             if (!sendCommand(cmd, "AOK"))
00150                 continue;
00151         }
00152 
00153         //join the network (10s timeout)
00154         if (state.dhcp) {
00155             if (!sendCommand("join\r", "DHCP=ON", NULL, 10000))
00156                 continue;
00157         } else {
00158             if (!sendCommand("join\r", "Associated", NULL, 10000))
00159                 continue;
00160         }
00161 
00162         if (!sendCommand("save\r", "Stor"))
00163             continue;
00164 
00165         exit();
00166 
00167         state.associated = true;
00168         INFO("\r\nssid: %s\r\nphrase: %s\r\nsecurity: %s\r\n\r\n", this->ssid, this->phrase, getStringSecurity());
00169         return true;
00170     }
00171     return false;
00172 }
00173 
00174 
00175 bool Wifly::setProtocol(Protocol p)
00176 {
00177     // use udp auto pairing
00178     char cmd[20];
00179     sprintf(cmd, "set i p %d\r", p);
00180     if (!sendCommand(cmd, "AOK"))
00181         return false;
00182 
00183     switch(p) {
00184         case TCP:
00185             // set ip flags: tcp retry enabled
00186             if (!sendCommand("set i f 0x07\r", "AOK"))
00187                 return false;
00188             break;
00189         case UDP:
00190             // set ip flags: udp auto pairing enabled
00191             if (!sendCommand("set i h 0.0.0.0\r", "AOK"))
00192                 return false;
00193             if (!sendCommand("set i f 0x40\r", "AOK"))
00194                 return false;
00195             break;
00196     }
00197     state.proto = p;
00198     return true;
00199 }
00200 
00201 char * Wifly::getStringSecurity()
00202 {
00203     switch(state.sec) {
00204         case NONE:
00205             return "NONE";
00206         case WEP_128:
00207             return "WEP_128";
00208         case WPA:
00209             return "WPA";
00210     }
00211     return "UNKNOWN";
00212 }
00213 
00214 bool Wifly::connect(const char * host, int port)
00215 {
00216     char rcv[20];
00217     char cmd[20];
00218 
00219     // try to open
00220     sprintf(cmd, "open %s %d\r", host, port);
00221     if (sendCommand(cmd, "OPEN", NULL, 10000)) {
00222         state.tcp = true;
00223         state.cmd_mode = false;
00224         return true;
00225     }
00226 
00227     // if failed, retry and parse the response
00228     if (sendCommand(cmd, NULL, rcv, 5000)) {
00229         if (strstr(rcv, "OPEN") == NULL) {
00230             if (strstr(rcv, "Connected") != NULL) {
00231                 wait(0.25);
00232                 if (!sendCommand("close\r", "CLOS"))
00233                     return false;
00234                 wait(0.25);
00235                 if (!sendCommand(cmd, "OPEN", NULL, 10000))
00236                     return false;
00237             } else {
00238                 return false;
00239             }
00240         }
00241     } else {
00242         return false;
00243     }
00244 
00245     state.tcp = true;
00246     state.cmd_mode = false;
00247 
00248     return true;
00249 }
00250 
00251 
00252 bool Wifly::gethostbyname(const char * host, char * ip)
00253 {
00254     string h = host;
00255     char cmd[30], rcv[100];
00256     int l = 0;
00257     char * point;
00258     int nb_digits = 0;
00259 
00260     // no dns needed
00261     int pos = h.find(".");
00262     if (pos != string::npos) {
00263         string sub = h.substr(0, h.find("."));
00264         nb_digits = atoi(sub.c_str());
00265     }
00266     //printf("substrL %s\r\n", sub.c_str());
00267     if (count(h.begin(), h.end(), '.') == 3 && nb_digits > 0) {
00268         strcpy(ip, host);
00269     }
00270     // dns needed
00271     else {
00272         nb_digits = 0;
00273         sprintf(cmd, "lookup %s\r", host);
00274         if (!sendCommand(cmd, NULL, rcv))
00275             return false;
00276 
00277         // look for the ip address
00278         char * begin = strstr(rcv, "=") + 1;
00279         for (int i = 0; i < 3; i++) {
00280             point = strstr(begin + l, ".");
00281             DBG("str: %s", begin + l);
00282             l += point - (begin + l) + 1;
00283         }
00284         DBG("str: %s", begin + l);
00285         while(*(begin + l + nb_digits) >= '0' && *(begin + l + nb_digits) <= '9') {
00286             DBG("digit: %c", *(begin + l + nb_digits));
00287             nb_digits++;
00288         }
00289         memcpy(ip, begin, l + nb_digits);
00290         ip[l+nb_digits] = 0;
00291         DBG("ip from dns: %s", ip);
00292     }
00293     return true;
00294 }
00295 
00296 
00297 void Wifly::flush()
00298 {
00299     buf_wifly.flush();
00300 }
00301 
00302 bool Wifly::sendCommand(const char * cmd, const char * ack, char * res, int timeout)
00303 {
00304     if (!state.cmd_mode) {
00305         cmdMode();
00306     }
00307     if (send(cmd, strlen(cmd), ack, res, timeout) == -1) {
00308         ERR("sendCommand: cannot %s\r\n", cmd);
00309         exit();
00310         return false;
00311     }
00312     return true;
00313 }
00314 
00315 bool Wifly::cmdMode()
00316 {
00317     // if already in cmd mode, return
00318     if (state.cmd_mode)
00319         return true;
00320 
00321     if (send("$$$", 3, "CMD") == -1) {
00322         ERR("cannot enter in cmd mode\r\n");
00323         exit();
00324         return false;
00325     }
00326     state.cmd_mode = true;
00327     return true;
00328 }
00329 
00330 bool Wifly::disconnect()
00331 {
00332     // if already disconnected, return
00333     if (!state.associated)
00334         return true;
00335 
00336     if (!sendCommand("leave\r", "DeAuth"))
00337         return false;
00338     exit();
00339 
00340     state.associated = false;
00341     return true;
00342 
00343 }
00344 
00345 bool Wifly::is_connected()
00346 {
00347     return (tcp_status.read() ==  1) ? true : false;
00348 }
00349 
00350 
00351 void Wifly::reset()
00352 {
00353     reset_pin = 0;
00354     wait(0.2);
00355     reset_pin = 1;
00356     wait(0.2);
00357 }
00358 
00359 bool Wifly::reboot()
00360 {
00361     // if already in cmd mode, return
00362     if (!sendCommand("reboot\r"))
00363         return false;
00364     
00365     wait(0.3);
00366 
00367     state.cmd_mode = false;
00368     return true;
00369 }
00370 
00371 bool Wifly::close()
00372 {
00373     // if not connected, return
00374     if (!state.tcp)
00375         return true;
00376 
00377     wait(0.25);
00378     if (!sendCommand("close\r", "CLOS"))
00379         return false;
00380     exit();
00381 
00382     state.tcp = false;
00383     return true;
00384 }
00385 
00386 
00387 int Wifly::putc(char c)
00388 {
00389     while (!wifi.writeable());
00390     return wifi.putc(c);
00391 }
00392 
00393 
00394 bool Wifly::exit()
00395 {
00396     flush();
00397     if (!state.cmd_mode)
00398         return true;
00399     if (!sendCommand("exit\r", "EXIT"))
00400         return false;
00401     state.cmd_mode = false;
00402     flush();
00403     return true;
00404 }
00405 
00406 
00407 int Wifly::readable()
00408 {
00409     return buf_wifly.available();
00410 }
00411 
00412 int Wifly::writeable()
00413 {
00414     return wifi.writeable();
00415 }
00416 
00417 char Wifly::getc()
00418 {
00419     char c;
00420     while (!buf_wifly.available());
00421     buf_wifly.dequeue(&c);
00422     return c;
00423 }
00424 
00425 void Wifly::handler_rx(void)
00426 {
00427     //read characters
00428     while (wifi.readable())
00429         buf_wifly.queue(wifi.getc());
00430 }
00431 
00432 void Wifly::attach_rx(bool callback)
00433 {
00434     if (!callback)
00435         wifi.attach(NULL);
00436     else
00437         wifi.attach(this, &Wifly::handler_rx);
00438 }
00439 
00440 
00441 int Wifly::send(const char * str, int len, const char * ACK, char * res, int timeout)
00442 {
00443     char read;
00444     size_t found = string::npos;
00445     string checking;
00446     Timer tmr;
00447     int result = 0;
00448 
00449     DBG("will send: %s\r\n",str);
00450 
00451     attach_rx(false);
00452 
00453     //We flush the buffer
00454     while (wifi.readable())
00455         wifi.getc();
00456 
00457     if (!ACK || !strcmp(ACK, "NO")) {
00458         for (int i = 0; i < len; i++)
00459             result = (putc(str[i]) == str[i]) ? result + 1 : result;
00460     } else {
00461         //We flush the buffer
00462         while (wifi.readable())
00463             wifi.getc();
00464 
00465         tmr.start();
00466         for (int i = 0; i < len; i++)
00467             result = (putc(str[i]) == str[i]) ? result + 1 : result;
00468 
00469         while (1) {
00470             if (tmr.read_ms() > timeout) {
00471                 //We flush the buffer
00472                 while (wifi.readable())
00473                     wifi.getc();
00474 
00475                 DBG("check: %s\r\n", checking.c_str());
00476 
00477                 attach_rx(true);
00478                 return -1;
00479             } else if (wifi.readable()) {
00480                 read = wifi.getc();
00481                 if ( read != '\r' && read != '\n') {
00482                     checking += read;
00483                     found = checking.find(ACK);
00484                     if (found != string::npos) {
00485                         wait(0.01);
00486 
00487                         //We flush the buffer
00488                         while (wifi.readable())
00489                             wifi.getc();
00490 
00491                         break;
00492                     }
00493                 }
00494             }
00495         }
00496         DBG("check: %s\r\n", checking.c_str());
00497 
00498         attach_rx(true);
00499         return result;
00500     }
00501 
00502     //the user wants the result from the command (ACK == NULL, res != NULL)
00503     if ( res != NULL) {
00504         int i = 0;
00505         Timer timeout;
00506         timeout.start();
00507         tmr.reset();
00508         while (1) {
00509             if (timeout.read() > 2) {
00510                 if (i == 0) {
00511                     res = NULL;
00512                     break;
00513                 }
00514                 res[i] = '\0';
00515                 DBG("user str 1: %s\r\n", res);
00516 
00517                 break;
00518             } else {
00519                 if (tmr.read_ms() > 300) {
00520                     res[i] = '\0';
00521                     DBG("user str: %s\r\n", res);
00522 
00523                     break;
00524                 }
00525                 if (wifi.readable()) {
00526                     tmr.start();
00527                     read = wifi.getc();
00528 
00529                     // we drop \r and \n
00530                     if ( read != '\r' && read != '\n') {
00531                         res[i++] = read;
00532                     }
00533                 }
00534             }
00535         }
00536         DBG("user str: %s\r\n", res);
00537     }
00538 
00539     //We flush the buffer
00540     while (wifi.readable())
00541         wifi.getc();
00542 
00543     attach_rx(true);
00544     DBG("result: %d\r\n", result)
00545     return result;
00546 }