main.cpp

00001 /* Pehr Hovey
00002    Tests with UDP for mBed
00003  */
00004 
00005 #include "mbed.h"
00006 #include "lwip/init.h"
00007 #include "lwip/opt.h"
00008 #include "lwip/udp.h"
00009 
00010 
00011  
00012 #include "NetServer.h"
00013 
00014 #include "ipv4/lwip/ip_addr.h"
00015 
00016 int send_test = 0; //toggled by button
00017 
00018  struct udp_pcb *pcb;
00019 
00020 InterruptIn button(p8);
00021 
00022 DigitalOut got_udp(LED1);
00023 
00024 DigitalOut sent_udp(LED4);
00025 
00026 //callback for button interrupt
00027 void sendBroadcast(){
00028          //broadcast something
00029           struct pbuf *p;
00030         char msg[]="testing mBedUDP";
00031         p = pbuf_alloc(PBUF_TRANSPORT,sizeof(msg),PBUF_RAM);
00032         memcpy (p->payload, msg, sizeof(msg));
00033         err_t res = udp_sendto(pcb, p, IP_ADDR_BROADCAST, 5555); //broadcast test msg
00034         pbuf_free(p); //De-allocate packet buffer
00035         printf("Sent test message to port 1234, result is %d Waiting...\r\n",res);
00036 }
00037 
00038 //Send arbitrary data
00039 static void udp_send_something(char msg[], struct udp_pcb *upcb, struct ip_addr *addr, u16_t port)
00040 {
00041     printf("Sending message to port %d: %s\r\n",port,msg);
00042     sent_udp = 1;
00043     int psize = 40; //pick a size for now...
00044       struct pbuf *q;
00045         q = pbuf_alloc(PBUF_TRANSPORT,psize, PBUF_RAM);
00046       printf("Making packet with size %d\r\n",psize);
00047      if (q != NULL) {
00048         sent_udp = 1;
00049             q->payload = msg; //Assign the string pointer
00050           
00051             err_t code;
00052             /* send UDP response to IP addr and port specified */
00053           code = udp_sendto(upcb, q, IP_ADDR_BROADCAST, port);
00054             printf("Sent, result code is %d\r\n",code);
00055             /* free the "reference" pbuf */
00056             pbuf_free(q);
00057       }else{
00058       printf("Could not allocate packet buffer!\r\n");
00059       }
00060     sent_udp = 0;
00061 }
00062 
00063 /**UDP recv callback */
00064 static void udp_test_recv(void *arg, struct udp_pcb *upcb, struct pbuf *p, struct ip_addr *addr, u16_t port)
00065 {
00066    printf("Received UDP Packet on port %d\r\n",port);
00067   // printf("Received UDP Packet from ip_addr %s\r\n",  inet_ntoa(*(struct in_addr*)&(ip_addr)));
00068   LWIP_UNUSED_ARG(arg);
00069    got_udp = 1;
00070   /* if packet is valid */
00071   if (p != NULL) {
00072     //Try to print out what we received
00073     printf("UDP Packet Received! Payload:\r\n");
00074     printf("-- %s --\r\n",static_cast<char *>(p->payload));
00075    err_t code = udp_sendto(upcb, p, IP_ADDR_BROADCAST, 5555); //send it back to port 5555
00076      printf("Echo'd packet, result code is %d\r\n",code);
00077 
00078     
00079     /* free the pbuf */
00080     pbuf_free(p);
00081     got_udp=0;
00082     sent_udp=0;
00083   }
00084 }
00085 
00086 
00087 int main() {
00088   //Attach interrupt to the button to send packet on press
00089   button.rise(&sendBroadcast);
00090   
00091    /*Initialize NetServer which gets us our DHCP address and
00092     gets the network interface ready
00093     */
00094    NetServer *net = NetServer::ready();
00095   
00096  
00097    //Initialize UDP
00098  
00099     pcb = udp_new();
00100    
00101    
00102     
00103   if (pcb != NULL) {
00104     /* we have to be allowed to send broadcast packets! */
00105     pcb->so_options |= SOF_BROADCAST;
00106     udp_bind(pcb, IP_ADDR_ANY, 4444); //Receive from any IP address, on the specified port
00107     udp_recv(pcb,udp_test_recv, NULL);
00108   }else{
00109   printf("Could not make UDP pcb\r\n");
00110   }
00111    
00112   
00113  net->waitUntilReady(); //this will print IP
00114  net->setHostname("chapala");
00115    
00116    //Send a startup packet
00117     printf("UDP Tester started...\r\n");
00118     
00119     while(1) {
00120         net->poll();
00121         
00122     
00123     }
00124 }