UDP Receive

Question

We are receiving data using the loopback_udp function shown in W5300_Drv_AVR_V1.2.2. If the amount of data sent from the PC is about 500 bytes, it will be received without any problem. If it exceeds 1KB, it will not be received. I do not go into the example source below if ((len = getSn_RX_RSR (s))> 0) conditional statement. Whether to increase buffer size … However, loopback_tcps seems to be receiving no problem, and it does not seem to be that … Please advise … T.T void loopback_udp(SOCKET s, uint16 port, uint8* buf, uint16 mode) { uint32 len; uint8 destip[4]; uint16 destport; switch(getSn_SSR(s)) { case SOCK_UDP: if ((len=getSn_RX_RSR(s)) > 0) { len = recvfrom(s,buf,len,destip,&destport); if (len !=sendto(s,buf,len,destip,destport)) { -------------------- } } break; case SOCK_CLOSED: close(s); socket(s,Sn_MR_UDP,port,mode); break; default: break; } }

Eugeny · Answer

What is the RX buffer size for the socket you use? With TCP network devices can negotiate buffer size, with UDP if packet does not fit into the buffer, I am afraid it will be discarded. Thus might be that you set RX buffer size to 1 KB. Increase buffer size and see.