Page 8 of 11
Chapter 7
Page 157 Simple UDP server
#include <stdio.h>
#include "pico/stdlib.h"
#include "pico/cyw43_arch.h"
#include "lwip/pbuf.h"
#include "lwip/udp.h"
#include "setupWifi.h"
int main()
{
stdio_init_all();
connect();
struct udp_pcb *pcb = udp_new();
udp_bind(pcb, IP_ADDR_ANY, 8080);
ip_addr_t ip;
IP4_ADDR(&ip, 192, 168, 11, 101);
udp_connect(pcb, &ip, 8080);
char message[] = "Hello UDP World";
struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, strlen(message) + 1, PBUF_RAM);
snprintf(p->payload, strlen(message) + 1, "%s", message);
err_t er = udp_send(pcb, p);
pbuf_free(p);
while (true)
{
sleep_ms(500);
}
}
Page 157 Full listing not in book
Simple UDP server lwipopts.h
#ifndef _LWIPOPTS_EXAMPLE_COMMONH_H
#define _LWIPOPTS_EXAMPLE_COMMONH_H
// Common settings used in most of the pico_w examples
// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html for details)
// allow override in some examples
#ifndef NO_SYS
#define NO_SYS 1
#endif
// allow override in some examples
#ifndef LWIP_SOCKET
#define LWIP_SOCKET 0
#endif
#if PICO_CYW43_ARCH_POLL
#define MEM_LIBC_MALLOC 1
#else
// MEM_LIBC_MALLOC is incompatible with non polling versions
#define MEM_LIBC_MALLOC 0
#endif
#define MEM_ALIGNMENT 4
#define MEM_SIZE 4000
#define MEMP_NUM_TCP_SEG 32
#define MEMP_NUM_ARP_QUEUE 10
#define PBUF_POOL_SIZE 24
#define LWIP_ARP 1
#define LWIP_ETHERNET 1
#define LWIP_ICMP 1
#define LWIP_RAW 1
#define TCP_WND (8 * TCP_MSS)
#define TCP_MSS 1460
#define TCP_SND_BUF (8 * TCP_MSS)
#define TCP_SND_QUEUELEN ((4 * (TCP_SND_BUF) + (TCP_MSS - 1)) / (TCP_MSS))
#define LWIP_NETIF_STATUS_CALLBACK 1
#define LWIP_NETIF_LINK_CALLBACK 1
#define LWIP_NETIF_HOSTNAME 1
#define LWIP_NETCONN 0
#define MEM_STATS 0
#define SYS_STATS 0
#define MEMP_STATS 0
#define LINK_STATS 0
// #define ETH_PAD_SIZE 2
#define LWIP_CHKSUM_ALGORITHM 3
#define LWIP_DHCP 1
#define LWIP_IPV4 1
#define LWIP_TCP 1
#define LWIP_UDP 1
#define LWIP_DNS 1
#define LWIP_TCP_KEEPALIVE 1
#define LWIP_NETIF_TX_SINGLE_PBUF 1
#define DHCP_DOES_ARP_CHECK 0
#define LWIP_DHCP_DOES_ACD_CHECK 0
#ifndef NDEBUG
#define LWIP_DEBUG 1
#define LWIP_STATS 1
#define LWIP_STATS_DISPLAY 1
#endif
#define ETHARP_DEBUG LWIP_DBG_OFF
#define NETIF_DEBUG LWIP_DBG_OFF
#define PBUF_DEBUG LWIP_DBG_OFF
#define API_LIB_DEBUG LWIP_DBG_OFF
#define API_MSG_DEBUG LWIP_DBG_OFF
#define SOCKETS_DEBUG LWIP_DBG_OFF
#define ICMP_DEBUG LWIP_DBG_OFF
#define INET_DEBUG LWIP_DBG_OFF
#define IP_DEBUG LWIP_DBG_OFF
#define IP_REASS_DEBUG LWIP_DBG_OFF
#define RAW_DEBUG LWIP_DBG_OFF
#define MEM_DEBUG LWIP_DBG_OFF
#define MEMP_DEBUG LWIP_DBG_OFF
#define SYS_DEBUG LWIP_DBG_OFF
#define TCP_DEBUG LWIP_DBG_OFF
#define TCP_INPUT_DEBUG LWIP_DBG_OFF
#define TCP_OUTPUT_DEBUG LWIP_DBG_OFF
#define TCP_RTO_DEBUG LWIP_DBG_OFF
#define TCP_CWND_DEBUG LWIP_DBG_OFF
#define TCP_WND_DEBUG LWIP_DBG_OFF
#define TCP_FR_DEBUG LWIP_DBG_OFF
#define TCP_QLEN_DEBUG LWIP_DBG_OFF
#define TCP_RST_DEBUG LWIP_DBG_OFF
#define UDP_DEBUG LWIP_DBG_OFF
#define TCPIP_DEBUG LWIP_DBG_OFF
#define PPP_DEBUG LWIP_DBG_OFF
#define SLIP_DEBUG LWIP_DBG_OFF
#define DHCP_DEBUG LWIP_DBG_OFF
#undef TCP_WND
#define TCP_WND 16384
#define LWIP_DEBUG 1
#endif /* __LWIPOPTS_H__ */
Page 158 Full listing not in book
Simple UDP server Cmakelists.txt
cmake_minimum_required(VERSION 3.13)
set(PICO_BOARD pico_w)
set(CMAKE_C_STANDARD 11)
set(CMAKE_CXX_STANDARD 17)
include(pico_sdk_import.cmake)
project(PicoW C CXX ASM)
pico_sdk_init()
add_executable(main
main.c
)
target_include_directories(main PRIVATE ${CMAKE_CURRENT_LIST_DIR})
target_link_libraries(main pico_stdlib pico_cyw43_arch_lwip_threadsafe_background)
pico_add_extra_outputs(main)
Page 158 Python UDP Client
import asyncio
class ClientDatagramProtocol(asyncio.DatagramProtocol):
def datagram_received(self, data, addr):
message = data.decode("utf8")
print("Received",message,"from", addr)
async def main():
loop = asyncio.get_running_loop()
transport, protocol = await loop.create_datagram_endpoint(
lambda: ClientDatagramProtocol(),
local_addr=('0.0.0.0', 8080))
await asyncio.sleep(100000)
transport.close()
asyncio.run(main())
Page 161 Full listing not in book
Simple UDP client
#include <stdio.h>
#include "pico/stdlib.h"
#include "pico/cyw43_arch.h"
#include "lwip/pbuf.h"
#include "lwip/udp.h"
#include "setupWifi.h"
#define BUF_SIZE 1024
void recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
{
char myBuff[BUF_SIZE];
if (p != NULL)
{
printf("recv total %d this buffer %d next %d \n", p->tot_len, p->len, p->next);
printf("From %s:%d\n", ipaddr_ntoa(addr), port);
pbuf_copy_partial(p, myBuff, p->tot_len, 0);
myBuff[p->tot_len] = 0;
printf("Buffer= %s\n", myBuff);
pbuf_free(p);
}
}
int main()
{
stdio_init_all();
connect();
struct udp_pcb *pcb = udp_new();
udp_recv(pcb, recv, NULL);
udp_bind(pcb, IP_ADDR_ANY, 8080);
// ip_addr_t ip;
// IP4_ADDR(&ip, 192, 168, 11, 101);
// IP4_ADDR(&ip, 192, 168, 11, 255);
// udp_connect(pcb, &ip, 8080);
while (true)
{
sleep_ms(500);
}
}
Page 162 Python UDP Server
import asyncio
async def main():
loop = asyncio.get_running_loop()
transport, protocol = await loop.create_datagram_endpoint(
lambda: asyncio.DatagramProtocol(),
local_addr=('0.0.0.0',8080))
data=b"Hello UDP World"
for i in range(20):
transport.sendto(data,addr=("192.168.11.255",8080))
await asyncio.sleep(1)
transport.close()
asyncio.run(main())
