Add example for wifi_settings_connect library

CMakeLists.txt

@@ -40,3 +40,4 @@ add_subdirectory(reset)
 add_subdirectory(scanvideo)
 add_subdirectory(sleep)
 add_subdirectory(stdio)
+add_subdirectory(wifi_settings_connect)

README.md

@@ -68,3 +68,11 @@ even though it is in the Pico SDK
 Name|Description
 ---|---
 [stdio_pio](stdio/pio)| Demonstrates adding a custom STDIO driver using a PIO UART
+
+## WiFi
+
+Example using the wifi\_settings\_connect library from pico\_extras.
+
+Name|Description
+---|---
+[wifi\_settings\_connect\_example](wifi_settings_connect/example)| Demonstrates connecting to WiFi hotspots and sending UDP broadcasts

wifi_settings_connect/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory(example)

wifi_settings_connect/example/CMakeLists.txt

@@ -0,0 +1,40 @@
+#
+# Copyright (c) 2025 Jack Whitham
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+# Example for wifi_settings_connect.
+#
+# This example connects to WiFi using wifi_settings_connect functions,
+# and then broadcasts a message on UDP port 1234 every second.
+# You can receive these with any tool that can receive
+# UDP, e.g. tcpdump, Wireshark, or netcat:
+#
+#   nc -l -u -p 1234
+#
+# The WiFi connection details must be configured in Flash as described here:
+# https://github.com/jwhitham/pico-wifi-settings/blob/master/doc/SETTINGS_FILE.md
+#
+
+# only build wifi_settings_connect example if library is available
+if (TARGET wifi_settings_connect)
+    # Build example with async_context tasks running in the background
+    # You can use pico_cyw43_arch_lwip_poll instead of
+    # pico_cyw43_arch_lwip_threadsafe_background to use polling, if you prefer.
+    add_executable(wifi_settings_connect_example
+            example.c
+        )
+    target_include_directories(wifi_settings_connect_example PRIVATE
+            ${CMAKE_CURRENT_LIST_DIR}
+        )
+    target_link_libraries(wifi_settings_connect_example
+            pico_cyw43_arch_lwip_threadsafe_background
+            wifi_settings_connect 
+            pico_stdlib
+        )
+
+    pico_enable_stdio_usb(wifi_settings_connect_example 1)
+    pico_enable_stdio_uart(wifi_settings_connect_example 0)
+
+    pico_add_extra_outputs(wifi_settings_connect_example)
+endif ()

wifi_settings_connect/example/README.md

@@ -0,0 +1,44 @@
+# wifi\_settings\_connect example
+
+Example using the wifi\_settings\_connect library to connect to a WiFi hotspot.
+
+The Flash storage location for hotspot details is specified in
+`include/wifi_settings/wifi_settings_configuration.h`. It is at
+`0x101fc000` (for Pico W) and `0x103fc000` (for Pico 2 W). This
+"wifi-settings file" is a text file which can be edited with any text editor.
+Here is an example of typical contents:
+```
+    ssid1=MyHomeWiFi
+    pass1=mypassword1234
+    ssid2=MyPhoneHotspot
+    pass2=secretpassword
+    country=GB
+```
+To add your WiFi details at this location, please [see the setup instructions in the pico-extras
+repo](https://github.com/raspberrypi/pico-extras/tree/master/src/rp2_common/wifi_settings_connect/doc/SETTINGS_FILE.md).
+
+To build this example, first run `cmake` at the top level of the
+`pico-playground` repository, specifying the locations for
+the `pico-sdk` and `pico-extras` repositories, e.g.:
+```
+    cd /home/user/pico-playground
+    mkdir build
+    cd build
+    cmake -DPICO_SDK_PATH=/home/user/pico-sdk \
+        -DPICO_EXTRAS_PATH=/home/user/pico-extras \
+        -DPICO_BOARD=pico_w ..
+```
+Then, run `make` within the `build/wifi_settings_connect/example`
+directory, e.g.
+```
+    cd /home/user/pico-playground
+    make -C build/wifi_settings_connect/example
+```
+This will create the UF2 file to be downloaded to the Pico
+in `build/wifi_settings_connect/example`.
+
+The example program will search for WiFi hotspots. If it finds a hotspot which
+matches those configured in Flash, then it will automatically
+connect to it and begin a UDP broadcast. The example program prints
+its status to the USB serial port; connect with a terminal program
+to see what it is doing.

wifi_settings_connect/example/example.c

@@ -0,0 +1,157 @@
+/**
+ * Copyright (c) 2025 Jack Whitham
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Example for wifi-settings.
+ *
+ * This example connects to WiFi using wifi_settings_connect functions,
+ * and then broadcasts a message on UDP port 1234 every second.
+ * You can receive these with any tool that can receive
+ * UDP, e.g. tcpdump, Wireshark, or netcat:
+ *
+ *   nc -l -u -p 1234
+ *
+ * The WiFi connection details must be configured in Flash as described here:
+ * https://github.com/jwhitham/pico-wifi-settings/blob/master/doc/SETTINGS_FILE.md
+ */
+
+
+#include <string.h>
+#include <time.h>
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include "pico/bootrom.h"
+
+#include "lwip/pbuf.h"
+#include "lwip/tcp.h"
+
+#include "wifi_settings/wifi_settings_connect.h"
+#include "wifi_settings/wifi_settings_hostname.h"
+
+
+bool send_udp_packet(uint count) {
+    // Send a UDP broadcast to port 1234
+    char text[256];
+    bool ok = false;
+
+    struct udp_pcb* udp_pcb = udp_new();
+    if (!udp_pcb) {
+        printf("Failed to allocate space for UDP PCB!\n");
+    } else {
+        snprintf(text, sizeof(text), "Hello World %u from %s\n", count, wifi_settings_get_hostname());
+        const uint size = strlen(text);
+        struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, size, PBUF_RAM);
+        if (!p) {
+            printf("Failed to allocate space for UDP packet!\n");
+        } else {
+            memcpy(p->payload, text, size);
+            ip_addr_t addr;
+            ipaddr_aton("255.255.255.255", &addr);
+            const err_t err = udp_sendto(udp_pcb, p, &addr, 1234);
+            if (err) {
+                printf("Failed to send UDP packet! error=%d\n", (int) err);
+            } else {
+                printf("UDP broadcast, port 1234: %s", text);
+                ok = true;
+            }
+            pbuf_free(p);
+        }
+        udp_remove(udp_pcb);
+    }
+    return ok;
+}
+
+int main() {
+    stdio_init_all();
+
+    // Initialise pico-wifi-settings
+    int rc = wifi_settings_init();
+    if (rc != 0) {
+        panic("wifi_settings_init() failed");
+        return 1;
+    }
+
+    // Begin connecting to WiFi (this function returns immediately)
+    wifi_settings_connect();
+
+    uint count = 0;
+    bool stay_in_loop = true;
+    while (stay_in_loop) {
+        // clear screen
+        printf("\x1b[2J\r");
+
+        // print host name and board ID
+        printf("Hostname = %s\n"
+               "Board ID = %s\n\n",
+               wifi_settings_get_hostname(),
+               wifi_settings_get_board_id_hex());
+        fflush(stdout);
+
+        // print connection status
+        char text[512];
+        wifi_settings_get_connect_status_text(text, sizeof(text));
+        printf("%s\n\n", text);
+        if (wifi_settings_has_no_wifi_details()) {
+            // Help the user if no SSIDs are configured
+            printf("You need to configure at least one hotspot! See\n"
+                   "https://github.com/jwhitham/pico-wifi-settings/blob/master/doc/SETTINGS_FILE.md\n"
+                   "for instructions.\n\n");
+        } else {
+            wifi_settings_get_hw_status_text(text, sizeof(text));
+            printf("%s\n", text);
+            wifi_settings_get_ip_status_text(text, sizeof(text));
+            printf("%s\n", text);
+        }
+        fflush(stdout);
+
+        // Send a UDP broadcast to port 1234 if connected
+        if (wifi_settings_is_connected()) {
+            if (send_udp_packet(count)) {
+                count++;
+            }
+        }
+
+        printf("press 'c' to connect, 'd' to disconnect, 'r' to return to bootloader\n");
+        fflush(stdout);
+        switch (getchar_timeout_us(1)) {
+            case 'c':
+                wifi_settings_connect();
+                break;
+            case 'd':
+                wifi_settings_disconnect();
+                break;
+            case 'r':
+                stay_in_loop = false;
+                break;
+            default:
+                break;
+        }
+#if PICO_CYW43_ARCH_POLL
+        // if you are using pico_cyw43_arch_poll, then you must poll periodically from your
+        // main loop (not from a timer interrupt) to check for wifi_settings, WiFi driver
+        // or lwIP work that needs to be done.
+        cyw43_arch_poll();
+        // you can poll as often as you like, however if you have nothing else to do you can
+        // choose to sleep:
+        sleep_ms(1000);
+#else
+        // if you are not using pico_cyw43_arch_poll, then wifi_settings, WiFI driver and lwIP work
+        // is done via interrupt in the background. This sleep is just an example of some (blocking)
+        // work you might be doing.
+        sleep_ms(1000);
+#endif
+    }
+    printf("That's all\n");
+
+    // Disconnection and de-initialisation are optional steps
+    // with wifi_settings, but you may wish to explicitly stop
+    // the WiFi connection for some reason:
+    wifi_settings_disconnect();
+    wifi_settings_deinit();
+    printf("Goodbye\n");
+    // return to boot loader
+    reset_usb_boot(0, 0);
+    return 0;
+}

wifi_settings_connect/example/lwipopts.h

@@ -0,0 +1,85 @@
+#ifndef _LWIPOPTS_H
+#define _LWIPOPTS_H
+
+
+// This example LWIP settings file has been adapted from the pico-examples repo.
+// See https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html for details.
+// Note: pico-wifi-settings has been tested with LWIP projects that use NO_SYS and
+// don't use LWIP_SOCKET - there has not yet been any attempt to support FreeRTOS.
+#define NO_SYS                      1
+#define LWIP_SOCKET                 0
+#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
+
+#endif /* __LWIPOPTS_H__ */