Add mDNS functionality

Closes #9

src/CMakeLists.txt

@@ -18,10 +18,17 @@ execute_process(COMMAND
         )
 file(RENAME fsdata.c my_fsdata.c)
 
+
+# TODO fix after https://github.com/georgerobotics/cyw43-driver/pull/39 gets into the SDK
+set(BROKEN_FILE ${PICO_CYW43_DRIVER_PATH}/src/cyw43_lwip.c)
+file(READ ${BROKEN_FILE} FILE_CONTENTS)
+string(REPLACE "LWIP_MDNS_RESPONDER" "LWIP_1_MDNS_RESPONDER" FILE_CONTENTS "${FILE_CONTENTS}")
+file(WRITE ${BROKEN_FILE} "${FILE_CONTENTS}")
+
 add_executable(${PROGRAM_NAME}
         main.cpp
         double_reset_detector.cpp
-        access_point.cpp
+        network_utils.cpp
         http_server.cpp
         )
 target_compile_definitions(${PROGRAM_NAME} PRIVATE
@@ -35,6 +42,7 @@ target_link_libraries(${PROGRAM_NAME}
         cyw43_driver_base
         pico_cyw43_arch_lwip_threadsafe_background
         pico_lwip_http
+        pico_lwip_mdns
         pico_stdlib
         hardware_adc
         )

src/lwipopts.h

@@ -57,6 +57,10 @@
 
 #define LWIP_AUTOIP 1
 
+#define LWIP_IGMP 1
+#define LWIP_MDNS_RESPONDER 1
+#define LWIP_NUM_NETIF_CLIENT_DATA (LWIP_MDNS_RESPONDER)
+
 #define LWIP_HTTPD 1
 #define LWIP_HTTPD_SSI 1
 // don't include the tag comment - less work for the CPU, but may be harder to debug

src/main.cpp

@@ -7,38 +7,14 @@
 
 #include "double_reset_detector.h"
 #include "http_server.h"
-#include "access_point.h"
+#include "network_utils.h"
 
 #include "lwipopts.h"
 
-namespace double_reset_detector {
-    extern bool double_reset_detected;
-}
-
-int connect_to_wifi() {
-     cyw43_arch_enable_sta_mode();
-    // this seems to be the best be can do using the predefined `cyw43_pm_value` macro:
-    // cyw43_wifi_pm(&cyw43_state, CYW43_PERFORMANCE_PM);
-    // however it doesn't use the `CYW43_NO_POWERSAVE_MODE` value, so we do this instead:
-    cyw43_wifi_pm(&cyw43_state, cyw43_pm_value(CYW43_NO_POWERSAVE_MODE, 20, 1, 1, 1));
-
-    printf("Connecting to WiFi...\n");
-    if (cyw43_arch_wifi_connect_timeout_ms(WIFI_SSID, WIFI_PASSWORD, CYW43_AUTH_WPA2_AES_PSK, 30000)) {
-        printf("failed to connect.\n");
-        return ERR_CONN;
-    } else {
-        printf("Connected.\n");
-
-        auto ip_addr = cyw43_state.netif[CYW43_ITF_STA].ip_addr.addr;
-        printf("IP Address: %lu.%lu.%lu.%lu\n", ip_addr & 0xFF, (ip_addr >> 8) & 0xFF, (ip_addr >> 16) & 0xFF, ip_addr >> 24);
-    }
-    return ERR_OK;
-}
-
 void setup() {
     if (double_reset_detector::double_reset_detected) {
         printf("Double reset detected!\n");
-        access_point::setup_access_point();
+        network_utils::setup_access_point();
         http_server::start_http_server();
         while (true) {
             cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
@@ -59,7 +35,7 @@ int main() {
     // turn on LED to distinguish from BOOTSEL mode
     cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
     setup();
-    if (connect_to_wifi() != ERR_OK) {
+    if (network_utils::connect_to_wifi() != ERR_OK) {
         return 1;
     }
     http_server::start_http_server();

src/network_utils.cpp

@@ -0,0 +1,88 @@
+#include "network_utils.h"
+
+extern "C" {
+#include <cyw43.h>
+}
+#include <lwip/autoip.h>
+#include <lwip/apps/mdns.h>
+#include <lwip/err.h>
+#include <pico/cyw43_arch.h>
+
+namespace network_utils {
+
+err_t setup_mdns(struct netif *netif){
+    const auto hostname =  "pico-w-webserver";
+    mdns_resp_init();
+    return mdns_resp_add_netif(netif, hostname);
+}
+
+err_t connect_to_wifi() {
+     cyw43_arch_enable_sta_mode();
+    // this seems to be the best be can do using the predefined `cyw43_pm_value` macro:
+    // cyw43_wifi_pm(&cyw43_state, CYW43_PERFORMANCE_PM);
+    // however it doesn't use the `CYW43_NO_POWERSAVE_MODE` value, so we do this instead:
+    cyw43_wifi_pm(&cyw43_state, cyw43_pm_value(CYW43_NO_POWERSAVE_MODE, 20, 1, 1, 1));
+    auto& netif = cyw43_state.netif[CYW43_ITF_STA];
+    const auto err = setup_mdns(&netif);
+    if (err != ERR_OK) {
+        return err;
+    }
+
+    printf("Connecting to WiFi...\n");
+    if (cyw43_arch_wifi_connect_timeout_ms(WIFI_SSID, WIFI_PASSWORD, CYW43_AUTH_WPA2_AES_PSK, 30000)) {
+        printf("failed to connect.\n");
+        return ERR_CONN;
+    } else {
+        printf("Connected.\n");
+
+        auto ip_addr = netif.ip_addr.addr;
+        printf("IP Address: %lu.%lu.%lu.%lu\n", ip_addr & 0xFF, (ip_addr >> 8) & 0xFF, (ip_addr >> 16) & 0xFF, ip_addr >> 24);
+    }
+    return ERR_OK;
+}
+
+err_t stop_access_point(){
+    auto& netif = cyw43_state.netif[CYW43_ITF_AP];
+    auto err = autoip_stop(&netif);
+    if (err != ERR_OK){
+        return err;
+    }
+    err = mdns_resp_remove_netif(&netif);
+    if (err != ERR_OK){
+        return err;
+    }
+    return ERR_OK;
+}
+
+err_t setup_access_point() {
+    if (!cyw43_is_initialized(&cyw43_state)){
+        if (cyw43_arch_init()) {
+            printf("failed to initialise\n");
+            return ERR_ABRT;
+        }
+    }
+
+    const char *ap_name = "picow_webserver";
+    const char *password = NULL;
+
+    cyw43_arch_enable_ap_mode(ap_name, password, CYW43_AUTH_WPA2_AES_PSK);
+    // sleep mostly to let serial monitor catch the ip log. probably to be removed once mDNS is set up
+    sleep_ms(2000);
+
+    auto& netif = cyw43_state.netif[CYW43_ITF_AP];
+    const auto err = setup_mdns(&netif);
+    if (err != ERR_OK) {
+        return err;
+    }
+
+    autoip_start(&netif);
+    auto link_local_ip_addr = netif_autoip_data(&netif)->llipaddr.addr;
+    printf("IP Address: %lu.%lu.%lu.%lu\n",
+        link_local_ip_addr & 0xFF,
+        (link_local_ip_addr >> 8) & 0xFF,
+        (link_local_ip_addr >> 16) & 0xFF,
+        link_local_ip_addr >> 24);
+    return ERR_OK;
+}
+
+} // namespace network_utils

src/network_utils.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <lwip/err.h>
+
+namespace network_utils {
+    err_t connect_to_wifi();
+
+    err_t stop_access_point();
+
+    err_t setup_access_point();
+} // namespace network_utils