Initial commit

basic-udp/main.c

@@ -0,0 +1,81 @@
+#include <string.h>
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+
+#include "lwip/netif.h"
+#include "lwip/udp.h"
+#include "lwip/pbuf.h"
+#include "lwip/ip_addr.h"
+#include "lwip/dhcp.h"
+
+#include "wifi-settings.h"
+
+static struct udp_pcb *udp;
+static ip_addr_t dest_ip;
+
+extern struct netif *netif_default;
+
+static void send_hello(void) {
+	const char msg[] = "hello world\n";
+
+	struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, sizeof(msg) - 1, PBUF_RAM);
+	if (!p) {
+		return;
+	}
+
+	memcpy(p->payload, msg, sizeof(msg) - 1);
+	udp_sendto(udp, p, &dest_ip, 5505);
+	pbuf_free(p);
+}
+
+int main() {
+	stdio_init_all();
+
+	if (cyw43_arch_init()) {
+		return -1;
+	}
+
+	cyw43_arch_enable_sta_mode();
+
+	if (cyw43_arch_wifi_connect_timeout_ms(
+			WIFI_SSID,
+			WIFI_PASS,
+			CYW43_AUTH_WPA2_AES_PSK,
+			30000)) {
+		return -1;
+	}
+
+	/* Raw lwIP setup */
+	udp = udp_new_ip_type(IPADDR_TYPE_V4);
+	if (!udp) {
+		return -1;
+	}
+
+	ipaddr_aton("192.168.2.99", &dest_ip);
+
+	absolute_time_t next = get_absolute_time();
+
+	bool dhcp_done = false;
+
+	while (true) {
+		cyw43_arch_poll();
+
+		if (!dhcp_done) {
+			if (netif_default &&
+				netif_is_up(netif_default) &&
+				!ip4_addr_isany_val(*netif_ip4_addr(netif_default))) {
+
+				dhcp_done = true;
+				cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
+			}
+		}
+
+		if (absolute_time_diff_us(get_absolute_time(), next) <= 0) {
+			send_hello();
+			next = delayed_by_ms(next, 1000);
+		}
+
+		sleep_ms(1);
+	}
+}