ESP32 receive broadcast UDP packets

sensors
Posts: 1
Joined: Mon Feb 08, 2021 1:49 pm

ESP32 receive broadcast UDP packets

Postby sensors » Mon Feb 08, 2021 1:55 pm

Hello,

I'm attempting to configure a number of connected ESP32 stations using a single ESP32 AP. The easiest way for me to do this would be to send a single broadcast UDP packet to 255.255.255.255. However, my stations who are listening with an open UDP port are not receiving broadcast data at all. Is there something else I need to configure on the station/AP for this to be possible?

Here's my current station UDP listening task:

Code: Select all

static void udp_listen_task(void *pvParameters)
{

    while (1) {

        struct sockaddr_in dest_addr;
        dest_addr.sin_addr.s_addr = htonl(INADDR_ANY);
        dest_addr.sin_family = AF_INET;
        dest_addr.sin_port = htons(PORT);
        int addr_family = AF_INET;
        int ip_protocol = IPPROTO_IP;
        inet_ntoa_r(dest_addr.sin_addr, addr_str, sizeof(addr_str) - 1);


        int sock = socket(addr_family, SOCK_DGRAM, ip_protocol);
        if (sock < 0) {
            ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
            break;
        }
        //ESP_LOGI(TAG, "Socket created");

        int err = bind(sock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (err < 0) {
            ESP_LOGE(TAG, "Socket unable to bind: err %d", err);
        }

        while (1) {

            struct sockaddr_in6 source_addr; 
            socklen_t socklen = sizeof(source_addr);
            int len = recvfrom(sock, &controller_msg, sizeof(controller_msg), 0, (struct sockaddr *)&source_addr, &socklen);

            //Error occurred during receiving
            if (len < 0) {
                ESP_LOGE(TAG, "recvfrom failed: errno %d", errno);
                break;
            }
            // Data received
            else {

                // Get the sender's ip address as string
                if (source_addr.sin6_family == PF_INET) {
                    inet_ntoa_r(((struct sockaddr_in *)&source_addr)->sin_addr.s_addr, addr_str, sizeof(addr_str) - 1);
                } else if (source_addr.sin6_family == PF_INET6) {
                    inet6_ntoa_r(source_addr.sin6_addr, addr_str, sizeof(addr_str) - 1);
                }

                // Post event to act on message
                xEventGroupSetBits(conn_evt, CONN_EVT_UDP_RECEIVED);

            }
        }

        if (sock != -1) {
            ESP_LOGE(TAG, "Shutting down socket and restarting...");
            shutdown(sock, 0);
            close(sock);
        }
    }
    vTaskDelete(NULL);
}

Venketraj
Posts: 3
Joined: Wed Feb 03, 2021 11:25 am

Re: ESP32 receive broadcast UDP packets

Postby Venketraj » Fri Feb 12, 2021 11:13 am

can you post the full code to analyse it

Magnetuz
Posts: 12
Joined: Thu Dec 31, 2020 8:39 am

Re: ESP32 receive broadcast UDP packets

Postby Magnetuz » Tue Nov 23, 2021 9:34 am

Hello sensors,

I am having the same problem. Did you find a solution?

Regards.

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