Espressif ESP32-S2 User Manual

Chapter 2. API Reference
• service_type: (required) service type, prepended with underscore. Some common types can be found
here.
• proto: (required) protocol that the service runs on, prepended with underscore. Example: _tcp or _udp
• port: (required) network port that the service runs on
• txt: {var, val} array of strings, used to define properties for your service
Example method to add a few services and different properties:
void add_mdns_services()
{
//add our services
mdns_service_add(NULL, "_http", "_tcp", 80, NULL, 0);
mdns_service_add(NULL, "_arduino", "_tcp", 3232, NULL, 0);
mdns_service_add(NULL, "_myservice", "_udp", 1234, NULL, 0);
//NOTE: services must be added before their properties can be set
//use custom instance for the web server
mdns_service_instance_name_set("_http", "_tcp", "Jhon's ESP32-S2 Web Server");
mdns_txt_item_t serviceTxtData[3] = {
{"board","{esp32s2}"},
{"u","user"},
{"p","password"}
};
//set txt data for service (will free and replace current data)
mdns_service_txt_set("_http", "_tcp", serviceTxtData, 3);
//change service port
mdns_service_port_set("_myservice", "_udp", 4321);
}
mDNS Query mDNS provides methods for browsing for services and resolving host’s IP/IPv6 addresses.
Results for services are returned as a linked list of mdns_result_t objects.
Example method to resolve host IPs:
void resolve_mdns_host(const char * host_name)
{
printf("Query A: %s.local", host_name);
struct ip4_addr addr;
addr.addr = 0;
esp_err_t err = mdns_query_a(host_name, 2000, &addr);
if(err){
if(err == ESP_ERR_NOT_FOUND){
printf("Host was not found!");
return;
}
printf("Query Failed");
return;
}
printf(IPSTR, IP2STR(&addr));
}
Example method to resolve local services:
static const char * if_str[] = {"STA", "AP", "ETH", "MAX"};
static const char * ip_protocol_str[] = {"V4", "V6", "MAX"};
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Espressif ESP32-S2 Specifications

General

Brand	Espressif
Model	ESP32-S2
Category	Single board computers
Language	English