Espressif ESP32-S2 User Manual

Chapter 2. API Reference
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switch (event_id) {
case ETHERNET_EVENT_CONNECTED:
esp_eth_ioctl(eth_handle, ETH_CMD_G_MAC_ADDR, mac_addr);
ESP_LOGI(TAG, "Ethernet Link Up");
ESP_LOGI(TAG, "Ethernet HW Addr %02x:%02x:%02x:%02x:%02x:%02x",
mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_
,→addr[4], mac_addr[5]);
break;
case ETHERNET_EVENT_DISCONNECTED:
ESP_LOGI(TAG, "Ethernet Link Down");
break;
case ETHERNET_EVENT_START:
ESP_LOGI(TAG, "Ethernet Started");
break;
case ETHERNET_EVENT_STOP:
ESP_LOGI(TAG, "Ethernet Stopped");
break;
default:
break;
}
}
esp_event_loop_create_default(); // create a default event loop that running in␣
,→background
esp_event_handler_register(ETH_EVENT, ESP_EVENT_ANY_ID, &eth_event_handler, NULL);␣
,→// register Ethernet event handler (to deal with user specific stuffs when event␣
,→like link up/down happened)
Start Ethernet Driver After driver installation, we can start Ethernet immediately.
esp_eth_start(eth_handle); // start Ethernet driver state machine
Connect Driver to TCP/IP Stack Up until now, we have installed the Ethernet driver. From the view of OSI
(Open System Interconnection), we’re still on level 2 (i.e. Data Link Layer). We can detect link up and down event,
we can gain MAC address in user space, but we can’t obtain IP address, let alone send HTTP request. The TCP/IP
stack used in ESP-IDF is called LwIP, for more information about it, please refer to LwIP.
To connect Ethernet driver to TCP/IP stack, these three steps need to follow:
1. Create network interface for Ethernet driver
2. Attach the network interface to Ethernet driver
3. Register IP event handlers
More information about network interface, please refer to Network Interface.
/** Event handler for IP_EVENT_ETH_GOT_IP */
static void got_ip_event_handler(void *arg, esp_event_base_t event_base,
int32_t event_id, void *event_data)
{
ip_event_got_ip_t *event = (ip_event_got_ip_t *) event_data;
const esp_netif_ip_info_t *ip_info = &event->ip_info;
ESP_LOGI(TAG, "Ethernet Got IP Address");
ESP_LOGI(TAG, "~~~~~~~~~~~");
ESP_LOGI(TAG, "ETHIP:" IPSTR, IP2STR(&ip_info->ip));
ESP_LOGI(TAG, "ETHMASK:" IPSTR, IP2STR(&ip_info->netmask));
ESP_LOGI(TAG, "ETHGW:" IPSTR, IP2STR(&ip_info->gw));
ESP_LOGI(TAG, "~~~~~~~~~~~");
}
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Espressif Systems 174
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Release v4.4

Espressif ESP32-S2 Specifications

General

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