Espressif ESP32-S2 User Manual

Chapter 2. API Reference
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.mode = 0,
.clock_speed_hz = CONFIG_EXAMPLE_ETH_SPI_CLOCK_MHZ * 1000 * 1000,
.spics_io_num = CONFIG_EXAMPLE_ETH_SPI_CS_GPIO,
.queue_size = 20
};
ESP_ERROR_CHECK(spi_bus_add_device(CONFIG_EXAMPLE_ETH_SPI_HOST, &devcfg, &spi_
,→handle));
/* dm9051 ethernet driver is based on spi driver */
eth_dm9051_config_t dm9051_config = ETH_DM9051_DEFAULT_CONFIG(spi_handle);
dm9051_config.int_gpio_num = CONFIG_EXAMPLE_ETH_SPI_INT_GPIO;
esp_eth_mac_t *mac = esp_eth_mac_new_dm9051(&dm9051_config, &mac_config);
esp_eth_phy_t *phy = esp_eth_phy_new_dm9051(&phy_config);
Note:
• When creating MAC and PHY instance for SPI-Ethernet modules (e.g. DM9051), the constructor function
must have the same suffix (e.g. esp_eth_mac_new_dm9051 and esp_eth_phy_new_dm9051). This is because
we don’t have other choices but the integrated PHY.
• We have to create an SPI device handle firstly and then pass it to the MAC constructor function. More instruc-
tions on creating SPI device handle, please refer to SPI Master.
• The SPI device configuration (i.e. spi_device_interface_config_t) can be different for other Ethernet modules.
Please check out your module’s spec and the examples in esp-idf.
Install Driver To install the Ethernet driver, we need to combine the instance of MAC and PHY and set some
additional high-level configurations (i.e. not specific to either MAC or PHY) in esp_eth_config_t:
• mac: instance that created from MAC generator (e.g. esp_eth_mac_new_esp32()).
• phy: instance that created from PHY generator (e.g. esp_eth_phy_new_ip101()).
• check_link_period_ms: Ethernet driver starts an OS timer to check the link status periodically, this
field is used to set the interval, in milliseconds.
• stack_input: In most of Ethernet IoT applications, any Ethernet frame that received by driver
should be passed to upper layer (e.g. TCP/IP stack). This field is set to a function which is re-
sponsible to deal with the incoming frames. You can even update this field at runtime via function
esp_eth_update_input_path() after driver installation.
• on_lowlevel_init_done and on_lowlevel_deinit_done: These two fields are used to specify
the hooks which get invoked when low level hardware has been initialized or de-initialized.
ESP-IDF provides a default configuration for driver installation in macro ETH_DEFAULT_CONFIG.
esp_eth_config_t config = ETH_DEFAULT_CONFIG(mac, phy); // apply default driver␣
,→configuration
esp_eth_handle_t eth_handle = NULL; // after driver installed, we will get the␣
,→handle of the driver
esp_eth_driver_install(&config, &eth_handle); // install driver
Ethernet driver also includes event-driven model, which will send useful and important event to user space. We need to
initialize the event loop before installing the Ethernet driver. For more information about event-driven programming,
please refer to ESP Event.
/** Event handler for Ethernet events */
static void eth_event_handler(void *arg, esp_event_base_t event_base,
int32_t event_id, void *event_data)
{
uint8_t mac_addr[6] = {0};
/* we can get the ethernet driver handle from event data */
esp_eth_handle_t eth_handle = *(esp_eth_handle_t *)event_data;
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Espressif ESP32-S2 Specifications

General

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