Espressif ESP32-S2 User Manual

Chapter 4. API Guides
7. Wi-Fi IP Change Phase
• s7.1: If the IP address is changed, the IP_EVENT_STA_GOT_IP will arise with “ip_change”set to true.
• s7.2: This event is important to the application. When it occurs, the timing is good for closing all
created sockets and recreating them.
8. Wi-Fi Deinit Phase
• s8.1: Call esp_wifi_disconnect() to disconnect the Wi-Fi connectivity.
• s8.2: Call esp_wifi_stop() to stop the Wi-Fi driver.
• s8.3: Call esp_wifi_deinit() to unload the Wi-Fi driver.
4.33.8 ESP32-S2 Wi-Fi AP General Scenario
Below is a “big scenario”which describes some small scenarios in AP mode:
4.33.9 ESP32-S2 Wi-Fi Scan
Currently, the esp_wifi_scan_start() API is supported only in Station or Station+AP mode.
Scan Type
Mode Description
Active Scan Scan by sending a probe request. The default scan is an
active scan.
Passive Scan No probe request is sent out. Just switch to the specific
channel and wait for a beacon. Application can enable
it via the scan_type field of wifi_scan_config_t.
Foreground Scan This scan is applicable when there is no Wi-Fi connec-
tion in Station mode. Foreground or background scan-
ning is controlled by the Wi-Fi driver and cannot be
configured by the application.
Background Scan This scan is applicable when there is a Wi-Fi connec-
tion in Station mode or in Station+AP mode. Whether
it is a foreground scan or background scan depends on
the Wi-Fi driver and cannot be configured by the appli-
cation.
All-Channel Scan It scans all of the channels. If the channel field of
wifi_scan_config_t is set to 0, it is an all-channel scan.
Specific Channel Scan
It scans specific channels only. If the channel field of
wifi_scan_config_t set to 1, it is a specific-channel scan.
The scan modes in above table can be combined arbitrarily, so we totally have 8 different scans:
• All-Channel Background Active Scan
• All-Channel Background Passive Scan
• All-Channel Foreground Active Scan
• All-Channel Foreground Passive Scan
• Specific-Channel Background Active Scan
• Specific-Channel Background Passive Scan
• Specific-Channel Foreground Active Scan
• Specific-Channel Foreground Passive Scan
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Release v4.4

Espressif ESP32-S2 Specifications

General

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