Espressif ESP32-S2 User Manual

Chapter 2. API Reference
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cfg.channel = CONFIG_MESH_CHANNEL;
/* router */
cfg.router.ssid_len = strlen(CONFIG_MESH_ROUTER_SSID);
memcpy((uint8_t *) &cfg.router.ssid, CONFIG_MESH_ROUTER_SSID, cfg.router.ssid_len);
memcpy((uint8_t *) &cfg.router.password, CONFIG_MESH_ROUTER_PASSWD,
strlen(CONFIG_MESH_ROUTER_PASSWD));
/* mesh softAP */
cfg.mesh_ap.max_connection = CONFIG_MESH_AP_CONNECTIONS;
memcpy((uint8_t *) &cfg.mesh_ap.password, CONFIG_MESH_AP_PASSWD,
strlen(CONFIG_MESH_AP_PASSWD));
ESP_ERROR_CHECK(esp_mesh_set_config(&cfg));
Start Mesh The following code snippet demonstrates how to start ESP-WIFI-MESH.
/* mesh start */
ESP_ERROR_CHECK(esp_mesh_start());
After starting ESP-WIFI-MESH, the application should check for ESP-WIFI-MESH events to determine when it
has connected to the network. After connecting, the application can start transmitting and receiving packets over the
ESP-WIFI-MESH network using esp_mesh_send() and esp_mesh_recv().
Self Organized Networking Self organized networking is a feature of ESP-WIFI-MESH where nodes can au-
tonomously scan/select/connect/reconnect to other nodes and routers. This feature allows an ESP-WIFI-MESH net-
work to operate with high degree of autonomy by making the network robust to dynamic network topologies and
conditions. With self organized networking enabled, nodes in an ESP-WIFI-MESH network are able to carry out the
following actions without autonomously:
• Selection or election of the root node (see Automatic Root Node Selection in Building a Network)
• Selection of a preferred parent node (see Parent Node Selection in Building a Network)
• Automatic reconnection upon detecting a disconnection (see Intermediate Parent Node Failure in Managing
a Network)
When self organized networking is enabled, the ESP-WIFI-MESH stack will internally make calls to Wi-Fi APIs.
Therefore, the application layer should not make any calls to Wi-Fi APIs whilst self organized networking is
enabled as doing so would risk interfering with ESP-WIFI-MESH.
Toggling Self Organized Networking Self organized networking can be enabled or disabled by the application
at runtime by calling the esp_mesh_set_self_organized() function. The function has the two following
parameters:
• bool enable specifies whether to enable or disable self organized networking.
• bool select_parent specifies whether a new parent node should be selected when enabling self orga-
nized networking. Selecting a new parent has different effects depending the node type and the node’s current
state. This parameter is unused when disabling self organized networking.
Disabling Self Organized Networking The following code snippet demonstrates how to disable self organized
networking.
//Disable self organized networking
esp_mesh_set_self_organized(false, false);
ESP-WIFI-MESH will attempt to maintain the node’s current Wi-Fi state when disabling self organized networking.
• If the node was previously connected to other nodes, it will remain connected.
• If the node was previously disconnected and was scanning for a parent node or router, it will stop scanning.
• If the node was previously attempting to reconnect to a parent node or router, it will stop reconnecting.
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Espressif ESP32-S2 Specifications

General

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