Espressif Systems ESP User Manual

3.9.3 Can Wi-Fi be used with ESP-NOW at the same time? . . . . . . . . . . . . . . . . . . . 35
3.9.4 How do I set the rate at which ESP-NOW data is sent? . . . . . . . . . . . . . . . . . . . 35
3.9.5 ESP-NOW allows pairing with a maximum of 20 devices. Is there a way to control more
devices? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.9.6 What is the maximum number of devices that can be controlled by ESP-NOW? . . . . . . 35
3.9.7 Do I need to connect a router for communication between ESP-NOW devices? . . . . . . 36
3.9.8 Why does ESP-NOW limit the data length of each packet to 250 bytes? Can it be con󰝘gured? 36
3.9.9 What should I pay attention to when using ESP-NOW applications? . . . . . . . . . . . . 36
3.9.10 How can I reduce power consumption when using ESP-NOW? . . . . . . . . . . . . . . . 36
3.9.11 In addition to wireless communication through ESP-NOW, is there any other better way to
realize one-to-one and one-to-many communication? . . . . . . . . . . . . . . . . . . . . 36
3.9.12 Do ESP-NOW applications support sending packets over each Wi-Fi channel? . . . . . . 37
3.9.13 Are there any special procedures required if I intend to use ESP-NOW for commercial
purposes? Could you provide technical documentation on ESP-NOW? To evaluate the
quality of wireless communication, I would like to know relevant information about pa-
rameters including CSMA/CA, modulation method, and bit rate. . . . . . . . . . . . . . . 37
3.9.14 I tested the application esp-idf/examples/wi󰝘/espnow using ESP32. Does it only support
connecting to 7 encrypted devices at the maximum?
. . . . . . . . . . . . . . . . . . . . 37
3.10 ESP RainMaker cloud service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.11 ios application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.12 Third party cloud service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.12.1 Are there any examples for OTA upgrading? . . . . . . . . . . . . . . . . . . . . . . . . 37
3.12.2 Does ESP Azure library support Azure IoT Central? Is there an example? . . . . . . . . . 38
3.12.3 What should I do to connect ESP32 to Alibaba Cloud via ESP32 + Ethernet + MQTT? . . 38
3.12.4 what do Alexa LED states indicate? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.13 ESP-WIFI-MESH development framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.13.1 What is the maximum data transmission load for Wi-Fi mesh? . . . . . . . . . . . . . . . 38
3.13.2 Does ESP32’s Wi-Fi Mesh supports No Router self-networking? . . . . . . . . . . . . 38
3.13.3 What is the maximum number of node layers allowed when ESP32 uses Wi-Fi Mesh? . . 38
3.13.4 When using an ESP32 development board to test the esp-
mdf/examples/function_demo/mwi󰝘/router example, After ESP32 is connected to
the router, the device name in connection is “espressif”. How to modify this name? . . 39
3.13.5 Can Wi-Fi Mesh send messages to speci󰝘c nodes via TCP Server? . . . . . . . . . . . . . 39
3.13.6 During the operation of the ESP32 Wi-Fi Mesh network, if the Root node is lost, what
events will the system report back? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.13.7 I’m using ESP32 for Wi-Fi Mesh application with the esp_mesh_send() function,
but the server did not receive any data. How to transfer data from leaf nodes to external
servers? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.13.8 How do I upgrade my ESP-MESH device via OTA after networking? . . . . . . . . . . . 39
3.13.9 Can you provide ESP-MESH light reference design? . . . . . . . . . . . . . . . . . . . . 39
3.13.10 What is the default mode for ESP-MESH nodes without any con󰝘guration? . . . . . . . . 40
3.13.11 ESP-MESH starts with AP+STA mode enabled, can the phone search for APs? . . . . . . 40
3.13.12 Do I need to rescan for all the newly added devices when the original device has already
been networked? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.13.13 When using an ESP32 as a master device to synchronize time for multiple slave devices,
can the time error be less than 2 ms? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.13.14 How do I get the type of the node in ESP-MESH? . . . . . . . . . . . . . . . . . . . . . 40
3.13.15 Is there any demo of ESP-Mesh root node sending messages to a service via ethernet? . . 40
3.13.16 Does the esp-mesh-lite solution support the applications without routers? . . . . . . . . . 40
3.13.17 When esp-wifi-mesh is already networked, does the root or node device can also
enable Wi-Fi Scan to scan surrounding available AP information? . . . . . . . . . . . . . 41
3.13.18 How can I switch to a new router for networking when using the esp-wifi-mesh
router solution? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4 Software framework 43
4.1 Bluetooth LE & Bluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.1.1 When porting example gatt_server, an error occurred indicating head 󰝘le does not exist.
What could be the reasons? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
v

Espressif Systems ESP Specifications

General

Brand	Espressif Systems
Model	ESP
Category	Motherboard
Language	English