esp-idf/examples/bluetooth/bluedroid/ble/gattc_multi_connect/README.md

Supported Targets	ESP32	ESP32-C3	ESP32-C2	ESP32-H2

ESP-IDF Gatt Client Multi Connection Example

This example shows the usage of APIs to create a GATT multi-connection client. It can be used to connect to three GATT servers at the same time.

To test this example, please run gatt_server_demo to create three GATT server devices, namely ESP_GATTS_DEMO_a, ESP_GATTS_DEMO_b and ESP_GATTS_DEMO_c, Gatt_client_multi_connection_demo will connect to these three gatt server demos, and then exchange data.

Please, check this tutorial for more information about this example.

How to Use Example

Before project configuration and build, be sure to set the correct chip target using:

idf.py set-target <chip_name>

The code can be modified to connect to more devices (up to 4 devices by default). If you need to connect to more devices (more than 4 devices), you need to change BT/BLE MAX ACL CONNECTIONS in menuconfig.

Hardware Required

• A development board with ESP32/ESP32-C3/ESP32-C2/ESP32-H2 SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
• A USB cable for Power supply and programming

See Development Boards for more information about it.

Build and Flash

Run idf.py -p PORT flash monitor to build, flash and monitor the project.

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

I (0) cpu_start: Starting scheduler on APP CPU.
I (512) BTDM_INIT: BT controller compile version [1342a48]
I (522) system_api: Base MAC address is not set
I (522) system_api: read default base MAC address from EFUSE
I (522) phy_init: phy_version 4670,719f9f6,Feb 18 2021,17:07:07
I (932) GATTC_MULTIPLE_DEMO: REG_EVT
I (932) GATTC_MULTIPLE_DEMO: REG_EVT
I (932) GATTC_MULTIPLE_DEMO: REG_EVT
I (942) GATTC_MULTIPLE_DEMO: Scan start success
I (1072) GATTC_MULTIPLE_DEMO: 38 68 a4 69 bb 7c 
I (1072) GATTC_MULTIPLE_DEMO: Searched Adv Data Len 28, Scan Response Len 0
I (1072) GATTC_MULTIPLE_DEMO: Searched Device Name Len 0
I (1082) GATTC_MULTIPLE_DEMO: 

I (1102) GATTC_MULTIPLE_DEMO: 08 ef 3b a7 04 41 
I (1102) GATTC_MULTIPLE_DEMO: Searched Adv Data Len 9, Scan Response Len 15
I (1102) GATTC_MULTIPLE_DEMO: Searched Device Name Len 13
I (1112) GATTC_MULTIPLE_DEMO: LG CM2760(41)
I (1112) GATTC_MULTIPLE_DEMO: 

I (1222) GATTC_MULTIPLE_DEMO: 38 68 a4 69 bb 7c 
I (1222) GATTC_MULTIPLE_DEMO: Searched Adv Data Len 28, Scan Response Len 0
I (1222) GATTC_MULTIPLE_DEMO: Searched Device Name Len 0
I (1232) GATTC_MULTIPLE_DEMO: 

I (1372) GATTC_MULTIPLE_DEMO: 38 68 a4 69 bb 7c 
I (1372) GATTC_MULTIPLE_DEMO: Searched Adv Data Len 28, Scan Response Len 0
I (1372) GATTC_MULTIPLE_DEMO: Searched Device Name Len 0
I (1382) GATTC_MULTIPLE_DEMO: 

I (1412) GATTC_MULTIPLE_DEMO: 08 ef 3b a7 04 41 
I (1412) GATTC_MULTIPLE_DEMO: Searched Adv Data Len 9, Scan Response Len 15
I (1422) GATTC_MULTIPLE_DEMO: Searched Device Name Len 13
I (1422) GATTC_MULTIPLE_DEMO: LG CM2760(41)
I (1432) GATTC_MULTIPLE_DEMO: 

I (1522) GATTC_MULTIPLE_DEMO: 38 68 a4 69 bb 7c 
I (1522) GATTC_MULTIPLE_DEMO: Searched Adv Data Len 28, Scan Response Len 0
I (1522) GATTC_MULTIPLE_DEMO: Searched Device Name Len 0
I (1532) GATTC_MULTIPLE_DEMO:

Troubleshooting

For any technical queries, please open an issue on GitHub. We will get back to you soon.