esp-idf/examples/cxx/experimental/esp_modem_cxx

Supported Targets	ESP32	ESP32-S2

Simple example of esp_modem component

(See the README.md file in the upper level 'examples' directory for more information about examples.)

Overview

This example demonstrates the use of the esp-modem component to connect to a network and send some AT commands. It uses modem CMUX mode so that commands and network could be used at the same time.

About the esp_modem

The esp_modem component is deployed automatically when building this example. It will be located inside this example directory, in relative path managed_components/espressif__esp_modem. You can find a brief introduction in the root directory of the component, in the main README.md for or a full html documentation in the relative path docs/html/index.html.

How to use example

Hardware Required

To run this example, you need an ESP32 dev board connected to a GSM/4G cellular module, which supports AT commands and PPP connectivity. The example uses UART to communicate with the modem and it uses the below pin assignment:

ESP32	Cellular Modem
GPIO25	RX
GPIO26	TX
GND	GND

Configure the project

• Choose the modem module in Choose supported modem device(DCE) option.
• Set the access point name in Set Access Point Name(APN) option, which should depend on the operator of your SIM card.
• Enable EXAMPLE_NEED_SIM_PIN: To unlock the SIM card with a PIN code if needed

Example Output

The example will unlock the SIM card (if enabled) and enter the CMUX mode. Then it would initiate the connection to a public MQTT broker and at the same time reading some data using AT commands.

I (571) uart: queue free spaces: 30
I (1731) cmux_example: Modem has correctly entered multiplexed command/data mode
I (2241) cmux_example: Operator name: "OperatorName"
I (7781) esp-netif_lwip-ppp: Connected
I (7781) esp-netif_lwip-ppp: Name Server1: xxx.xxx.xxx.xxx
I (7781) esp-netif_lwip-ppp: Name Server2: xxx.xxx.xxx.xxx
I (7781) cmux_example: Got IP address
I (7791) cmux_example: IP          : xxx.xxx.xxx.xxx
I (7791) cmux_example: Netmask     : xxx.xxx.xxx.xxx
I (7801) cmux_example: Gateway     : xxx.xxx.xxx.xxx
I (7801) system_api: Base MAC address is not set
I (7811) system_api: read default base MAC address from EFUSE
I (9061) cmux_example:  TOPIC: /topic/esp-modem
I (9061) cmux_example:  DATA: Hello modem
I (9061) cmux_example: Data received
I (9211) cmux_example: Modem IMSI number: xxxxxxxxxxxxxxxx
I (21221) esp-netif_lwip-ppp: User interrupt
I (21221) esp_modem_netif: PPP state changed event 5