Anjay ESP32 Client

Overview

This repository contains a LwM2M Client application example for ESP32 devices, based on open-source Anjay-esp-idf component and Espressif IoT Development Framework.

The following boards are supported natively in the project:

• ESP-WROVER-KIT
• ESP32-DevKitC
• M5StickC-Plus

You may also use other boards, by selecting the Unknown board and manually configuring available peripherals through Kconfig.

The following LwM2M Objects are supported:

Target	Objects
Common	Security (/0) Server (/1) Device (/3) Firmware Update (/5) WLAN connectivity (/12)
ESP-WROVER-KIT	Push button (/3347) Light control (/3311)
ESP32-DevKitC	Push button (/3347)
M5StickC-Plus	Push button (/3347) Light control (/3311) Temperature sensor (/3303) Accelerometer (/3313) Gyroscope (/3343)

Compiling and launching

1. Install ESP-IDF and its dependencies on your computer. Please follow the instructions at https://docs.espressif.com/projects/esp-idf/en/v5.3.1/esp32/get-started/index.html including Manual Installation up to the Start a Project subtitle.
   • The project has been tested with ESP-IDF v5.3.1, but may work with other v5.x.x versions as well. Older versions are not supported.
2. Clone the repository git clone https://github.com/AVSystem/Anjay-esp32-client.git and navigate to project directory
3. Initialize and update submodules with git submodule update --init --recursive
4. Run idf.py set-target esp32 in the project directory
5. Run idf.py menuconfig
   • navigate to Component config/anjay-esp32-client:
     • select one of supported boards or manually configure the board in Board options menu
     • configure LwM2M client configuration in Client options menu
     • configure Wi-Fi in Connection configuration menu
   • navigate to Component config/Anjay library configuration to configure Anjay library and its dependencies (avs_commons and avs_coap)
6. Run idf.py build to compile
7. Run idf.py flash to flash
   • NOTE: M5StickC-Plus does not support default baudrate, run idf.py -b 750000 flash to flash it
8. The logs will be on the same /dev/ttyUSB<n> port that the above used for flashing, 115200 8N1
   • You can use idf.py monitor to see logs on serial output from a connected device, or even more conveniently idf.py flash monitor as one command to see logs right after the device is flashed

Connecting to the LwM2M Server

To connect to Coiote IoT Device Management LwM2M Server, please register at https://eu.iot.avsystem.cloud/. The default Server URI (Kconfig option ANJAY_CLIENT_SERVER_URI) is set to EU Cloud Coiote DM instance, but you must manually set other client configuration options.

NOTE: You may use any LwM2M Server compliant with LwM2M 1.0 TS. The server URI can be changed in the example configuration options.

Connecting using NVS provided credentials

It is possible to use pre-built binaries to flash the board and provide credentials by flashing a NVS partition binary. To do that, esptool.py is required, which can be installed running pip install esptool

Creating a merged binary for M5StickC-Plus

esptool.py --chip esp32  merge_bin --flash_mode dio --flash_size 4MB --flash_freq 40m 0x1000 build/bootloader/bootloader.bin 0x8000 build/partition_table/partition-table.bin 0x10000 build/anjay-esp32-client.bin 0x310000 build/storage.bin --output m5stickc-plus.bin

NVS config file

To generate NVS partition, create a nvs_config.csv file with following content:

key,type,encoding,value
config,namespace,,
wifi_ssid,data,string,[wifi_ssid]
wifi_pswd,data,string,[wifi_password]
wifi_inter_en,data,u8,1
endpoint_name,data,string,[endpoint_name]
identity,data,string,[identity]
psk,data,string,[psk]
uri,data,string,[lwm2m_server_uri]
writable_wifi,namespace,,
wifi_ssid,data,string,[wifi_ssid]
wifi_pswd,data,string,[wifi_password]
wifi_inter_en,data,u8,0

And fill proper values for [wifi_ssid], [wifi_password], [endpoint_name], [identity], [psk], [lwm2m_server_uri]. After that create config partition by running:

python3 $IDF_PATH/components/nvs_flash/nvs_partition_generator/nvs_partition_gen.py generate nvs_config.csv nvs_config.bin 0x4000

Flashing the firmware and partitions

After partition is created, flash firmware and configuration using following commands (baudrate may vary depending on your board):

esptool.py -b 750000 --chip esp32 write_flash 0x0000 m5stickc-plus.bin
esptool.py -b 750000 --chip esp32 write_flash 0x9000 nvs_config.bin

Device will be reset and run with provided configuration.

TCP socket

To switch to TCP socket instead of UDP run idf.py menuconfig, navigate to Component config/anjay-esp32-client/Client options/Choose socket and select TCP (remember that you must also provide a proper URI in the nvs_config.csv file, e.g. coaps+tcp://eu.iot.avsystem.cloud:5684).

ESP32 with certificates

1. Prepare your certificates. All certificates should have a .der extension and should be added to the directory where this README.md file is located. The names of the certificates should be as follows:
   • client public certificate - client_cert.der
   • client private certificate - client_key.der
   • server public certificate - server_cert.der
2. Run idf.py menuconfig, navigate to Component config/anjay-esp32-client/Client options/Choose security mode and select Certificates.

FOTA

After compilation, you can perform FOTA with Coiote DM. Required binary file location:

$PROJECT_DIR/build/anjay-esp32-client/build/anjay-esp32-client.bin

ESP32 with BG96 and FreeRTOS cellular library

1. Prepare your BG96 module, connect it to the selected ESP32 UART interface.
2. Run idf.py menuconfig
   • navigate to Component config/anjay-esp32-client:
     • select External BG96 module in Choose an interface menu
   • navigate to Component config/Anjay library configuration/Enable support for external BG96 module:
     • configure BG96 in BG96 module configuration menu
     • configure PDN authentication type in PDN authentication type menu
     • configure the APN name (and PDN username/password if needed)

Links

• Anjay source repository
• Anjay documentation
• Doxygen-generated API documentation
• AVSystem IoT Devzone
• AVSystem Discord server
• FreeRTOS cellular library