v2.4.0.0 Release Notes

v2.4.0.0 is released for ESP32 and ESP32-C3. The changes since the previous version are as follows.

• ESP32-AT
• ESP32C3-AT

ESP32-AT

Documentation for Release v2.4.0.0 is available at https://docs.espressif.com/projects/esp-at/en/release-v2.4.0.0/esp32/index.html
ESP32-AT v2.4.0.0 is a major update for ESP32-AT v2.2.0.0.

This is the list of changes since release v2.2.0.0:

Breaking Changes

• esp-idf version updated to release v4.3 (588436db)
• BT A2DP: modified default I2S_DATA_PIN from GPIO33 to GPIO25 (due to pin conflicts with 32 kHz crystal oscillator when using BLE light sleep)
• AT+CWJAP: default <pmf> parameter is modified from 0 to 1 to improve Wi-Fi security as much as possible
• AT+RFPOWER: default BLE tx power parameters are modified from 0 to 2

Known Issue

• Sometimes a crash occurs before restarting when implementing AT+RST and AT+RESTORE command
• The power consumption in Deep-sleep mode is larger than the previous version in the default firmware. (You can revert it by disabling CONFIG_ESP32_RTC_CLK_SRC_EXT_CRYS, if you do not use BLE light sleep)

1. Feature

1.1 Wi-Fi

• Added AT+CWSTATE command to query Wi-Fi state
• AT+CWSTARTSMART: added support for ESP-Touch
• AT+CWLAP: added support for WAPI authmode
• Support multiple phy data (use different RF parameters according to the country code you set)

1.2 TCP/IP

• Enlarged send size of AT+CIPSEND command to 8 KiB
• Added AT+CIPSTATE command to query connection state
• Added AT+CIPSENDL and AT+CIPSENDLCFG commands to support long data send
• Support for passthrough mode when AT works as a server with only one connection
• Enabled Mbed TLS memory alloc from external RAM for ESP32-WROVER module
• AT+CIPTCPOPT: Added the <keep-alive> parameter
• AT+CIPSSLCCONF: Support more than 5 sets of ca certificates

1.3 Application Layer

• Added AT+MQTTALPN command to support MQTT ALPN
• Added AT+HTTPURLCFG command to configure long URL
• Added AT+HTTPCGET command to support HTTP GET request
• AT+HTTPCLIENT: <content-type> parameter can be omitted
• Added AT+CIPSNTPINTV command to configure SNTP sync interval
• Added AT+USEROTA command to support the upgrade of custom URL
• Added fallback DNS server. AT has two DNS servers ("208.67.222.222" and "8.8.8.8") by default.
• Added AT+USERDOCS command to query the ESP-AT user guide for the running firmware.

1.4 System

• Added AT+SLEEP query command
• Enabled external 32 kHz crystal to support BLE light sleep by default
• AT+RFPOWER: Wi-Fi tx power parameter can be omitted now
• Support ESP32 SDIO module

1.5 Bluetooth

• Support disabling BLE SPP auto-conn mode
• Support setting BLE HID name
• Support filtering scan result

1.6 Documentation

• Support choosing different docs depends on different targets
• Moved FAQ documents from ESP-FAQ to ESP-AT-FAQ
• Moved CSDN documentd about AT to ESP-AT
• Added more documents and improve document quality

2. Bugfix

2.1 Wi-Fi

• Fixed that AT+CWLAP returned ERROR sometimes.
• Fixed that AT+CWJAP returned wrong errno sometimes.
• Fixed an issue of auto connecting to WPA2 Enterprise AP. Users should always use AT+CWJEAP to connect to an WPA2 Enterprise AP.
• Fixed a potential crash when the length of SSID is 32 bytes or password is 64 bytes.

2.2 TCP/IP

• Fixed that AT+CIPSERVER=0,1 should only close clients connected to ESP TCP server.
• Fixed active write TCP data in passive mode.
• Fixed occasional crash in passthrough mode due to socket close.
• Fixed that OK and > responses were interrupted by other data.
• Fixed that AT+CIPSERVER=5 returned "Have 255 Connections".
• Fixed that AT+CIPTCPOPT send timeout parameter could not work sometimes.
• Fixed potential illegal assignment of AT+CIPTCPOPT command in multiple connection.
• AT+CIUPDATE: fixed the failure to do non-blocking OTA due to omitted parameters.
• Fixed that AT+CIPSTO did not reset the timer when data was sent
• Fixed that ssl connection was disconnected after receiving some data in passive read mode
• Fixed that AT+CIPSSLCPSK command could not work
• Fixed that AT+CIPSSLCCN and AT+CIPSSLCSNI maximum parameter length cannot be set to 64

2.3 Application Layer

• AT+HTTPCPOST: Fixed that the new content-type did not take effect becasue the default content-type was set incorrectly.
• Removed extra space in AT+HTTPCLIENT HEAD response.
• Fixed that AT+CIPDNS query command returned wrong config.
• Fixed the crash caused by setting wrong URLs in AT+HTTPCLIENT.

2.4 System

• Fixed a potential "busy p" issue.
• Fixed the issue of high power consumption after power on when set AT+CWMODE=0.
• Fixed the crash caused by setting the invalid GPIO wakeup config
• Fixed UART data blocks when the UART event notify is missing
• Fixed that socket interface of AT always returned busy p
• Fixed that UART1 printed extra chars during light sleep

2.5 Bluetooth

• Fixed BLE service discovery failure
• Fixed Classic Bluetooth build failure
• Fixed the failure to initiate BLE connection
• Fixed the format of response returned by AT+BLEENCDEV
• Fixed send indication failure
• Fixed the crash caused by BLE connection failure
• Fixed losing data over BLE SPP
• Fixed BT SPP memory leak

2.6 Tools

• Added utility tool at.py to modify the parameter configuration of factory firmware

3. Optimization

• Simplified esp-at build. Now, you can use ./build.py install to install all environments, and use ./build.py build to build the project.
• Added parameter check for AT+WPS command.
• Added parameter check for AT+CIPSERVER command.
• Added parameter check for AT+CIPTCPOPT command.
• Reduced potential NVS write at startup when NVS read the dirty data.

ESP32C3-AT

Documentation for Release v2.4.0.0 is available at https://docs.espressif.com/projects/esp-at/en/release-v2.4.0.0/esp32c3/index.html
ESP32C3-AT v2.4.0.0 is a major update for ESP32C3-AT v2.3.0.0.

This is the list of changes since release v2.3.0.0:

Breaking Changes

• esp-idf version updated to release v4.3 (588436db)
• AT+CWJAP: default <pmf> parameter is modified from 0 to 1 to improve Wi-Fi security as much as possible
• AT+RFPOWER: default BLE tx power parameters are modified from 0 to 2
• The AT+BLEADVPARAM command must be set before the AT+BLEADVDATA command (previous version does not have such a limit)

Known Issue

• The power consumption in Deep-sleep mode is larger than the previous version in the default firmware. (You can revert it by disabling CONFIG_ESP32_RTC_CLK_SRC_EXT_CRYS, if you do not use BLE light sleep.)

1. Feature

1.1 Wi-Fi

• Support multiple phy data (use different RF parameters according to the country code you set)

1.2 TCP/IP

• AT+CIPTCPOPT: Added the <keep-alive> parameter
• AT+CIPSSLCCONF: Support more than 5 sets of ca certificates

1.3 Application Layer

• Added AT+USERDOCS command to query the ESP-AT user guide for the running firmware.

1.4 System

• AT+RFPOWER: Wi-Fi tx power parameter can be omitted now
• Support ESP32-C3 SPI module

1.5 Bluetooth

• Support disabling BLE SPP auto-conn mode
• Support setting BLE HID name
• Support filtering scan result
• Support BLE 5.0 features

1.6 Documentation

• Support choosing different docs depends on different targets
• Moved the FAQ document from ESP-FAQ to ESP-AT-FAQ
• Moved CSDN documents about AT to ESP-AT
• Added more documents and improve document quality

2. Bugfix

2.1 Wi-Fi

• No bugfix

2.2 TCP/IP

• Fixed that AT+CIPSTO did not reset the timer when data was sent
• Fixed occasional failure when AT+CIPSERVERMAXCONN=5 was set
• Fixed that ssl connection was disconnected after receiving some data in passive read mode
• Fixed that AT+CIPSSLCPSK command could not work
• Fixed occasional print of 0,CONNECT in passthrough mode
• Fixed potential illegal assignment of AT+CIPTCPOPT command in multiple connection
• Fixed that extra data output if tcp client reconnected when esp-at works as a tcp server in passthrough mode
• Fixed that AT+CIPSSLCCN and AT+CIPSSLCSNI maximum parameter length cannot be set to 64

2.3 Application Layer

• No bugfix

2.4 System

• Fixed the crash caused by setting the invalid GPIO wakeup config
• Fixed that socket interface of AT always returned busy p
• Fixed the crash when an invalid parameter was set for AT+DRVADV command
• Fixed that UART1 printed extra chars during light sleep

2.5 Bluetooth

• Fixed BLE service discovery failure
• Fixed the failure to initiate BLE connection
• Fixed the format of response returned by AT+BLEENCDEV command
• Fixed send indication failure
• Fixed the crash caused by BLE connection failure
• Fixed losing data over BLE SPP

2.6 Tools

• Added utility tool at.py to modify the parameter configuration of factory firmware

3. Optimization

• Simplified esp-at build. Now, you can use ./build.py install to install all environments and use ./build.py build to build the project.
• Added the coexistence check for AT+CIPMODE, AT+CIPSTART, and AT+CIPSERVER command.