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: