AT+USERRAM : Operate user’s free RAM.
AT+USEROTA : Upgrade the firmware according to the specified URL.
AT+USERWKMCUCFG : Configure how AT wakes up MCU.
AT+USERMCUSLEEP : MCU indicates its sleep state.
AT+USERDOCS : Query the ESP-AT user guide for current firmware.
| Variant | Command | Response | Function |
|---|---|---|---|
| Query Command | Function: | Query current available user’s RAM size. | Command: |
| AT+USERRAM? | Response: | +USERRAM:<size> | OK |
Response:
+USERRAM:< size> OK
Function:
Operate user’s free RAM
Command:
AT+ USERRAM=<operation>,<size>[,<offset>]
Response:
+USERRAM:<length>,<data> // esp-at returns this response only when the operator is ``read`` OK
<operation> :
0: release user’s RAM
1: malloc user’s RAM
2: write user’s RAM
3: read user’s RAM
4: clear user’s RAM
<size> : the size to malloc/read/write
<offset> : the offset to read/write. Default: 0
Please malloc the RAM size before you perform any other operations.
If the operator is
write
, wrap return
>
after the write command, then you can send the data that you want to write. The length should be parameter
<length>
.
If the operator is
read
and the length is bigger than 1024, ESP-AT will reply multiple times in
the same format, each reply can carry up to 1024 bytes of data, and
eventually end up with
\r\nOK\r\n
.
//
malloc
1
KB
user
's RAM
AT+
USERRAM=
1,
1024//
write
500
bytes
to
RAM (
offset:
0)
AT+
USERRAM=
2,
500//
read
64
bytes
from
RAM
offset
100
AT+
USERRAM=
3,
64,
100//
free
the
user
's RAM
AT+
USERRAM=
0
ESP-AT upgrades firmware at runtime by downloading the new firmware from a specific URL.
Function:
Upgrade to the firmware version specified by the URL.
Command:
AT+
USEROTA=<
url
len>
Response:
OK>
This response indicates that AT is ready for receiving URL. You should enter the URL, and when the URL length reaches the
<url
len>
value, the system returns:
Recv <
url
len>
bytes
After AT outputs the above information, the upgrade process starts. If the upgrade process is complete, the system return:
OK
If the parameter is wrong or firmware upgrades fails, the system returns:
ERROR
<url len> : URL length. Maximum: 8192 bytes.
The speed of the upgrade depends on the network status.
If the upgrade fails due to unfavorable network conditions, AT will return
ERROR
. Please wait for some time before retrying.
After you upgrade the AT firmware, you are suggested to call the command AT+RESTORE to restore the factory default settings.
AT+USEROTA
supports
HTTP
and
HTTPS
.
After AT outputs the
>
character, the special characters in the URL does not need to be
escaped through the escape character, and it does not need to end with a
new line(CR-LF).
When the URL is
HTTPS
,
SSL verification is not recommended. If SSL verification is required,
you need to generate your own PKI files and download them into the
corresponding partition, and then load the certificates in the code
implemented by the
AT+USEROTA
command. Please refer to
How to Generate PKI Files
for PKI files. For
AT+USEROTA
command, ESP-AT project provides an example of
USEROTA .
Please refer to How to Implement OTA Upgrade for more OTA commands.
AT+
USEROTA=
36
OK>
Recv
36
bytes
OK
Function:
This command configures how AT checks whether MCU is in awake state and how to wake it up.
If MCU is in awake state, AT will directly send the data to it without waking it up.
If MCU is in sleep state and AT is ready to actively send the data to MCU (the data sent actively is same to ESP-AT Message Reports ), AT will send wake signals to wake it up first and then send the data to it. Wake signals will be cleared after MCU is waked up or timeout.
Command:
AT+ USERWKMCUCFG=< enable>,< wake mode>,< wake number>,< wake signal>,< delay time>[,< check mcu awake method>]