ESP8266 - AT Command Reference
ESP8266, in it’s default configuration, boots up into the serial modem mode. In this mode you
can communicate with it using a set of AT commands. I will present to you a reference
of all known AT commands that ESP8266 supports, explain what they do and how to use them.
Historically AT commands are based on the Hayes Command Set and these are no different.
AT Commands
Index of all known AT commands
Line termination
ESP8266 expects <CR><LF> or CarriageReturn and LineFeed at the end of each command,
but just<CR> seems to work too.
Command variants
Each command can have up to 4 variants changing the function of it. You can
chose between them by appending one of four possible values to the end of the
root command itself. These four appendices can have the following values
"",=<parameter|[parameters]>,"?",=?
| Type |
Example |
Description |
| Test |
AT+CIPSTART=? |
Query the range of values (So far only AT+CWMODE=? uses it) |
| Query |
AT+CMD? |
Returns the current value of the parameter. |
| Set |
AT+CMD=Parameter |
Set the value of user-defined parameters in commands and run. |
| Execute |
AT+CMD |
Runs commands with no user-defined parameters. |
Note:
- Not all AT commands support all 4 variants.
- [] = default value, not required or may not appear.
- String values require double quotation marks, for example:
AT+CWSAP="ESP756190","21030826",1,4.
- Baud rate = 115200
- AT instruction ends with “\r\n”
Commands
| Variant |
Command |
Response |
Function |
| Execute |
AT |
OK |
Test if AT system works correctly |
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| Variant |
Command |
Response |
Function |
| Execute |
AT+RST |
OK |
Reset the module |
ESP-01 Output after reset:
ets Jan 8 2013,rst cause:4, boot mode:(3,7)
wdt reset
load 0x40100000, len 24444, room 16
tail 12
chksum 0xe0
ho 0 tail 12 room 4
load 0x3ffe8000, len 3168, room 12
tail 4
chksum 0x93
load 0x3ffe8c60, len 4956, room 4
tail 8
chksum 0xbd
csum 0xbd
ready
ESP-12 Output after reset:
\0x04B1\0x85 \0xff\0x13:'\0xe0;\0xcc;!G\0xfa\0x11\0xa9R\0xc6\0x83\0x01\0xd9\0x81
[Vendor:www.ai-thinker.com Version:0.9.2.4]
ready
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| Variant |
Command |
Response |
Function |
| Execute |
AT+GMR |
version, OK |
Print firmware version |
Parameters:
version: firmware version number
ESP-01 output:
ESP-12 output:
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| Variant |
Command |
Response |
Function |
| set |
AT+GSLP=time |
time OK |
Enter deep sleep mode for time milliseconds |
parameters:
time: Time to sleep in milliseconds
Example：
AT+GSLP=1500
Note:
Hardware has to support deep-sleep wake up (Reset pin has to be High).
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| Variant |
Command |
Response |
Function |
| Execute |
ATE0 |
OK |
Disable echo (Doesn’t send back received command) |
| Execute |
ATE1 |
OK |
Enable echo (Sends back received command before response) |
Note:
I haven’t had any luck with this command yet. Both ATE0 and ATE1 return no this fun.
ATE returns OK
This changed with ESP-12 where the command functions exactly as expected!
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| Variant |
Command |
Response |
Function |
| Test |
AT+CWMODE=? |
+CWMODE:(1-3) OK |
List valid modes |
| Query |
AT+CWMODE? |
+CWMODE:mode OK |
Query AP’s info which is connect by ESP8266. |
| Execute |
AT+CWMODE=mode |
OK |
Set AP’s info which will be connect by ESP8266. |
Parameters:
mode： An integer designating the mode of operation either 1, 2, or 3.
1 = Station mode (client)
2 = AP mode (host)
3 = AP + Station mode (Yes, ESP8266 has a dual mode!)
Notes:
ESP-12 came configured as host with ssid set to ESP_A0A3F2, no password, channel 1
You can use AT+CWSAP? to find the current settings.
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| Variant |
Command |
Response |
Function |
| Query |
AT+CWJAP? |
+ CWJAP:ssid OK |
Prints the SSID of Access Point ESP8266 is connected to. |
| Execute |
AT+CWJAP=ssid,pwd |
OK |
Commands ESP8266 to connect a SSID with supplied password. |
Parameters:
ssid：String, AP’s SSIDpwd：String, not longer than 64 characters
Example：
AT+CWJAP="my-test-wifi","1234test"
Example AT+CWJAP?：
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| Variant |
Command |
Response |
Function |
| Set |
AT+CWLAP=ssid,mac,ch |
+CWLAP:ecn,ssid,rssi,mac OK |
Search available APs with specific conditions. |
| Execute |
AT+CWLAP |
AT+CWLAP:ecn,ssid,rssi,mac OK |
Lists available Access Points. |
Parameters:
ecn:
- 0 = OPEN
- 1 = WEP
- 2 = WPA_PSK
- 3 = WPA2_PSK
- 4 = WPA_WPA2_PSK
ssid: String, SSID of APrssi: signal strengthmac: String, MAC address
Note:
On ESP-01 I have had no luck with the set version of this command (AT+CWLAP=...). If you know what it does
please let me know.
On ESP-12, the Set version of the command allows to see if a certain SSID, with certain MAC on
certain channel exists. If it doesit is returned as one line of the Execute version of this command.
Example AT+CWLAP:
+CWLAP:(3,"CVBJB",-71,"f8:e4:fb:5b:a9:5a",1)
+CWLAP:(3,"HT_00d02d638ac3",-90,"04:f0:21:0f:1f:61",1)
+CWLAP:(3,"CLDRM",-69,"22:c9:d0:1a:f6:54",1)
+CWLAP:(2,"AllSaints",-88,"c4:01:7c:3b:08:48",1)
+CWLAP:(0,"AllSaints-Guest",-83,"c4:01:7c:7b:08:48",1)
+CWLAP:(0,"AllSaints-Guest",-83,"c4:01:7c:7b:05:08",6)
+CWLAP:(4,"C7FU24",-27,"e8:94:f6:90:f9:d7",6)
+CWLAP:(2,"AllSaints",-82,"c4:01:7c:3b:05:08",6)
+CWLAP:(3,"QGJTL",-87,"f8:e4:fb:b5:6b:b4",6)
+CWLAP:(4,"50EFA8",-78,"74:44:01:50:ef:a7",6)
+CWLAP:(0,"optimumwifi",-78,"76:44:01:50:ef:a8",6)
+CWLAP:(3,"BHQH4",-95,"18:1b:eb:1a:af:5b",6)
+CWLAP:(3,"NETGEAR49",-86,"84:1b:5e:e0:28:03",7)
+CWLAP:(3,"ngHub_319332NW00047",-56,"20:e5:2a:79:b1:2f",11)
+CWLAP:(3,"BFZR4",-73,"18:1b:eb:1d:c3:91",11)
+CWLAP:(1,"5FFVL",-82,"00:26:b8:b5:c0:f2",11)
+CWLAP:(3,"59G6D",-77,"00:7f:28:6d:91:7b",11)
+CWLAP:(3,"N16FU",-53,"20:cf:30:ce:60:fe",11)
+CWLAP:(3,"ITS",-82,"90:72:40:21:5f:76",11)
+CWLAP:(3,"ITS",-79,"24:a2:e1:f0:04:e4",11)
Example AT+CWLAP="N16FU","20:cf:30:ce:60:fe",11:
+CWLAP:(3,"N16FU",-53,"20:cf:30:ce:60:fe",11)
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| Variant |
Command |
Response |
Function |
| Execute |
AT+CWQAP |
OK |
Disconnect ESP8266 from the AP is currently connected to. |
Note:
After running this command, if you run AT+CWJAP? it still shows the AP you were connected to before.
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| Variant |
Command |
Response |
Function |
| Query |
AT+CWSAP? |
+CWSAP:ssid,pwd,ch,ecn OK |
Query configuration of ESP8266 softAP mode. |
| Set |
AT+CWSAP=ssid,pwd,ch,ecn |
OK |
Set configuration of softAP mode. |
Parameters:
ssid: String, ESP8266’s softAP SSIDpwd: String, Password, no longer than 64 charactersch: channel idecn:
- 0 = OPEN
- 2 = WPA_PSK
- 3 = WPA2_PSK
- 4 = WPA_WPA2_PSK
Example
AT+CWSAP="esp_123","1234test",5,3
AT+CWSAP? => +CWSAP:"esp_123","1234test",5,3
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| Variant |
Command |
Response |
Function |
| Execute |
AT+CWLIF |
[ip,other] OK |
List information on of connected clients. |
Parameters:
ip: IP address of a client connected to the ESP8266 softAP
other: Other info, look at example. I don’t know what it means yet.
Example (ESP-01):
AT+CWLIF
192.168.4.100,3fff50b4:3fff50ba:3fff50c0:3fff50c6:3fff50cc:3fff50d2
OK
Example (ESP-12):
AT+CWLIF
192.168.4.100,c0:ee:fb:25:33:ec
OK
I ran the command after connecting to the ESP8266 with my cellphone.
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| Variant |
Command |
Response |
Function |
| Set |
AT+CWDHCP=mode,en |
OK |
Enable or disable DHCP for selected mode |
Parameters:
mode:
- 0 : set ESP8266 as a softAP
- 1 : set ESP8266 as a station
- 2 : set both ESP8266 to both softAP and a station
en:
- 0 : Enable DHCP
- 1 : Disable DHCP
Note:
This command doesn’t seem to work on firmware 00160901 (ESP-01) nor
0018000902-AI03 (ESP-12).
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| Variant |
Command |
Response |
Function |
| Query |
AT+CIPSTAMAC? |
+CIPSTAMAC:mac OK |
Print current MAC ESP8266’s address. |
| Execute |
AT+CIPSTAMAC=mac |
OK |
Set ESP8266’s MAC address. |
Parameters:
mac： String, MAC address of the ESP8266 station.
Example:
AT+CIPSTAMAC="18:aa:35:97:d4:7b"
Note:
This command doesn’t seem to work on firmware 00160901
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| Variant |
Command |
Response |
Function |
| Query |
AT+CIPAPMAC? |
+CIPAPMAC:mac OK |
Get MAC address of ESP8266 softAP. |
| Execute |
AT+CIPAPMAC=mac |
OK |
Set mac of ESP8266 softAP. |
Parameters:
mac： String, MAC address of the ESP8266 softAP.
Example:
AT+CIPAPMAC=”2c:aa:35:97:d4:7b”
Note:
This command doesn’t seem to work on firmware 00160901
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| Variant |
Command |
Response |
Function |
| Query |
AT+CIPSTA? |
+CIPSTA:ip OK |
Get IP address of ESP8266 station. |
| Execute |
AT+CIPSTA=ip |
OK |
Set ip addr of ESP8266 station. |
Parameters:
ip： String, ip address of the ESP8266 station.
Example:
AT+CIPSTA=”192.168.101.108”
Note:
This command doesn’t seem to work on firmware 00160901
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| Variant |
Command |
Response |
Function |
| Query |
AT+CIPAP? |
+CIPAP:ip OK |
Get ip address of ESP8266 softAP. |
| Execute |
AT+CIPAP=ip |
OK |
Set ip addr of ESP8266 softAP. |
Parameters:
ip： String, ip address of ESP8266 softAP.
Example:
Note:
This command doesn’t seem to work on firmware 00160901
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| Variant |
Command |
Response |
Function |
| Test |
AT+CIPSTATUS=? |
OK |
|
| Execute |
AT+CIPSTATUS |
STATUS:status +CIPSTATUS:id,type,addr,port,tetype OK |
Get information about connection. |
Parameters:
status：
- 2: Got IP
- 3: Connected
- 4: Disconnected
id： id of the connection (0~4), for multi-connecttype： String, “TCP” or “UDP”addr： String, IP address.port： port numbertetype：
- 0 = ESP8266 runs as a client
- 1 = ESP8266 runs as a server
Note:
On ESP-01 this command returns STATUS:1 instead (no extra info, but status changes)
On 0018000902-AI03 this command returns STATUS:2 instead (no extra info, but status changes)
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| Variant |
Command |
Response |
Function |
| Set |
AT+CIPSTART=type,addr,port |
OK |
Start a connection as client. (Single connection mode) |
| Set |
AT+CIPSTART=id,type,addr,port |
OK |
Start a connection as client. (Multiple connection mode) |
| Test |
AT+CIPSTART=? |
[+CIPSTART:(id)(“type”),(“ip address”),(port)] OK |
List possible command variations) |
Parameters:
id: 0-4, id of connectiontype: String, “TCP” or “UDP”addr: String, remote IPport: String, remote port
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| Variant |
Command |
Response |
Function |
| Test |
AT+CIPSEND=? |
OK |
|
| Set |
AT+CIPSEND=length |
SEND OK |
Set length of the data that will be sent. For normal send (single connection). |
| Set |
AT+CIPSEND=id,length |
SEND OK |
Set length of the data that will be sent. For normal send (multiple connection). |
| Execute |
AT+CIPSEND |
|
Send data. For unvarnished transmission mode. |
Normal Mode
Parameters:
id: ID no. of transmit connectionlength: data length, MAX 2048 bytes
Unvarnished Transmission Mode
Wrap return “>” after execute command. Enters unvarnished transmission, 20ms interval between
each packet, maximum 2048 bytes per packet. When single packet containing “+++” is received, it
returns to command mode.
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| Variant |
Command |
Response |
Function |
| Test |
AT+CIPCLOSE=? |
OK |
|
| Set |
AT+CIPCLOSE=id |
OK |
Close TCP or UDP connection.For multiply connection mode |
| Execute |
AT+CIPCLOSE |
OK |
Close TCP or UDP connection.For single connection mode |
Parameters:
id： ID no. of connection to close, when id=5, all connections will be closed.
Note:
In server mode, id = 5 has no effect!
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| Variant |
Command |
Response |
Function |
| Test |
AT+CIFSR=? |
OK |
|
| Execute |
AT+CIFSR |
+CIFSR:ip OK |
Get local IP address. |
Parameters:
ip: IP address of the ESP8266 as an client.
Example AT+CIFSR:
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| Variant |
Command |
Response |
Function |
| Set |
AT+CIPMUX=mode |
OK |
Enable / disable multiplex mode (up to 4 conenctions) |
| Query |
AT+CIPMUX? |
+CIPMUX:mode OK |
Print current multiplex mode. |
Parameters:
mode:
- 0: Single connection
- 1: Multiple connections (MAX 4)
NOTE:
This mode can only be changed after all connections are disconnected. If server is started, reboot is required.
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| Variant |
Command |
Response |
Function |
| Set |
AT+CIPSERVER=mode[,port] |
OK |
Configure ESP8266 as server |
Parameters:
mode:- 0: Delete server (need to follow by restart)
- 1: Create server
port: port number, default is 333
NOTE:
- Server can only be created when AT+CIPMUX=1
- Server monitor will automatically be created when Server is created.
- When a client is connected to the server, it will take up one connection，be gave an id.
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| Variant |
Command |
Response |
Function |
| Query |
AT+CIPMODE? |
+CIPMODE:mode OK |
Set transfer mode,normal or transparent transmission. |
| Set |
AT+CIPMODE=mode |
OK |
Set transfer mode,normal or transparent transmission. |
Parameters:
mode:- 0: normal mode
- 1: unvarnished transmission mode
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| Variant |
Command |
Response |
Function |
| Query |
AT+CIPSTO? |
+CIPSTO:time |
Query server timeout. |
| Set |
AT+CIPSTO=time |
OK |
Set server timeout. |
Parameters:
time: server timeout, range 0~7200 seconds
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!!! Don’t run this unless you know what you’re doing !!!
### !!! It will likely brick your device !!!
Attempts to self-update from the internet.
| Variant |
Command |
Response |
Function |
| Execute |
AT+CIUPDATE |
+CIPUPDATE:n OK |
Start update through network |
Parameters:
-n:
- 1: found server
- 2: connect server
- 3: got edition
- 4: start update
Example:
AT+CIUPDATE
+CIUPDATE: 1
+CIUPDATE: 2
+CIUPDATE: 3
+CIUPDATE: 4
\0x02\0x8cl\0x8el\0x8e\0x1cp\0x0c\0x8c\0xf2nn\0xee\0x00l\0x8c\0x8el`
\0x02\0x90\0x12\0x12nnl\0x8cl`\0x02\0x0e\0x02nr\0x8e\0x92\0x92n\0x0c\0x0c
\0x02\0x8c\0x92`\0x02`
\0xf2n\0x0c\0x0c\0x0c\0x9e\0xe0b\0x82nl\0x8c\0x0c\0x8c
\0xf2nn\0xee\0x00\0x0c\0x8e\0x0elp\0xf2n\0xe0\0x10\0x02\0x0c
\0x0cr\0x8c\0x9c\0x9c\0xe2\0xe0\0x0c\0x0c\0x0c
\0x0cb\0x0cn\0xe2|\0x02\0xec\0xecl\0x8c\0x0cb\0x8c\0xf2nn
...forever
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| Variant |
Command |
Response |
Function |
| Execute |
|
+IPD,len:data |
Receive network data from single connection. |
| Execute |
|
+IPD,id,len:data |
Receive network data from multiple connection. |
Parameters:
id: id no. of connectionlen: data lengthdata: data received
Note:
I have had no luck with this command so far.
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Sources
esp8266 GitHub Wiki