Command Reference

Index

1. About
2. Core AT Commands
3. AT& extended commands
4. AT+ commands
5. AT$ configuration variables
6. ATS registers
7. Espressif AT commands

About

This contains a full list of Hayes-style AT commands compatible with the PerryZi firmware. Note that, for the majority of commands that use quotes, those quotes are optional unless the parameter contains one or more spaces. This is not true, however, for Espressif commands, and quotes should always be used if expected by the command.

Core AT commands

Command	Description
AT	Attention prefix. On its own, returns OK. Prefixes all commands below.
ATA	Answer / accept a waiting incoming connection.
ATB<n>	Set the serial baud rate. A comma-separated suffix may set the line format (data/parity/stop).
ATC	Connect: bring up wifi (and/or open the pending connection).
ATD"host:port" ATDT"host:port"	Dial a remote host and enter online (stream) mode. The T in ATDT is optional.
ATE<n>	Echo: 0 - off 1 - on
ATF<n>	Serial flow-control type: 0 - RTS/CTS 1 - XON/XOFF, 2 - XON/XOFF auto-off 3 - manual 4 - disabled
ATH	Hang up: close all open connections.
ATI<n>	Information: 0 / 1 / 5 - settings strings 2 - IP 3 - SSID 4 - firmware version 6 - MAC 7 - date/time 8 - build date 9 - network details 10 - last printer spec 11 - free heap
ATL	Re-send the last packet on a connection.
ATM	Hayes compatibility (speaker control); no operation.
ATN<n>	Create or remove a TCP listener (server) port.
ATO	Return to online (stream) mode with the current connection, or dial a phonebook entry by number.
ATP	Phonebook: list, add or remove stored dialling entries.
ATQ<n>	Quiet mode: 0 - enable result codes 1 - suppress result codes
ATR<n>	Line-ending mode: 0 - CR 1 - CRLF 2 - LFCR 3 - LF
ATRD / ATRT	Display the current UTC date/time obtained via NTP from uk.pool.ntp.org in NIST time format: YY-MM-DD HH:MM:SS Implemented to maintain compatibility with ST.COM
ATS<n>? / ATS<n>=<v>	Read or write an S-register. See the ATS registers table below.
ATT	Transmit a data packet to the current connection (optional CRC).
ATV<n>	Result-code style: 0 - numeric 1 - verbose
ATW	WiFi: scan/list access points, or connect with: ATW"SSID,PASSWORD"
ATX<n>	Result-code set: 0 - short 1 - long/extended
ATY	Hayes compatibility; no operation.
ATZ	Reset the modem and reload the last saved configuration.

AT& extended commands

Command	Description
AT&D<c>	Append a character to the delimiter set.
AT&F	Factory reset.
AT&F86	Factory reset, and reformat the SPIFFS filesystem.
AT&G	Fetch/stream a web URL to the terminal.
AT&K<n>	Flow-control shortcut: 0 / 1 / 2 - off 3 / 6 - RTS/CTS 4 / 5 - XON/XOFF.
AT&L	Reload configuration from flash.
AT&M<c>	Append a character to the "mask-out" set (bytes stripped from the stream).
AT&N<n> / AT&N<n>=<v>	Read or force a GPIO pin.
AT&O<n>	Start logging if no argument is provided. Debug log control: 0 - dump log 86 / 87 - delete log 88 - log and echo to UART
AT&S<n>=<value>	Set a string setting: 40 - mDNS hostname 41 - terminal type 42 - busy message
AT&T	Show the current time. Configure the timezone: AT&T<args>
AT&W	Save the current configuration to flash.
AT&Y...	Define the escape/state-machine sequence.

AT+ commands

Command	Description
AT+CONFIG	Enter the interactive configuration menu.
AT+IRC	Enter IRC chat mode.
AT+PING"host"	Ping a host to test connectivity/DNS.
AT+PPP	Enter PPP networking mode.
AT+PRINT<mode>:<host>:<port>/<path>	Print to a CUPS/IPP printer. Mode is Ascii, or Raw.
AT+SLIP	Enter SLIP networking mode.

AT$ configuration variables

Command	Description
AT$MDNS=<value>	Set the mDNS hostname.
AT$PASS=<value>	Set the wifi password.
AT$SB=<value>	Set the serial baud rate.
AT$SSID=<value>	Set the wifi SSID.

ATS registers

Read a register with ATS<n>? and set one with ATS<n>=<v>.

Register	Meaning	Values
0	Auto-answer: number of rings before answering an incoming connection (0 disables auto-answer).	0 to 255
2	Escape character used in the +++ escape sequence.	0 to 255
3	Carriage-return character code.	0 to 127
4	Line-feed character code.	0 to 127
5	Backspace character code.	0 to 32
40	Streaming packet size, in bytes.	≥ 1
41	Auto-stream mode; enter stream mode automatically on answer/connect:	0 - off >0 - on
42	CRC-8 value used by the transmit command (ATT).	0 to 255
43	Temporary baud rate applied to the next dialled connection.	baud rate ≤0 - clear
44	Inter-character serial output delay, in milliseconds.	≥ 0
45	Binary translation type for streaming.	0 to (BTYPE_INVALID−1)
46	DCD line polarity mode.	0 - normal 1 - inverted 2 - always active 3 - always inactive
47	GPIO pin assigned to DCD (output).	supported pin 0 to MAX_PIN_NO
48	CTS line polarity mode.	0 - normal 1 - inverted 2 - always active 3 always inactive
49	GPIO pin assigned to CTS (input).	supported pin 0 to MAX_PIN_NO
50	RTS line polarity mode.	0 - normal 1 - inverted 2 - always active 3 - always inactive
51	GPIO pin assigned to RTS (output).	supported pin 0 to MAX_PIN_NO
52	RI (ring indicator) line polarity mode.	0 - normal 1 - inverted 2 - always active 3 - always inactive
53	GPIO pin assigned to RI (output).	supported pin 0 to MAX_PIN_NO
54	DTR line polarity mode.	0 - normal 1 - inverted 2 - always active 3 - always inactive
55	GPIO pin assigned to DTR (input).	supported pin 0 to MAX_PIN_NO
56	DSR line polarity mode.	0 - normal 1 - inverted 2 - always active 3 - always inactive
57	GPIO pin assigned to DSR (output).	supported pin 0 to MAX_PIN_NO
60	Preserve TCP listeners across resets (persisted to flash).	0 - off non-0 - on
61	Printer job completion timeout, in seconds.	> 0
62	Telnet protocol handling on connections.	0 - off >0 - on
63	Hang-up trigger type.	0 - none 1- PPP-hard 2 - DTR 3 - PDP
64	Discard incoming NUL bytes.	0 - off >0 - on

Espressif AT commands

These commands provide compatibility with software written for the stock Espressif ESP-AT firmware, so that utilities expecting this command set will continue to work. They are available from PerryZi 1.2.4.

The MOD-WIFI-ESP8266 build for the Agon Light / Neo6502 uses the Espressif v1.7.6.0 (NonOS) command set, whereas all other builds use the v2.3.0.0 (ESP-AT) command set. This is due to existing Agon Light and Neo6502 software being written for the older Espressif firmware.

Differences between command sets

	v1.7.6.0	v2.3.0.0
AT+CIPRECVDATA reply	,<len>:<data>	:<len>,<data>
_CUR / _DEF suffixes	accepted	not accepted
AT+CIPDOMAIN reply	:<ip>	:"<ip>"
Failed AT+CWJAP returns	FAIL	ERROR

Compatibility Scope

A single connection only, so AT+CIPMUX accepts 0 alone. Plain TCP and UDP only: there is no TLS in PerryZi, so the SSL transmission type and the AT+CIPSSLC* family are unsupported. IPv6 is unavailable because the ESP8266 Arduino core is built with LWIP_IPV6=0, so the v6 transmission types are rejected.

AT and ATE<n> are used by this command set too, and behave as described in Core AT commands above.

Basic and system

Command	Description
AT+RST	Reset the AT layer: closes any open connection and returns AT+CIPRECVMODE, AT+CIPDINFO and AT+CIPMODE to their defaults. Replies OK followed by ready. Note this does not reboot the module, which would drop the host's serial settings.
AT+RESTORE	Behaves as AT+RST above. Unlike stock firmware it does not erase the saved configuration; use AT&F for that.
AT+GMR	Version information, as four lines: AT version: SDK version: compile time: Bin version:
AT+CMD?	List the Espressif commands this firmware supports, as +CMD: lines.
AT+SYSRAM?	Free heap, in bytes: +SYSRAM:<free>
AT+SYSSTORE=<n> / AT+SYSSTORE?	Accept or report the persist-settings flag: +SYSSTORE:<n> PerryZi writes configuration to flash with AT&W, so this flag is recorded but does not itself save anything.
AT+GSLP=<ms>	Enter deep sleep for the given number of milliseconds.

Wifi

Command	Description
AT+CWMODE=1 / AT+CWMODE?	Station mode. Values other than 1 return ERROR; SoftAP is not supported. +CWMODE:1
AT+CWJAP="SSID","PASSWORD"	Join an access point. On success replies WIFI CONNECTED and WIFI GOT IP, then OK; on failure +CWJAP:4 then FAIL. As with ATW, this updates the live settings only - use AT&W to persist them.
AT+CWJAP?	Report the current access point: +CWJAP:"<ssid>","<bssid>",<channel>,<rssi> or No AP when not connected.
AT+CWQAP	Disconnect from the current access point.
AT+CWLAP	Scan for access points, one line each: +CWLAP:(<ecn>,"<ssid>",<rssi>,"<mac>",<channel>)
AT+CWAUTOCONN=<n>	Automatic reconnection: 0 - off 1 - on
AT+CWSTATE?	Connection state: +CWSTATE:<state>,"<ssid>"
AT+CWHOSTNAME=<name> / AT+CWHOSTNAME?	Read or set the mDNS hostname: +CWHOSTNAME:<name>
AT+CWRECONNCFG=<interval>[,<repeat>] / AT+CWRECONNCFG?	Reconnection interval, in seconds: +CWRECONNCFG:<interval>,0
AT+CWCOUNTRY?	Report the WiFi country settings: +CWCOUNTRY:<policy>,"<country code>",<start channel>,<channel count>
AT+CWCOUNTRY=<policy>,"<cc>",<start>,<count>	Set the WiFi country settings. <policy>: 0 - auto 1 - manual
AT+RFPOWER=<n> / AT+RFPOWER?	Transmit power, in units of 0.25 dBm: +RFPOWER:<n>
AT+SLEEP=<n> / AT+SLEEP?	WiFi sleep mode: 0 - none 1 - light 2 - modem

Addressing

Command	Description
AT+CIFSR	Station address, as two lines: +CIFSR:STAIP,"<ip>" +CIFSR:STAMAC,"<mac>"
AT+CIPSTA?	IPv4 configuration, as three lines: +CIPSTA:ip:"<ip>" +CIPSTA:gateway:"<gateway>" +CIPSTA:netmask:"<netmask>"
AT+CIPSTA="<ip>"[,"<gateway>"[,"<netmask>"]]	Set a static address for this session.
AT+CIPSTAMAC?	Station MAC address: +CIPSTAMAC:"<mac>"
AT+CIPDNS?	Report the DNS servers in use: +CIPDNS:<manual>,"<dns1>"[,"<dns2>"]
AT+CIPDNS=1,"<dns1>"[,"<dns2>"]	Set the DNS server(s) manually. AT+CIPDNS=0, which returns DNS to DHCP control, returns ERROR: lwIP will only do that on a fresh lease.
AT+CIPDOMAIN="<host>"	Resolve a hostname: +CIPDOMAIN:"<ip>"

Connections

Command	Description
AT+CIPMUX=0 / AT+CIPMUX?	Single-connection mode. 1 returns ERROR. +CIPMUX:0
AT+CIPMODE=0 / AT+CIPMODE?	Normal transmission mode. 1 (passthrough) returns ERROR. +CIPMODE:0
AT+CIPDINFO=<n>	Include the remote address and port in +IPD and +CIPRECVDATA replies: 0 - off 1 - on
AT+CIPSTART="TCP","<host>",<port>[,<keepalive>] AT+CIPSTART="UDP","<host>",<remote port>[,<local port>] AT+CIPSTARTEX=...	Open a connection. Replies CONNECT then OK. Returns ERROR if a connection is already open (preceded by ALREADY CONNECTED), or if the SSL or v6 transmission types are requested.
AT+CIPSEND=<length>	Send data. Replies OK then the > prompt, after which exactly <length> raw bytes are read from the serial port. These bytes are taken verbatim: NUL, CR and LF are all passed through unaltered. On completion replies Recv <n> bytes then SEND OK, or SEND FAIL. Maximum 2048 bytes.
AT+CIPCLOSE	Close the connection. Replies CLOSED then OK.
AT+CIPSTATUS	Connection status: STATUS:<state> +CIPSTATUS:0,"<type>","<remote ip>",<remote port>,<local port>,0
AT+CIPSTATE?	As AT+CIPSTATUS but without the STATUS: line.
AT+CIPSTO=<seconds> / AT+CIPSTO?	Server timeout: +CIPSTO:<seconds>
AT+CIPSERVERMAXCONN=<n> / AT+CIPSERVERMAXCONN?	Maximum server connections: +CIPSERVERMAXCONN:<n>
AT+CIPSERVER	Always returns ERROR: a server requires AT+CIPMUX=1, which is not supported. Use ATN<n> instead.
AT+CIPTCPOPT?	Report TCP socket options.

Receiving data

Two receive models are supported, selected with AT+CIPRECVMODE.

In active mode (the default, AT+CIPRECVMODE=0) incoming data is pushed to the serial port as it arrives, prefixed with +IPD,<length>: and followed by the data itself. With AT+CIPDINFO=1 the prefix becomes +IPD,<length>,"<remote ip>",<remote port>:.

In passive mode (AT+CIPRECVMODE=1) the arrival of data is announced once with +IPD,<length> and no data follows. The data is then read explicitly with AT+CIPRECVDATA. A further announcement is not made until the buffer has been drained.

Command	Description
AT+CIPRECVMODE=<n> / AT+CIPRECVMODE?	Receive model: 0 - active 1 - passive +CIPRECVMODE:<n>
AT+CIPRECVDATA=<length>	Read up to <length> buffered bytes: +CIPRECVDATA:<actual length>,<data> Buffered data stays readable after the remote end disconnects. Once the buffer is empty and the connection has gone, ERROR is returned.
AT+CIPRECVLEN?	Bytes currently buffered: +CIPRECVLEN:<length>,0,0,0,0

Time

Command	Description
AT+CIPSNTPCFG=<enable>,<timezone>[,"<server>"] / AT+CIPSNTPCFG?	Read or set the SNTP configuration. <enable> 0 disables time updates, 1 enables them and forces an immediate update. The server defaults to uk.pool.ntp.org. +CIPSNTPCFG:<enable>,<timezone>,"<server>"
AT+CIPSNTPTIME?	Current time in asctime format: +CIPSNTPTIME:<Day> <Mon> <date> <hh:mm:ss> <year> Returns ERROR if the time has not yet been set.
AT+SYSTIMESTAMP?	Current time as a Unix epoch value: +SYSTIMESTAMP:<epoch> Returns ERROR if the time has not yet been set.

Diagnostics

Command	Description
AT+PING="<host>"	Ping a host: +PING:<milliseconds> or +PING:TIMEOUT followed by ERROR. PerryZi's own AT+PING"<host>" form, described in AT+ commands above, is unaffected and continues to work: the two are told apart by the =.