ESP8266 Serial WIFI Module

Overview

ESP8266 offers a complete and self-contained Wi-Fi networking solution, allowing it to either host the application or to offload all Wi-Fi networking functions from another application processor.

When ESP8266 hosts the application, and when it is the only application processor in the device, it is able to boot up directly from an external flash. It has integrated cache to improve the performance of the system in such applications, and to minimize the memory requirements.

Alternately, serving as a Wi-Fi adapter, wireless internet access can be added to any microcontroller-based design with simple connectivity through UART interface or the CPU AHB bridge interface.

ESP8266 on-board processing and storage capabilities allow it to be integrated with the sensors and other application specific devices through its GPIOs with minimal development up-front and minimal loading during runtime. With its high degree of on-chip integration, which includes the antenna switch balun, power management converters, it requires minimal external circuitry, and the entire solution, including front-end module, is designed to occupy minimal PCB area.

Sophisticated system-level features include fast sleep/wake context switching for energy-efficient VoIP, adaptive radio biasing for low-power operation, advance signal processing, and spur cancellation and radio co-existence features for common cellular, Bluetooth, DDR, LVDS, LCD interference mitigation.

Go shopping [ESP8266 Serial WIFI Module(IM140905002)]

Electronic Characteristics

1.Current Consumption

The following current consumption is based on 3.3V supply, and 25℃ ambient, using internal regulators. Measurements are done at antenna port without SAW filter. All the transmitter’s measurements are based on 90% duty cycle, continuous transmit mode.

Mode	Min	Typ	Max	Unit
Transmit 802.11b, CCK 1Mbps, POUT=+19.5dBm		215		mA
Transmit 802.11b, CCK 11Mbps, POUT=+18.5dBm		197		mA
Transmit 802.11g, OFDM 54Mbps, POUT =+16dBm		145		mA
Transmit 802.11n, MCS7, POUT=+14dBm		135		mA
Receive 802.11b, packet length=1024 byte, -80dBm		60		mA
Receive 802.11g, packet length=1024 byte, -70dBm		60		mA
Receive 802.11n, packet length=1024 byte, -65dBm		62		mA
Standby		0.9		mA
Deep sleep		10		uA
Power save mode DTIM 1		1.2		mA
Power save mode DTIM 3		0.86		mA
Total shutdown		0.5		uA

2.RF Performance

The following are measured under room temperature conditions with 3.3V and 1.1V power supplies.

Description	Min	Typical	Max	Unit
Input frequency	2412		2484	MHz
Input impedance		50		Ω
Input reflection			-10	dB
Output power of PA for 72.2Mbps	14	15	16	dBm
Output power of PA for 11b mode	17.5	18.5	19.5	dBm
Sensitivity
CCK, 1Mbps		-98		dBm
CCK, 11Mbps		-91		dBm
6Mbps (1/2 BPSK)		-93		dBm
54Mbps (3/4 64-QAM)		-75		dBm
HT20, MCS7 (65Mbps, 72.2Mbps)		-71		dBm

Hardware

Schematic

Application Notes

• Smart power plugs
• Home automation
• Mesh network
• Industrial wireless control
• Baby monitors
• IP Cameras
• Sensor networks
• Wearable electronics
• Wi-Fi location-aware devices
• Security ID tags
• Wi-Fi position system beacons

Firmware & Software Development Kit

The application and firmware runs in on-chip ROM and SRAM, which loads the instructions during wake-up, through the SDIO interface, from the external flash. The firmware implements TCP/IP, the full 802.11 b/g/n/e/i WLAN MAC protocol and Wi-Fi Direct specification. It supports not only basic service set (BSS) operations under the distributed control function (DCF) but also P2P group operation compliant with the latest Wi-Fi P2P protocol. Low level protocol functions are handled automatically by ESP8266:

• RTS/CTS
• acknowledgement
• fragmentation and defragmentation
• aggregation
• frame encapsulation (802.11h/RFC 1042)
• utomatic beacon monitoring / scanning
• P2P Wi-Fi direct

Passive or active scanning, as well as P2P discovery procedure is performed autonomously once initiated by the appropriate command. Power management is handled with minimum host interaction to minimize active duty period.

Features:

• 802.11 b/g/n/d/e/i/k/r support;
• Wi-Fi Direct (P2P) support:
• P2P Discovery, P2P Group Owner mode, P2P Power Management
• Infrastructure BSS Station mode / P2P mode / softAP mode support;
• Hardware accelerators for CCMP (CBC-MAC, counter mode), TKIP (MIC, RC4), WAPI (SMS4), WEP (RC4), CRC;

• WPA/WPA2 PSK, and WPS driver;
• Additional 802.11i security features such as pre-authentication, and TSN;
• Open Interface for various upper layer authentication schemes over EAP such as TLS, PEAP, LEAP, SIM, AKA, or customer specific;
• 802.11n support (2.4GHz / 5GHz);
• Supports MIMO 11 and 21, STBC, A-MPDU and A-MSDU aggregation and 0.4s guard interval;
• WMM power save U-APSD;
• Multiple queue management to fully utilize traffic prioritization defined by 802.11e standard;
• UMA compliant and certified;
• 802.1h/RFC1042 frame encapsulation;
• Scattered DMA for optimal CPU off load on Zero Copy data transfer operations;
• Antenna diversity and selection (software managed hardware);
• Clock/power gating combined with 802.11-compliant power management dynamically adapted to curent connection condition providing minimal power consumption;
• Adaptive rate fallback algorithm sets the optimium transmission rate and Tx power based on actual SNR and packet loss information;
• Automatic retransmission and response on MAC to avoid packet discarding on slow host environment;
• Seamless roaming support;
• Configurable packet traffic arbitration (PTA) with dedicated slave processor based design provides flexible and exact timing Bluetooth co-existence supoport for a wide range of Bluetooth Chip vendors;
• Dual and single antenna Bluetooth co-existence support with optional simultaneous receive (Wi-Fi/Bluetooth) capability.

AT Commands

Format

• Baud rate at 57600
• x is the commands

Set	Inquiry	Test	Execute
AT+<x>=<…>	AT+<x>?	AT+<x>=?	AT+<x>
AT+CWMODE=<mode>	AT+CWMODE?	AT+CWMODE=?	-
Set the network mode	Check current mode	Return which modes supported	-

Commands

• carefully there are must be no any spaces between the " and IP address or port

Commands	Description	Type	Set/Execute	Inquiry	test	Parameters and Examples
AT	general test	basic	-	-	-	-
AT+RST	restart the module	basic	-	-	-	-
AT+GMR	check firmware version	basic	-	-	-	-
AT+CWMODE	wifi mode	wifi	AT+CWMODE=<mode>	AT+CWMODE?	AT+CWMODE=?	1= Sta, 2= AP, 3=both, Sta is the default mode of router, AP is a normal mode for devices
AT+CWJAP	join the AP	wifi	AT+ CWJAP =<ssid>,< pwd >	AT+ CWJAP?	-	ssid = ssid, pwd = wifi password
AT+CWLAP	list the AP	wifi	AT+CWLAP
AT+CWQAP	quit the AP	wifi	AT+CWQAP	-	AT+CWQAP=?
AT+ CWSAP	set the parameters of AP	wifi	AT+ CWSAP= <ssid>,<pwd>,<chl>, <ecn>	AT+ CWSAP?		ssid, pwd, chl = channel, ecn = encryption; eg. Connect to your router: AT+CWJAP="www.electrodragon.com","helloworld"; and check if connected: AT+CWJAP?
AT+CWLIF	check join devices' IP	wifi	AT+CWLIF	-	-
AT+ CIPSTATUS	get the connection status	TCP/IP	AT+ CIPSTATUS			<id>,<type>,<addr>,<port>,<tetype>= client or server mode
AT+CIPSTART	set up TCP or UDP connection	TCP/IP	1)single connection (+CIPMUX=0) AT+CIPSTART= <type>,<addr>,<port>; 2) multiple connection (+CIPMUX=1) AT+CIPSTART= <id><type>,<addr>, <port>	-	AT+CIPSTART=?	id = 0-4, type = TCP/UDP, addr = IP address, port= port; eg. Connect to another TCP server, set multiple connection first: AT+CIPMUX=1; connect: AT+CIPSTART=4,"TCP","X1.X2.X3.X4",9999
AT+CIPMODE	set data transmission mode	TCP/IP	AT+CIPMODE=<mode>	AT+CIPSEND?		0 not data mode, 1 data mode; return "Link is builded"
AT+CIPSEND	send data	TCP/IP	1)single connection(+CIPMUX=0) AT+CIPSEND=<length>; 2) multiple connection (+CIPMUX=1) AT+CIPSEND= <id>,<length>		AT+CIPSEND=?	eg. send data: AT+CIPSEND=4,15 and then enter the data.
AT+CIPCLOSE	close TCP or UDP connection	TCP/IP	AT+CIPCLOSE=<id> or AT+CIPCLOSE		AT+CIPCLOSE=?
AT+CIFSR	Get IP address	TCP/IP	AT+CIFSR		AT+ CIFSR=?
AT+ CIPMUX	set mutiple connection	TCP/IP	AT+ CIPMUX=<mode>	AT+ CIPMUX?		0 for single connection 1 for multiple connection
AT+ CIPSERVER	set as server	TCP/IP	AT+ CIPSERVER= <mode>[,<port> ]			mode 0 to close server mode, mode 1 to open; port = port; eg. turn on as a TCP server: AT+CIPSERVER=1,8888, check the self server IP address: AT+CIFSR=?
AT+ CIPSTO	Set the server timeout	AT+CIPSTO=<time>	AT+CIPSTO?		<time>0~28800 in second
+IPD	received data					For Single Connection mode(CIPMUX=0): + IPD, <len>: For Multi Connection mode(CIPMUX=1): + IPD, <id>, <len>: <data>

Download

File:ESP8266_Specifications_English.pdf File:ESP8266 Specifications(Chinese).pdf

Useful Link

Reference:

• https://nurdspace.nl/ESP8266
• http://www.electrodragon.com/w/Wi07c