Introduction
The ESP8266 WiFi Module is a self-contained SOC with integrated TCP/IP protocol stack that can give any microcontroller access to your WiFi network. The ESP8266 is capable of either hosting an application or offloading all Wi-Fi networking functions from another application processor. Each ESP8266 module comes pre-programmed with an AT command set firmware, which means that you can simply connect this to evive and get about as much WiFi-ability as a WiFi Shield offers.
Features
- 11 b/g/n
- Wi-Fi Direct (P2P), soft-AP
- Integrated TCP/IP protocol stack
- Integrated TR switch, balun, LNA, power amplifier and matching network
- Integrated PLLs, regulators, DCXO and power management units
- +19.5dBm output power in 802.11b mode
- Power down leakage current of <10uA
- Integrated low power 32-bit CPU could be used as application processor
- SDIO 1.1 / 2.0, SPI, UART
- STBC, 1×1 MIMO, 2×1 MIMO
- A-MPDU & A-MSDU aggregation & 0.4ms guard interval
- Wake up and transmit packets in < 2ms
- Standby power consumption of < 1.0mW (DTIM3)
evive has dedicated WiFi headers which require you to just connect the ESP8266 WiFi module. Communication between evive and the WiFi module takes place via serial port 3.
ESP8266 AT Command Set
Below is the table showing the AT Command Set for the ESP8266 WiFi Module:
| Function | AT Command | Responce |
|---|---|---|
| Working | AT | OK |
| Restart | AT+RST | OK [System Ready, Vendor:www.ai-thinker.com] |
| Firmware version | AT+GMR | AT+GMR 0018000902 OK |
| List Access Points | AT+CWLAP | AT+CWLAP +CWLAP:(4,"RochefortSurLac",38,"70:62:b8:6f:6d:58",1) +CWLAP:(4,"LiliPad2.4",-83,"f8:7b:8c:1e:7c:6d",1) OK |
| Join Access Point | AT+CWJAP? AT+CWJAP="SSID","Password" | Query AT+CWJAP? +CWJAP:"RochefortSurLac" OK |
| Quit Access Point | AT+CWQAP=? AT+CWQAP | Query OK |
| Get IP Address | AT+CIFSR | AT+CIFSR 192.168.0.105 OK |
| Set Parameters of Access Point | AT+ CWSAP? AT+ CWSAP= | Query ssid, pwd chl = channel, ecn = encryption |
| WiFi Mode | AT+CWMODE? AT+CWMODE=1 AT+CWMODE=2 AT+CWMODE=3 | Query STA AP BOTH |
| Set up TCP or UDP connection | AT+CIPSTART=? (CIPMUX=0) AT+CIPSTART = (CIPMUX=1) AT+CIPSTART= (CIPMUX=0) AT+CIPSTART = (CIPMUX=1) AT+CIPSTART= | Query id = 0-4, type = TCP/UDP, addr = IP address, port= port |
| TCP/UDP Connections | AT+ CIPMUX? AT+ CIPMUX=0 AT+ CIPMUX=1 | Query Single Multiple |
| Check join devices' IP | AT+CWLIF | |
| TCP/IP Connection Status | AT+CIPSTATUS | AT+CIPSTATUS? no this fun |
| Send TCP/IP data | (CIPMUX=0) AT+CIPSEND= (CIPMUX=1) AT+CIPSEND= | |
| Close TCP / UDP connection | AT+CIPCLOSE= | |
| Set as server | AT+ CIPSERVER= | mode 0 to close server mode; mode 1 to open; port = port |
| Set the server timeout | AT+CIPSTO? AT+CIPSTO= | Query |
| Baud Rate* | AT+CIOBAUD? Supported: 9600, 19200, 38400, 74880, 115200, 230400, 460800, 921600 | Query AT+CIOBAUD? +CIOBAUD:9600 OK |
| Check IP address | AT+CIFSR | AT+CIFSR 192.168.0.106 OK |
| Firmware Upgrade (from Cloud) | AT+CIUPDATE | +CIPUPDATE:1 found server +CIPUPDATE:2 connect server +CIPUPDATE:3 got edition +CIPUPDATE:4 start update |
| Received data | +IPD | (CIPMUX=0): + IPD, (CIPMUX=1): + IPD, |
| Watchdog Enable* | AT+CSYSWDTENABLE | Watchdog, auto restart when program errors occur: enable |
| Watchdog Disable* | AT+CSYSWDTDISABLE | Watchdog, auto restart when program errors occur: disable |
Example to use AT commands
Below is the Arduino IDE sketch showing how to configure the ESP8266 WiFi Module using AT Commands:
