ESP8266 WIFI MODULE: In this modern world, the Wi-Fi technology has removed the distances, in which the electronic devices are used, which are connected to the wireless Lan (WLAN) network, by using at 2.4 gigahertz or 5 gigahertz radio frequency bands. The Lan network provides the facility of password protection and also allows the device to use the network which is within the range of that device. In this advance technology different types of modules are used, which have different features. Here we would explain the ESP8266 WI-FI module is details but before explaining this types of module, first of all we would explain the brief history of Wi-Fi.
The history of WI-FI was started in 1985, when the united states FCC used the 900 MHZ frequency band without license. Because the frequency band of this technology was very low therefore in beginning, this technology was onlyassumed for home appliances such as microwave oven. After that, in 1991 the NCR and AT&T corporation invented a first wireless product that’s name was Wave Lan, which was used for cashier system. In this fragmented market the research was continued, finally the first WI- FI system was introduced in 1997, which was the prototype communication system.
ESP8266 WI-FI Module
The ESP8266 WI-FI module is basically, a complete WI-FI solution, which have self-contained operating system and integrated TCP/IP protocol stack that can be easily connect to the microcontroller for gaining the access to any Wi-Fi network This module has the capability of either to give or gain the applications and functions from other module or processor, mean’s that this also have the facility of hosting or uploading the functions and applications. For connecting this module to any WI-FI network, just up load the pre-programed program which is set in this module as firmware. This is very cost effective module with an ever growing and huge communication community.
This module has powerful storage and data processing capability therefore it can easily integrate with sensors and others processing units. This is high degree on chip integration device which has a very low PCB circuitry area. It is supported with IPSD for output applications and also interfaced with Bluetooth. This module does not require any external RF signal because it have self-contained calibrated signal. The ESP 8266 WI-FI module is shown in figure below
Pin Configuration of ESP 8266 WI-FI Module
The ESP8266 WI-FI module consist of two rows of eight pins. The pin configuration diagram is shown in figure below
According to the figure 2 the pin 1, which is GND the ground pin which is directly connected to the ground for power on this module. The pins 2 and 3, which are the GPIO 2 and GPIO 0, these pins decided in which mode the module would be start-up, in other words these are mode selected pins. The pins 4 and 5, which are RX and TX, these pin are used for communication purposes and program the module. The pin 6 which is CH_PD, it is called chip power down pin. The pin 7 which is RST pin and this pin is used for reset the module. The pin 8 which is VCC pin and is used to power on the module. The operating voltage of this module is 3.3 volts, which are directly connected to the ground pin(GND) and VCC pin.
Instruction Commands of ESP 8266 Module
The wireless WI-FI ESP 8266 module is drive through serial interfacing with Arduino or any type of modules. The standard AT commands are used for this purposes, which are almost twelve.
(1) AT: This type of command is used to test the startup function of WI-FI module. The response would be ok, against this command if everything is ok.
(2) AT+RST:This type of command is used for reset the WI-FI module when it is in working condition. The response would be ok, when reset the module.
(3)AT+GMR: This type of AT command is used to check the version of AT command and we used SDK version of AT command in this type of WI-FI module.
(4) AT+GSLP: This type of AT command is used to invoke the module from sleep mode, in other words this command is used for wake -up the module.
(5) ATE:This type of command is used for echo sound, means that, when this command is entered then the echo send back to the sender.
(6) AT+RESTORE: This type of command is used for restore factory setting means, when this command is entered then all the parameters are reset automatically.
(7) AT+UART: This type of command is used for set the UART configuration and writes the new configuration in flash means, it is used for setting the default parameters.
(8) AT+UART_CUR:This type of command is used for set the current UART configuration and does not write to the flash.
(9) AT+UART_DEF: This type of command is used for set the UART configuration and save it in flash.
(10) AT+SLEEP:This type of command is used to the set the module in sleep mode.
(11) AT+RFPOWER:This type of command is used for set the maximum value of power for ESP 8266 RXTF, but it is not precise.
(12) AT+RFVDD:This type of command is used for set the maximum value of power for ESP 8266 RXTX according to the VDD33.
Interfacing of ESP8266 Module with arduino
The ESP8266 WI-FI module cannot directly connect to the computer for connecting this with computer an interfacing device is must require. The interfacing device may be the microcontroller or Arduino board. By using the serial port of audio the ESP 8266 module can be connect to the computer. The Arduino board runs on 5 volts and ESP 8266 run on 3.3 volte. Before connection, first you have make sure the regulated required voltages. These voltages can regulate for TX/RX pins through the IC CD 4050 shown in figure.
Two serial ports are used for this connection, one serial port is used for the connection between Arduino and ESP 8266 for sending the command AT to ESP8266 and other one is used for the connection between Arduino and computer for typing the command AT on computer key board.
Applications of ESP 8266 in IOT(Internet of things)
- Internet of things is a network, that is used in our daily life, in which embedded and electronics are combined use. In this network a small computer is directly involved for controlling the home appliances such as light bulbs, fans, refrigerator and microwave oven etc. All these home appliances can be easily control through the WI-FI ESP8266 module and this system is called home automation system.
- It is used in security cameras for controlling and check the cameras positon at any time of a day.
- It is used in robotic arms for controlling the positon of arm automatically through the WI-FI network.
- It is used with temperature sensors for controlling the temperature automatically.
- It is used in quadcopters and drone attacks for checking the target through WI-FI