Specification UART WiFi Module GWF-KM22 (2.4GHz 802.11 b/g/n) Ver: 1.
Contents 1. Introduction............................................................................................................................................................... 1 1.1 Profile................................................................................................................................................................1 1.2 Features.............................................................................................................................................
Figures and tables Table 1-1 General Specification.................................................................................................................................. 3 Table 1-2 Pin configuration......................................................................................................................................... 5 Table 1-3 Absolute Max Rating...................................................................................................................................
1. Introduction 1.1 Profile The GWF-KM22 module operates in 2.4GHz ISM frequency band with low power consumption; it applies a highly integrated MAC/BBP in the MT7681 chipset, support IEEE的802.11b/g/n standards with 1T1R technology. This module supports TCP/IP ， UDP protocol ， its low cost and low power consumption, easy using characteristics make the wireless connection become easy and reliable. The single side components mounted module provide 1 UART interface and 4 GPIO ports.
1.3 Block diagram Fig.
1.4 Outline Fig. 1- 2 Outline reference picture 1.5 Specification Table1 1–1 General Specification Protocol and interface WiFi Protocol IEEE 802.
LED display Link/Activity display Memory size External SPI Flash 4Mbit WiFi Features WiFi mode Client / Soft AP mode Encryption WPA2-PSK，WEP ( more will be available later) WiFi RF Characteristics Frequency ISM band, 2412~2462MHz. 802.11b (CCK) 11Mbps: 19.5+/-1dBm Tx power （Peak value） 802.11g (OFDM) 54Mbps: 21.5+/-1dBm 802.11n(HT20@MCS7),20.5+/-1dBm Rx sensitivity 802.11b: -86+/-1dBm; 802.11g: -72+/-1dBm, 802.11n (HT20), -68+/-1dBm; Operation Voltage and Current (Typical) Power supply 3.
Operating humidity 20% to 80% Physical Size 30*18mm Weight 2.4g 1.6 Pinout configuration Shield Case D LE Shield Case Fig.
3 VCC 3.3V 4 RXD UART_RXD(UART Receive data) 5 TXD UART_TXD(UART transmit data) 6 GPIO3 GPIO3 7 GPIO2 GPIO2 8 GPIO1 GPIO1 9 GPIO0 GPIO0 10 NC Not Connection Notes: 1. GPIO0〜3 can be pulled up to low or high 2. For the time being only UART/GPIO supported 3. Pin 10 must ben’t connected 4、GPIO1 has been reserved for a AT command mode switching, high level is the AT command mode, low level is pure data model 1.
2. Reminds to hardware design 2.1 Application The module is designed with an UART interface, it support TCP/IP protocol, users can use the UART port to transfer data via WiFi connection to other internet devices. Fig. 2-1 To use external MCU 2.2 GPIO Descriptions The KM22 module designed with 4 GPIO port , the fastest interrupt request time is about 1ms。 Each GPIO port can be individually configured as an input or output via software.
purpose; please specify the requirement when ordering, so that the onboard LED can be removed during production. 2.2.1 LED Display When an external LED to be used, a recommended connection shows as below: Fig. 2- 3 Reference design for external LED connection * the 470 ohm resistor can be changed to a value depends on the brightness of the LED. 2.
2.4 Power supply Table 2- 2 pin configuration pin Symbol Description 2 GND Ground 3 3.3VD 3.3Vpower input Since the module needs clean and low ripple 3.3V DC power supply, please properly design the power supply to this module, otherwise the RF performance of the module might be deteriorated. 2.5 RF output A、onboard antenna Fig.
2.6 Dimensions Shield Case D LE Shield Case Fig. 2-6 Dimensions 2.7 Clear place to use the module The following drawing shows a recommended footprint which can be a reference for a main PCB design. The clear space requirement for onboard antenna is suit for either pin header or semi-holes connection application.
Shield Case D LE Shield Case Metallic Clear Area Fig. 2-7 Note： Clear space needed Pin 10 must ben’t connected 3.Software descriptions Right now, to develop customized application, the SDK software pack provided by the chipset manufacturer MTK is recommended to use. Other kind of software supported is not available yet. 3.1 AT command This module applies the chipset MT7681, it has its own internal MCU which can be used to fulfill some sort of software functions.
Command Parameters Descriptions Ver none Display ver Reboot none Reboot Default none Load default Smtconn none Start smart connection mode Conn_AP -sSSID -pPassword Connect ap Uart_Wifi -n(0/1) -m(0/1) -i(ip-addr) -l(local port) -r(remort port) Open TCP/UDP Server/Client Mac none Display the device MAC GPIO -p(pin) -w(0/1) -r(0/1) Write/Read GPIO WMode -w(0/1) Switch to AP/STA mode Puredata none Enter the pure data mode 4.
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2. Changes or modifications not expressly approved by the party responsible for compliance could void t he user's authority to operate the equipment. The devices must be installed and used in strict accordance with the manufacturer's instructions as desc ribed in the user documentation that comes with the product.
