GT-38 Wireless Transceiver Module SI4438 433MHz - Serial Wireless Link

Description

The GT-38 wireless serial communication module is a new generation of multi-channel embedded wireless data transmission module. The wireless working frequency band is 433-458.5MHz, and multiple channels can be set. The stepping speed is 100KHz, and there are 255 channels in total. The module's maximum transmit power is 100mW (20dBm), the receiving sensitivity is -116dBm at 5000bps air baud rate, and the open distance can reach 1200m communication distance.
The module adopts stamp hole encapsulation and can be patch-welded. The module size is 26.7mm×12.9mm×6mm (including antenna cap, including spring antenna), which is convenient for customers to embed in the application system. The module has a PCB antenna holder ANT1. The user can use the 433M frequency band external antenna through the coaxial line. The module also has an antenna welding hole ANT2, which is convenient for the user to solder the spring antenna. The user can select one of the antennas according to the requirements of use.
The module contains MCU inside, the user does not need to program the module separately, and various transparent transmission modes can only send and receive serial port data, which is convenient to use. The module adopts a variety of serial port transparent transmission modes, and the user can select with AT commands according to the usage requirements. Four modes FU1, FU2, FU3, and FU4 have an average operating current of 3.6mA, 80μA, 16mA, and 16mA in idle state, and the maximum operating current is 100mA (at full power emission state).

Basic Specification

• Model GT-38
• Module size 26.7×12.9×6mm
• Chip Solution SI4438
• Working frequency band 433~458.5MHz
• Communication Interface UART 3.3V/5V TTL Level
• Antenna interface spring antenna / antenna socket
• Working voltage 3.2~5.5V
• Sleep current no sleep mode
• Communication level 3.3V/5V level
• Working humidity 10%~90%
• Transmit power 20dBm (MAX)
• Working temperature -25°C~+75°C
• Reference distance 1200m
• Storage temperature -40°C~+85°C

AT Commands

• Test communication AT
• Change the serial port baud rate command AT+Bxxxx Example: Set the module serial port baud rate to 19200bps, please send the module command "AT+B19200", the module returns "OK+B19200".
• Change the channel of wireless communication AT+Cxxx Example: Set the module to work on channel 21, please send the module command “AT+C021”, the module returns “OK+C021”. After exiting the command mode, the module operates on channel 21 and operates at 435.1 MHz.
• Change the module serial transmission mode AT+FUx Example: Send the module command "AT+FU1", the module returns "OK+FU1".
• Set the module's transmit power level AT+Px Example: Send the module command “AT+P5” and the module returns “OK+P5”. After exiting the command mode, the module transmit power is +11dBm.
• Get the single parameter of the module AT+Ry Example 1: Send the module command “AT+RB”. If the module returns “OK+B9600”, the serial port baud rate of the module is 9600bps. Example 2: The module command "AT+RC" is sent. If the module returns "OK+RC100", the communication channel of the module is queried to 100. Example 3: Send the module command “AT+RF”. If the module returns “OK+FU3”, the module is queried to work in serial port transparent transmission mode 3. Example 4: The module command "AT+RP" is sent. If the module returns "OK+RP: +20 dBm", the module's transmit power is queried to be +20 dBm.
• Get all the parameters of the module AT+RX Example: Send the module command “AT+RX”, the module returns “OK+FU3 OK+B9600 OK+C100 OK+RP:+20 dBm”.
• Set the data digits, check digits and stop bits of serial communication AT+Uxxx Example: To set the serial port format to 8-bit data bit, odd parity, 1 stop bit, please send the module command “AT+U8O1”, The module returns "OK+U8O1".
• Query module firmware version information AT+V
• Setting the sleep mode AT+SLEEP When the data is not transmitted wirelessly, in order to save power, the module command “AT+SLEEP” is sent, and the module returns “OK+SLEEP”. When it enters the AT setting state again, it automatically exits the sleep mode.
• Restore the serial port baud rate, communication channel, and serial port transparent transmission mode to the factory default values. AT+DEFAULT