TXD: Send side, generally expressed as their transmitter, RXD normal communication must be connected to another device.
RXD: the receiver, generally designated himself on the receiving end, Normal communication TXD must be connected to another device.
When normal communication itself TXD RXD always connected device!
Since the resumption of spontaneous: RXD when normal communication TXD connected to other devices, so if you want to receive data sent by itself as the name suggests, is to receive the data they transmit their own, that is directly connected to its own TXD RXD, used and receive test itself is it normal, Is the fastest and easiest way to test when there is a problem to do the first test to determine if your problem . Also known as the loopback test.
1.2 level logic:
TTL level: usually binary data representation, provisions equivalent to + 5V logic 1,0V equivalent to a logic 0, called TTL signal system, is positive logic
RS232 level: the use of -12V to -3V, equivalent to a logic 0, + 3V to + 12V logic level equivalent to logic 1, negative logic
1.3 Product Features:
1 Core module uses HC-05 from the module, including the interface leads VCC, GND, TXD, RXD, KEY pin Bluetooth connection status leads to foot STATE , Low output is not connected, the connection after a high output
2, led Indicates Bluetooth connection status, Bluetooth connectivity means no flash, slow flash that enter the AT mode, double flash indicates Bluetooth connection and open ports
3, the bottom plate set Anti-reverse diode With 3.3V LDO, Input voltage 3.6 ~ 6V, when the unpaired current is about 30mA, paired about 10mA, Input voltage Prohibit more than 7V!
4, interface level 3.3V, can be directly connected to various microcontrollers 51, AVR, PIC, ARM, MSP430, etc. , 5V MCU also can be connected directly, without MAX232 MAX232 can not go through!
5, Open to the effective distance of 10 meters (power rating of CLASS 2), More than 10 meters are possible, but do not make this connection the of distance
6, when the pair later Full duplex serial port Use, without having to know any Bluetooth protocol support 8 data bits, 1 stop bit, parity can be set Communication format, which is the most common communication format does not support other formats.
7, can be pulled 34 feet into the AT command mode setting parameters and query information
8, compact 3.57cm * 1.52cm , Chip production Ensure the placement . Transparent shrink tube and sleeve, dust and beautiful, and there is a certain anti-static capabilities.
9, can be selected via AT command as master or slave mode, can be connected to the specified device through AT commands
10, support from inter-standard baud rate of 4800bps ~ 1382400bps
1.4 Product use:
After pairing only as a fixed baud rate of the serial port can be used in the same, so long as it is fixed baud, 8 data bits, no parity communication format of the serial devices can be directly replace the wired serial port without the need for modify the program. Such as data acquisition, smart car, serial printers, and other outdoor dot matrix screen control.
Paired with a computer: Fit between computers and devices via Bluetooth serial communication, using the same method and serial
Paired with the phone: Fit between your phone with a Bluetooth device via serial communications, use the same serial port
Paired with a Bluetooth host: For two devices directly via Bluetooth serial communication, such as between the microcontroller and microcontroller serial cable with microchips, etc., use the same serial port
Baud rate conversion, because the receiver and the sender can choose their own baud rate, in a small amount of data when you can use the device as a baud rate of transformation.
2.1 How to connect the Bluetooth module with the computer From the mode is active
The following order with the computer with Bluetooth paired with an example:
First to pass through the Bluetooth module power, this time led blinks to turn my bluetooth location, click Search for devices within range,
The system will search for Bluetooth devices, the default device name linvor As modified name was modified name, such as jiaelectron Double-click or right click and select Add a Bluetooth device,
Enter a passcode The default is 1234 ,
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