Connection and Practical Application of Arduino and KT6368A Bluetooth Chip: Improve Development Efficiency with Development Kits

In the fields of the Internet of Things and embedded development, Bluetooth chips are crucial components for wireless communication. The KT6368A is a low - cost pure - data chip that supports Bluetooth 5.1 dual - mode (BLE + SPP) and is widely used in various smart devices. This article will detail how to connect the KT6368A to Arduino and configure and communicate with it through AT commands. At the same time, it is recommended to use development kits and FAQs to quickly use and debug code, improving development efficiency.

I. Overview of the KT6368A Bluetooth Chip

The KT6368A is a pure - data transparent - transmission chip that supports the Bluetooth 5.1 protocol and has the following characteristics:

• Dual - mode Support: It supports both BLE and SPP dual - modes, but only one mode can be used at a time.

• Size and Cost: It has an ultra - small SOP8 package and extremely low cost.

• Communication Interface: It supports UART serial communication with a default baud rate of 115200.

• Instruction Configuration: It has a built - in AT command set, allowing configuration of name, address, baud rate, UUID, etc.

• Power Consumption Performance: Its low - power version, KT6328A, has an average current as low as 100μA.

II. Connection between Arduino and KT6368A Bluetooth Chip

Required Materials

• Arduino development board (such as Arduino Uno).

• KT6368A chip or module (can be designed independently or purchased as a finished module).

• 3.3V regulated power supply (the operating voltage of KT6368A ranges from 2.2V to 3.4V).

• Several Dupont wires.

• USB - to - TTL module (such as CH340G, for debugging).

Wiring Method

Precautions

• If Arduino has a 5V level, a 1kΩ resistor must be connected in series on the TX/RX lines.

• A 10kΩ pull - down resistor must be connected to Pin2 to GND.

• The antenna pin (Pin4) needs to be connected to an antenna or a π - type matching circuit should be reserved.

III. Configuration of the KT6368A Bluetooth Chip

The KT6368A supports a rich set of AT commands that can be configured through the serial port. The following are examples of common commands:

1. Set Bluetooth Name and Address

arduino

// Set the BLE name to "MyDevice"
Serial.println("AT+BMMyDevice\r\n");

// Set the BLE MAC address
Serial.println("AT+BN112233445566\r\n");

// Set the SPP name
Serial.println("AT+BDMySPP\r\n");

2. Set Baud Rate

arduino

// Set the baud rate to 9600
Serial.println("AT+CT01\r\n");
// Reset to make the settings take effect
Serial.println("AT+CZ\r\n");

3. Query Current Configuration

arduino

Serial.println("AT+TM\r\n"); // Query the BLE name
Serial.println("AT+TN\r\n"); // Query the BLE address
Serial.println("AT+QT\r\n"); // Query the current baud rate

4. Restore Factory Settings

arduino

Serial.println("AT+CW\r\n");

Tip: Using development kits and FAQs can quickly use and debug code, improving development efficiency.

IV. Implement Bluetooth Transparent Transmission Communication

BLE Mode Transparent Transmission Example (Tested with LightBlue App)

1. Use the AT command to enable BLE mode: AT+B401\r\n

2. Open LightBlue on the mobile phone, search for and connect to the device named "KT6368A - BLE".

3. Find the FFF1 characteristic and enable Notify.

4. Data sent by Arduino through the serial port will be automatically transmitted to the mobile phone.

Arduino Code Example (Simple Transparent Transmission)

arduino

void setup() {
  Serial.begin(115200); // Serial port for communication with KT6368A
  Serial1.begin(115200); // Serial port for debugging with the computer
}

void loop() {
  if (Serial.available()) {
    char c = Serial.read();
    Serial1.print(c); // Forward to the computer serial monitor
  }
  if (Serial1.available()) {
    char c = Serial1.read();
    Serial.print(c); // Forward to KT6368A
  }
}

V. Practical Experience and Key Points

1. Stable Power Supply: Never power it directly from Arduino's GPIO. An LDO must be used to provide 3.3V power.

2. Crystal Oscillator Selection: A 24MHz, 10ppm, 12pF - loaded crystal oscillator must be used, otherwise, connection will not be possible.

3. First - power - on Waiting: The chip requires 2.5 seconds for calibration during the first startup, and about 500ms for subsequent startups.

4. Command Format: AT commands must start with AT + and end with \r\n.

5. Device Search Issue: If the device cannot be searched, check if the crystal oscillator frequency deviation is within ±20kHz.

6. Connection Stability: If the connection is unstable, check if there is metal shielding or green oil covering around the antenna.

VI. Conclusion

The KT6368A is a highly cost - effective Bluetooth transparent - transmission chip, especially suitable for applications that are cost - sensitive and require dual - mode Bluetooth. Through the introduction in this article, it is believed that you have mastered the basic connection and configuration methods between it and Arduino. If you encounter code debugging or logical problems during development, it is recommended to use development kits and FAQs to quickly use and debug code, improving development efficiency.

Tags: #KT6368A Bluetooth Chip #Arduino #Bluetooth Transparent Transmission #IoT Development #Embedded Development