Design with KCX_BT_EMITTER to Bluetooth Speaker/Headphones in Cirkit DesignerThe KCX_BT_EMITTER is a compact and efficient Bluetooth audio transmitter module designed to enable devices to wirelessly stream audio to Bluetooth-enabled speakers or headphones. This module is ideal for applications where audio needs to be transmitted without the constraints of physical connections, such as in home audio systems, portable media players, or DIY electronics projects.
This circuit is a portable Bluetooth audio system powered by a Li-ion battery. It includes a Bluetooth audio receiver that sends audio signals to a 5V amplifier, which then drives a speaker and a tweeter. The system is powered through a battery charger and controlled by a push switch.
Open Project in Cirkit Designer
This circuit is a Bluetooth-enabled audio system powered by a rechargeable 18650 Li-ion battery. It includes a TP4056 module for battery charging and protection, a PAM8403 amplifier with volume control to drive two loudspeakers, and a Bluetooth audio receiver to wirelessly receive audio signals.
Open Project in Cirkit Designer
This circuit is designed to function as a Bluetooth-controlled speaker system using an Arduino UNO as the central controller. The Arduino is connected to a Bluetooth Mate Gold module for wireless communication and a speaker for audio output. The Arduino's digital pins D0 and D1 are used for RX and TX communication with the Bluetooth module, while pin D9 is configured to drive the speaker.
Open Project in Cirkit Designer
This circuit is a Bluetooth-enabled audio system with a microphone input. It uses a 5V Bluetooth Audio Receiver to receive audio signals wirelessly, which are then amplified by a PAM8403 amplifier before being output to a loudspeaker. Additionally, a condenser microphone is connected to the amplifier, allowing for audio input, and an Arduino UNO is present for potential control or further expansion, although it currently has no active code for operation.
Open Project in Cirkit DesignerThe KCX_BT_EMITTER module is designed for ease of use and compatibility with a wide range of devices. Below are its key technical specifications:
| Parameter | Value |
|---|---|
| Bluetooth Version | 5.0 |
| Operating Voltage | 5V DC |
| Current Consumption | ≤ 40mA |
| Transmission Distance | Up to 10 meters (line of sight) |
| Audio Format Support | SBC, AAC |
| Dimensions | 30mm x 20mm x 5mm |
| Operating Temperature | -20°C to 70°C |
The KCX_BT_EMITTER module has a simple pinout for easy integration into circuits. Below is the pin configuration:
| Pin | Name | Description |
|---|---|---|
| 1 | VCC | Power supply input (5V DC) |
| 2 | GND | Ground connection |
| 3 | TXD | UART Transmit pin for serial communication |
| 4 | RXD | UART Receive pin for serial communication |
| 5 | AUDIO_L | Left audio channel input |
| 6 | AUDIO_R | Right audio channel input |
| 7 | KEY | Pairing button input (active low) |
| 8 | LED | Status indicator output (connect to an LED if needed) |
VCC pin to a 5V DC power source and the GND pin to ground.AUDIO_L and AUDIO_R pins to the left and right audio output of your device (e.g., a media player or audio amplifier).KEY pin and ground. Pressing this button will put the module into pairing mode.LED pin can be connected to an LED (with a current-limiting resistor) to indicate the module's status (e.g., pairing, connected).TXD and RXD pins for UART communication if you need to configure the module or monitor its status.The KCX_BT_EMITTER can be connected to an Arduino UNO for additional control or monitoring. Below is an example of how to configure the module using Arduino:
| KCX_BT_EMITTER Pin | Arduino UNO Pin |
|---|---|
| VCC | 5V |
| GND | GND |
| TXD | Pin 10 (RX) |
| RXD | Pin 11 (TX) |
| KEY | Digital Pin 2 |
| LED | Digital Pin 13 |
// Example code to control the KCX_BT_EMITTER module with an Arduino UNO
// This code configures the module and monitors its status via UART.
#include <SoftwareSerial.h>
// Define RX and TX pins for SoftwareSerial
SoftwareSerial BTSerial(10, 11); // RX = Pin 10, TX = Pin 11
// Define the KEY and LED pins
const int keyPin = 2; // Pin connected to the KEY pin of the module
const int ledPin = 13; // Pin connected to the LED pin of the module
void setup() {
// Initialize serial communication
Serial.begin(9600); // For debugging via Serial Monitor
BTSerial.begin(9600); // For communication with the KCX_BT_EMITTER
// Configure pins
pinMode(keyPin, OUTPUT);
pinMode(ledPin, OUTPUT);
// Set initial states
digitalWrite(keyPin, HIGH); // Ensure the module is not in pairing mode
digitalWrite(ledPin, LOW); // Turn off the status LED
}
void loop() {
// Example: Put the module into pairing mode when a command is received
if (Serial.available()) {
char command = Serial.read();
if (command == 'P') { // 'P' for Pairing
Serial.println("Entering pairing mode...");
digitalWrite(keyPin, LOW); // Activate pairing mode
delay(2000); // Hold for 2 seconds
digitalWrite(keyPin, HIGH); // Exit pairing mode
}
}
// Monitor the module's status via UART
if (BTSerial.available()) {
char status = BTSerial.read();
Serial.print("Module Status: ");
Serial.println(status);
}
}
No Audio Output
AUDIO_L and AUDIO_R pins are properly connected to the audio source.Bluetooth Device Not Pairing
KEY pin).Intermittent Audio or Noise
LED Not Working
LED pin and the LED (including the current-limiting resistor).Q: Can the KCX_BT_EMITTER transmit audio from a microphone?
A: Yes, as long as the microphone's output is amplified to line-level signals compatible with the AUDIO_L and AUDIO_R inputs.
Q: What is the default pairing name of the module?
A: The default pairing name is typically "BT_EMITTER," but this may vary depending on the manufacturer.
Q: Can I use this module with a battery-powered device?
A: Yes, as long as the battery provides a stable 5V DC output. A voltage regulator may be required for higher voltage batteries.
Q: Is it possible to change the Bluetooth name or PIN?
A: This depends on the specific firmware of the module. If supported, you can use the UART interface to configure these settings.