User Manual: Bluetooth 5.2 FM Transmitter for Car

1. Product Overview

The eppfun S-23 Bluetooth 5.2 FM Transmitter is designed to enhance your in-car audio experience. It allows you to stream music from your Bluetooth-enabled devices, make hands-free calls, and play audio from TF cards or via AUX output, all through your car's FM radio system or directly to its AUX input.

Key features include:

• Bluetooth 5.2 Connectivity: Ensures stable and clear audio transmission with reduced interference.
• TF Card Playback: Supports multiple audio formats including MP3, WMA, APE, FLAC, and WAV.
• AUX Out Functionality: Provides a direct wired connection to your car's audio system for superior sound quality, bypassing FM modulation.
• Hands-Free Calling: Integrated microphone for clear communication during calls.
• Power-Off Memory: Automatically saves playback frequency, volume, and track position upon power-off.
• Compact Design: Features a compact size with adhesive fixation for flexible placement.

Figure 1: Main view of the eppfun S-23 Bluetooth FM Transmitter, showing its circular display unit and USB power cable.

2. Product Components and Diagram

Familiarize yourself with the various parts of your eppfun S-23 device:

Figure 2: Detailed diagram of the eppfun S-23, highlighting its components: Previous song button, Working condition indicator, TF card holder, Microphone hole, Multi-Function Buttons, USB powered cable, Next song button, AUX OUT port, and Spring wire.

• Multi-Function Button: Used for power on/off, play/pause, answer/end calls.
• Previous/Next Song Buttons: For track navigation.
• TF Card Holder: Slot for inserting a TF (microSD) card for music playback.
• Microphone Hole: Built-in microphone for hands-free calling.
• AUX OUT Port: 3.5mm audio jack for direct connection to car's AUX input.
• USB Powered Cable: Connects to a USB power source (e.g., car charger, USB port).
• Spring Wire: Flexible coiled cable for convenient placement.

3. Setup Instructions

1. Power Connection: Connect the USB powered cable of the S-23 to a suitable USB power source in your car (e.g., car charger adapter, car's USB port). The device will power on automatically.
2. FM Frequency Tuning (for FM transmission):
   • Tune your car's FM radio to an empty frequency (one with no strong broadcast signal).
   • Adjust the S-23's FM frequency to match your car's radio. Refer to the operating instructions for frequency adjustment.
3. Bluetooth Pairing:
   • On your mobile device, enable Bluetooth and search for available devices.
   • Select "S-23" from the list to pair. A voice prompt or indicator light will confirm successful connection.
   • The device will automatically reconnect to "S-23" on subsequent power-ons if Bluetooth is enabled on your paired device.
4. AUX Out Connection (Optional): If your car has an AUX input, you can connect the S-23 directly using a 3.5mm audio cable (not included) to the AUX OUT port on the device. This bypasses FM transmission for clearer audio.
5. Adhesive Fixation: Use the provided 3M adhesive to secure the S-23 to a convenient location on your dashboard or console. Ensure the surface is clean and dry before applying.
   

   Figure 3: The compact design of the S-23, demonstrating its adhesive fixation for flexible mounting in a vehicle.

4. Operating Instructions

4.1 Music Playback

1. Bluetooth Audio Streaming:
   • Once paired, open your music player on your mobile device and start playback. Audio will be transmitted to the S-23.
   • Use the Previous/Next song buttons on the S-23 to navigate tracks.
   • Press the Multi-Function Button to play or pause music.
2. TF Card Playback:
   • Insert a TF card (microSD card) containing MP3, WMA, APE, FLAC, or WAV audio files into the TF card holder.
   • The device will automatically switch to TF card playback mode.
   • Use the Previous/Next song buttons to navigate tracks and the Multi-Function Button to play/pause.
   • Note: TF card playback takes priority over Bluetooth. If a TF card is inserted, it will play from the card.
     

     Figure 4: The S-23 device with a TF card inserted, illustrating its capability for direct music playback from a memory card.

3. Simultaneous Device Connection: The S-23 supports simultaneous connection of two mobile devices, allowing you to freely switch the playback audio source without delay.
   

   Figure 5: The S-23 connected to two mobile devices simultaneously, enabling seamless switching between audio sources for music and navigation.

4.2 Hands-Free Calling

• Answer Call: When an incoming call rings, press the Multi-Function Button once to answer.
• End Call: During a call, press the Multi-Function Button once to end the call.
• Reject Call: When an incoming call rings, press and hold the Multi-Function Button for 2 seconds to reject the call.
• Redial Last Number: Double-press the Multi-Function Button to redial the last dialed number.

5. Maintenance

• Keep the device dry. Avoid exposure to moisture or liquids.
• Clean the device with a soft, dry cloth. Do not use abrasive cleaners or solvents.
• Store the device in a cool, dry place when not in use.
• Avoid extreme temperatures, as this can shorten the lifespan of electronic components.

6. Troubleshooting

7. Specifications

8. Warranty and Support

For warranty information and technical support, please refer to the official eppfun website or contact their customer service directly. Keep your purchase receipt for warranty claims.

For further assistance, you may visit the eppfun store on Amazon: eppfun Amazon Store.