Sumind Bluetooth FM Transmitter (Model BT70B) User Manual
Enhanced Wireless Radio Adapter for In-Car Audio and Charging
1. Introduction
This manual provides detailed instructions for the safe and efficient use of your Sumind Bluetooth FM Transmitter, Model BT70B. This device allows you to stream audio wirelessly from your Bluetooth-enabled devices to your car's FM radio, make hands-free calls, and charge multiple devices simultaneously.
Figure 1: Sumind Bluetooth FM Transmitter (Model BT70B)
2. Safety Information
Please read all safety warnings and instructions before using this product to prevent injury or damage. Keep this manual for future reference.
Do not expose the device to extreme temperatures, direct sunlight, or moisture.
Avoid dropping or subjecting the device to strong impacts.
Do not disassemble, repair, or modify the device. This will void the warranty.
Ensure proper ventilation around the device during use.
Always prioritize driving safety. Do not operate the device in a way that distracts you from the road.
3. Product Overview
Familiarize yourself with the components of your Sumind Bluetooth FM Transmitter:
Key Components:
Display Screen: 1.7-inch LCD for showing frequency, song name, incoming calls, and car battery voltage.
Frequency Up/Down Buttons (CH+/CH-): Adjust FM transmission frequency.
Multifunction Button (Volume/Call): Rotate for volume, press for play/pause, answer/end calls, long press for voice assistant.
TF Card Slot: For playing MP3/WMA audio files from a Micro SD card (up to 32GB).
Smart 2.4A USB Charging Port: Standard USB charging port.
QC3.0 USB Charging Port: Quick Charge 3.0 port for faster charging of compatible devices.
Flexible Hose: Adjustable gooseneck for optimal viewing angle.
Power Contactor: Plugs into the car's 12-24V socket.
AUX Input/Output: 3.5mm audio jack for direct audio connection.
4. Setup Instructions
4.1 Initial Connection
Insert the FM transmitter into your car's 12V-24V cigarette lighter socket. The device will power on automatically, and the LCD screen will display the car battery voltage for a few seconds before showing the FM frequency.
Find an empty FM frequency on your car radio. Choose a frequency that has no active broadcast to minimize interference.
Adjust the FM frequency on the transmitter to match the empty frequency on your car radio. Use the CH+ and CH- buttons to change the frequency.
4.2 Bluetooth Pairing
On your mobile device, enable Bluetooth and search for available devices.
Select the device named "BT70B" from the list to pair.
Once paired, the transmitter's display will indicate a successful connection, and you can now stream audio from your phone.
4.3 Media Playback Options
The Sumind BT70B offers multiple ways to play audio:
Bluetooth: Stream audio wirelessly from your paired smartphone or tablet.
TF Card: Insert a Micro SD card (FAT format, up to 32GB) into the TF card slot. The device will automatically detect and play MP3/WMA files.
AUX Input: Connect your audio device directly using a 3.5mm audio cable to the AUX port.
Figure 2: Multiple Audio Playback Sources
5. Operating Instructions
5.1 Audio Playback
Play/Pause: Press the Multifunction Button (center knob) to play or pause the current track.
Next/Previous Track: Use the Previous Track and Next Track buttons on the device to skip tracks.
Volume Adjustment: Rotate the Multifunction Button clockwise to increase volume, counter-clockwise to decrease volume.
5.2 Hands-Free Calling
The built-in microphone and CVC noise cancellation technology enable clear hands-free communication.
Answer/End Call: Press the Multifunction Button once to answer an incoming call or end an ongoing call.
Reject Call: Long press the Multifunction Button to reject an incoming call.
Redial: Double-press the Multifunction Button to redial the last number.
Activate Voice Assistant: Long press the Multifunction Button for 3 seconds to activate your phone's voice assistant (e.g., Siri, Google Assistant).
Figure 3: Hands-Free Calling Feature
5.3 Charging Devices
The transmitter features dual USB ports for charging your mobile devices:
QC3.0 Port: Provides fast charging for Quick Charge compatible devices.
Smart 2.4A Port: Delivers optimized charging for other USB-powered devices.
Figure 4: Dual USB Charging Ports
5.4 LCD Display Functions
The 1.7-inch LCD display provides useful information:
Displays the current FM transmission frequency.
Shows the song name during media playback (if supported by the audio source).
Indicates incoming phone numbers during calls.
Monitors your car's battery voltage when the car starts.
Figure 5: 1.7 Inch LCD Display
5.5 Turning Off the FM Transmitter
To turn off the FM transmission and Bluetooth functions while keeping the charging function active, long press the Next Track button for 5 seconds.
6. Maintenance
Clean the device with a soft, dry cloth. Do not use liquids or abrasive cleaners.
Keep the device free from dust and debris to ensure optimal performance of ports and buttons.
Store the device in a cool, dry place when not in use.
7. Troubleshooting
No Power: Ensure the device is securely plugged into the car's 12V-24V socket. Check the car's fuse for the cigarette lighter.
Static/Poor Audio Quality: Try changing the FM frequency on both the transmitter and your car radio to an unused channel. Ensure the volume on your phone and car radio are adjusted appropriately.
Bluetooth Disconnection: Re-pair the device with your phone. Ensure no other Bluetooth devices are causing interference.
Charging Issues: Verify that the charging cable is properly connected to both the transmitter and your device. Ensure your device is compatible with the QC3.0 or 2.4A charging standards.
8. Specifications
Feature
Detail
Model Number
BT70B
Input Voltage
12-24 Volt
USB Output 1
QC3.0 (Quick Charge)
USB Output 2
Smart 2.4A
Display Screen
1.7 Inch LCD
Bluetooth Version
V4.2 + EDR
Supported Audio Formats
MP3/WMA
TF Card Support
Up to 32GB (FAT format)
Special Features
Built-In Microphone, CVC Noise Cancellation, A2DP, AUX Input/Output
Product Dimensions
3.09 x 2.24 x 8.41 inches
Item Weight
3.35 ounces
9. Official Product Video
Video: Overview of the Sumind Bluetooth FM Transmitter's features and functionality.
10. Warranty and Support
For warranty information and customer support, please refer to the product packaging or contact Sumind customer service directly. General safety warnings about battery handling, electronic device usage, and Bluetooth technology may apply.
