Introduction
This manual provides comprehensive instructions for the installation, operation, and maintenance of your FEICHAO Flysky FS-BS4 Receiver. Please read this manual thoroughly before using the product to ensure correct setup and optimal performance. The FS-BS4 receiver features a Gyro Stabilization System and is designed for use with compatible Flysky remote controls, specifically the FS-GT5.
Product Overview
The FS-BS4 is a 4-channel 2.4GHz receiver utilizing the AFHDS 2A wireless protocol. It is equipped with a Gyro Stabilization System to enhance control stability for your RC models. The receiver provides PWM, PPM, i.bus, and s.bus data interfaces for versatile connectivity.

Figure 1: Top view of the FS-BS4 receiver, illustrating the channel ports (CH1-CH4), BIND/VCC port, SENS, SERVO, and LED indicator.

Figure 2: Angled view of the FS-BS4 receiver, highlighting the single antenna and power input range (4.0-6.5V/DC).

Figure 3: Close-up view of the FS-BS4 receiver's ports and labels, including the Flysky logo and 2.4GHz AFHDS 2A protocol indicator.
Setup
Compatibility
The FS-BS4 receiver is exclusively compatible with the Flysky FS-GT5 remote control.
Binding Process
- Ensure your FS-GT5 transmitter is powered off.
- Connect a bind plug to the BIND/VCC port on the FS-BS4 receiver.
- Apply power to the receiver (4.0-6.5V DC). The receiver's LED should flash rapidly, indicating it is in binding mode.
- While holding the BIND button on your FS-GT5 transmitter, power on the transmitter.
- The receiver's LED should stop flashing and remain solid, indicating successful binding.
- Release the BIND button on the transmitter, then power off both the receiver and transmitter.
- Remove the bind plug from the receiver.
- Power on the transmitter first, then the receiver. The receiver's LED should be solid, confirming a successful connection.
Connecting Components
- Connect your servos to the PWM channels (CH1-CH4) as required by your model.
- Ensure the power supply to the receiver is within the specified range of 4.0-6.5V DC.
- For advanced setups, utilize the PPM/i.bus/s.bus data interfaces as per your flight controller or other compatible devices' requirements.
Gyro Stabilization System
The integrated gyro stabilization system helps maintain model stability. Refer to your FS-GT5 transmitter manual for specific settings and adjustments related to the gyro sensitivity and modes. Typically, gyro settings can be adjusted via the transmitter's menu to suit different driving conditions and preferences.
Operating Instructions
After successful binding and connection of all components, power on your transmitter first, then the receiver. The receiver's LED should illuminate steadily, indicating a stable connection. Operate your RC model using the controls on your FS-GT5 transmitter. The FS-BS4 provides a remote control distance of 100-300 meters (ground) under optimal conditions.
The 4 PWM channels allow for control of steering, throttle, and other auxiliary functions depending on your model's configuration. The Gyro Stabilization System will actively assist in maintaining directional stability, especially beneficial in challenging terrain or high-speed maneuvers.
Maintenance
- Cleaning: Keep the receiver clean and free from dust, dirt, and moisture. Use a soft, dry cloth for cleaning. Avoid using solvents or harsh chemicals.
- Antenna Care: Ensure the antenna is not cut, bent sharply, or damaged. A damaged antenna can significantly reduce signal range and reliability. Position the antenna away from metal parts of the model for best reception.
- Storage: Store the receiver in a dry, cool environment when not in use. Avoid extreme temperatures and direct sunlight.
- Power Supply: Always ensure the power supply voltage is within the specified 4.0-6.5V range to prevent damage to the receiver.
Troubleshooting
- No Signal/No Control:
- Ensure the receiver is correctly bound to the transmitter. Repeat the binding process if necessary.
- Check all power connections to the receiver and ensure the voltage is within the specified range.
- Verify the transmitter is powered on and has sufficient battery charge.
- Check for any physical damage to the receiver or antenna.
- Short Range:
- Ensure the antenna is properly positioned and not obstructed by carbon fiber or metal parts.
- Check for sources of interference in the operating environment (e.g., Wi-Fi routers, other 2.4GHz devices).
- Verify the antenna is not damaged.
- Receiver LED Status:
- Solid LED: Indicates successful binding and stable connection.
- Rapidly Flashing LED: Indicates binding mode.
- Slowly Flashing LED or Off: Indicates no signal from the transmitter or power issue.
Specifications (FS-BS4)
| Feature | Specification |
|---|---|
| PWM Channels | 4 |
| Wireless Frequency | 2.4GHz |
| Wireless Protocol | AFHDS 2A |
| Remote Control Distance | 100-300m (ground) |
| Antenna Type | Single antenna (150mm) |
| Power Supply | 4.0-6.5V DC |
| RSSI Support | Yes |
| Data Interface | PWM/PPM/i.bus/s.bus |
| Temperature Range | -10°C to +60°C |
| Humidity Range | 20%-95% |
| Online Update | Yes |
| Dimensions | 35.4 x 29.6 x 13mm |
| Body Weight | 10g |
Warranty and Support
For warranty information and technical support, please refer to the purchase documentation or contact your retailer. Keep your proof of purchase for any warranty claims. For further assistance, you may also visit the official FEICHAO website or contact their customer service.