JHEMCU RP4-TD ELRS 2.4GHz True Diversity Receiver

Introduction

The JHEMCU RP4-TD is an advanced ELRS 2.4GHz True Diversity Receiver designed for long-range FPV racing drones. It features an ESP32 PICO D4 microcontroller and dual SX1280 radio frequency chips, providing robust and reliable signal reception. This manual provides essential information for proper installation, configuration, and operation of your RP4-TD receiver.

Specifications

Package Contents

• RP4-TD 2.4G Diversity Receiver x1
• 2.4G T-type antenna x2
• Heat Shrink Tube x1
• Wire x4

Product Overview

The RP4-TD receiver features two IPEX MHF 1/U.FL antenna connectors for true diversity operation, ensuring optimal signal reception. Key components include the ESP32 PICO D4 MCU and dual SX1280 chips. The board provides clearly labeled pads for power (5V, GND) and serial communication (RX, TX).

Setup

1. Wiring

Refer to Figure 3 for the pinout diagram. Connect the receiver to your flight controller as follows:

• 5V: Connect to a +5V power source on your flight controller.
• GND: Connect to a Ground pad on your flight controller.
• TX: Connect to an RX pad (e.g., RX2) on your flight controller.
• RX: Connect to a TX pad (e.g., TX2) on your flight controller.

Ensure proper polarity to avoid damage to the receiver or flight controller.

2. Antenna Installation

Carefully connect the two provided 2.4G T-type antennas to the IPEX MHF 1/U.FL connectors on the receiver board. Ensure they are securely attached. Position the antennas on your drone to maximize signal separation and minimize interference, typically at a 90-degree angle to each other.

3. Firmware Flashing (if necessary)

The receiver comes pre-flashed with ELRS V3.2 firmware. If you need to update or change the firmware, follow the standard ExpressLRS flashing procedure using the ExpressLRS Configurator. Connect the receiver to your computer via a USB-to-UART adapter (not included) or use passthrough flashing through your flight controller. Select the correct target for ESP32 PICO D4 and SX1280.

4. Binding Procedure

To bind the RP4-TD receiver to your ELRS transmitter module:

1. Power on your flight controller (with the receiver connected) and then immediately power it off. Repeat this process three times.
2. On the fourth power-up, the receiver's LED should flash rapidly, indicating it is in binding mode.
3. Ensure your ELRS transmitter module is also in binding mode (typically by selecting 'Bind' in the Lua script or powering it on without a receiver connected).
4. The receiver LED will turn solid when successfully bound.

Alternatively, if your transmitter and receiver share the same binding phrase, they will bind automatically upon power-up.

Operating Instructions

Once the receiver is successfully bound and configured in your flight controller's software (e.g., Betaflight, ArduPilot), it will provide control signals to your drone. The true diversity feature automatically selects the best signal from the two antennas, enhancing link reliability and range. Monitor your RSSI (Received Signal Strength Indicator) and LQ (Link Quality) values on your OSD (On-Screen Display) or transmitter to ensure a healthy radio link during flight.

Maintenance

• Keep the receiver clean and free from dust and debris.
• Inspect antenna connections regularly for damage or loose fittings.
• Ensure the heat shrink tube is properly applied to protect the board from short circuits and environmental factors.
• Avoid exposing the receiver to extreme temperatures or moisture.
• Periodically check for firmware updates for improved performance and features.

Troubleshooting

• No Link/Binding Failure: Double-check wiring, ensure both transmitter and receiver are on the same ELRS firmware version and binding phrase (if used). Verify the binding procedure is followed correctly.
• Intermittent Signal: Check antenna placement and orientation. Ensure antennas are not obstructed by carbon fiber or other conductive materials. Verify antenna connectors are secure.
• Receiver Not Powering On: Confirm 5V and GND connections are correct and receiving power from the flight controller.
• Incorrect Control Inputs: Verify UART settings in your flight controller software (e.g., Betaflight Ports tab) and ensure the correct receiver protocol (CRSF) is selected.

User Tips

• For optimal range and signal quality, ensure your antennas are mounted away from other electronics and carbon fiber parts of your drone.
• Consider using a small piece of double-sided foam tape to secure the receiver to your drone, reducing vibration.
• Always perform a range check before flying, especially after making changes to your setup.

Compliance and Safety Information

This device complies with relevant technical standards for radio equipment. Users are responsible for operating this device in accordance with local regulations and laws regarding radio control equipment. Always ensure safe operation of your FPV drone and maintain a safe distance from people and property.

Warning: This product is not a toy. It is intended for use by individuals aged 14 years and older with experience in operating remote-controlled vehicles.

Support

For further assistance, technical support, or inquiries regarding the JHEMCU RP4-TD receiver, please refer to the official JHEMCU website or contact your retailer.