Matek Systems CRSF PWM 6-0.5 Crossfire to PWM Converter User Manual

1. Product Overview

The Matek Systems CRSF PWM 6-0.5 is a compact Crossfire to PWM converter designed to translate Crossfire protocol signals into standard PWM outputs. This device features two UARTs and six PWM outputs, making it compatible with various Crossfire Protocol receivers operating at 433MHz, 868MHz, 915MHz, or 2.4GHz.

Figure 1: Top view of the Matek Systems CRSF PWM 6-0.5 converter, showing the main chip, pins, and various pads for connections.

2. Key Features

• Compatible exclusively with Crossfire Receivers.
• No built-in 5V regulator.
• Integrated current sensor.
• Automatic failsafe value setting.
• Firmware upgradeable.
• Six (6) PWM outputs.
• Two (2) UARTs (UART1 and UART2).

3. Setup and Wiring

Careful attention to wiring is essential for proper operation. Ensure all connections are secure and correctly oriented.

3.1 Pinouts and Pads

• 4V5 Pad: The voltage on this pad is approximately 0.3V lower than the 5V pad. Ensure the voltage on the 5V pad does not exceed the rated voltage of your receiver and GPS module.
• Tx2/Rx2 (UART2): Used for GPS connection, firmware updates, and setting parameters.
• Tx1/Rx1 (UART1): Dedicated for Crossfire protocol receiver connection.
• Vbat: Battery voltage sensing input (supports 0-36V).
• Curr: Current sensor signal input (supports 0-3.3V).
• 1~6: PWM outputs for channels 1 through 6.
• G: Ground connection.

Figure 2: Top view of the converter highlighting pin labels and component layout.

Figure 3: Bottom view of the converter, showing solder pads for direct wiring.

4. Operating Instructions

4.1 Failsafe Configuration

The failsafe values are automatically set upon the first successful reception of a CRSF signal after the board is powered on. The LED will blink 8 times quickly to indicate that failsafe values have been saved.

• For channels other than CH3 (throttle), the failsafe value is the PWM value present when the CRSF signal is first received.
• For CH3 (throttle), the failsafe value is set to 988 by default.

To set failsafe: Before powering on the receiver, ensure the throttle joystick is at its lowest position, and the Aileron (Roll), Elevator (Pitch), and Rudder (Yaw) joysticks are centered.

4.2 LED Status Indicators

The onboard LED provides visual feedback on the converter's status:

• Slow Blinks: Indicates that the CRSF-PWM board is not receiving a CRSF signal. This can occur if the receiver is not bound to the transmitter, or if the receiver is not correctly connected to UART1 of the CRSF-PWM board.
• 8x Quick Blinks: Confirms that the CRSF-PWM board has successfully received a CRSF signal and the failsafe values have been saved.
• 2x Slow Blinks (between 8x fast blink and solid on): Indicates that CLI (Command Line Interface) mode is active.

5. Firmware

The Matek Systems CRSF PWM 6-0.5 converter supports firmware upgrades via UART2 (Tx2/Rx2) to ensure compatibility with future Crossfire protocol updates and to access new features or bug fixes. Refer to the official Matek Systems website for the latest firmware and upgrade instructions.

6. Maintenance

The CRSF PWM 6-0.5 converter is a robust electronic component designed for durability. No routine maintenance is typically required. Keep the board clean and free from dust, moisture, and extreme temperatures. Avoid physical stress on the pins and solder joints.

7. Troubleshooting

• No CRSF Signal (Slow LED Blinks):
  • Verify that your Crossfire receiver is properly bound to your transmitter.
  • Check all wiring connections between the receiver and UART1 (Tx1/Rx1) on the CRSF-PWM board for continuity and correct polarity.
  • Ensure the receiver is powered correctly.
• Unexpected Failsafe Behavior:
  • Re-power the CRSF-PWM board after setting your desired joystick positions (throttle low, AIL/ELE/RUD center) to re-save failsafe values. Observe for 8 quick LED blinks.
• No PWM Output:
  • Confirm that the CRSF-PWM board is receiving a CRSF signal (LED shows 8 quick blinks or solid on).
  • Check connections from PWM outputs to your servos/ESCs.

8. Specifications

9. Support

For further assistance, technical support, or the latest firmware updates, please visit the official Matek Systems website. Always refer to the manufacturer's resources for the most accurate and up-to-date information regarding your product.