How to Output CRSF and SBUS on ExpressLRS PWM Receivers (Complete 2026 Guide)

ExpressLRS has completely transformed the FPV ecosystem by offering incredible flexibility, exceptional performance, and advanced features at an affordable price point. Most pilots use PWM receivers only for basic servo control, but that is just scratching the surface. Understanding how to output CRSF and SBUS on ExpressLRS PWM receivers opens up a world of possibilities for your RC projects. Modern ExpressLRS PWM receivers can output full serial protocols like CRSF and SBUS, making them compatible with flight controllers, drones, and advanced RC setups. In this comprehensive guide by Mall of Aviation, you will learn exactly how to output CRSF and SBUS on ExpressLRS PWM receivers step by step, unlocking the full potential of your ELRS receiver.

What is PWM vs Serial Output? Understanding the Basics

Before diving into how to output CRSF and SBUS on ExpressLRS PWM receivers, it is important to understand the difference between PWM and serial output protocols. Traditional PWM (Pulse Width Modulation) receivers output separate signals for each channel. This means if you need 8 channels, you need 8 separate wires connecting your receiver to your flight controller or servos. While this works for simple setups, it creates messy wiring and limits performance.

Serial protocols like CRSF and SBUS solve these problems by transmitting all channel data through a single wire (or two wires for bi-directional communication). Understanding how to output CRSF and SBUS on ExpressLRS PWM receivers allows you to enjoy these benefits:

• Cleaner wiring: One or two wires instead of multiple cables
• Faster communication: Higher refresh rates and lower latency
• More channels: Support for 16 or more channels
• Telemetry capability: Receive battery voltage, RSSI, and other data from your drone

Why Use CRSF or SBUS on PWM Receivers? Major Benefits

While PWM outputs are useful for fixed-wing aircraft without flight controllers, serial protocols provide major advantages for FPV drones and advanced RC systems. Here is why mastering how to output CRSF and SBUS on ExpressLRS PWM receivers is worth your time:

CRSF Protocol Benefits

• Bi-directional communication: CRSF allows two-way communication between your receiver and flight controller. This means you can receive telemetry data and GPS tracking like battery voltage, RSSI, and GPS coordinates on your transmitter.
• High refresh rates: CRSF supports up to 500Hz refresh rates, providing extremely responsive control.
• Native ExpressLRS support: CRSF is the native protocol for ExpressLRS, offering the best performance and lowest latency.

SBUS Protocol Benefits

• Wide compatibility: SBUS is supported by almost all flight controllers and RC systems.
• Simple implementation: Single-wire output makes wiring very straightforward.
• Proven reliability: SBUS has been used in FPV for many years and is a trusted protocol.

One of the biggest advantages of ExpressLRS is that how to output CRSF and SBUS on ExpressLRS PWM receivers allows PWM and serial outputs to run simultaneously. You can use PWM outputs for servos on a fixed-wing aircraft while simultaneously using CRSF for flight control telemetry.

Requirements for CRSF and SBUS Output on ELRS Receivers

Unlike older RC systems that required additional converters or hardware, ExpressLRS simplifies everything. To start learning how to output CRSF and SBUS on ExpressLRS PWM receivers, you need surprisingly little:

• An ExpressLRS PWM receiver: Models like Radiomaster ER3, ER4, ER5, ER6, or ER8 series
• USB cable or battery: To power the receiver during configuration
• WiFi-enabled device: Smartphone, tablet, or computer with WiFi capability
• Web browser: To access the receiver configuration interface

No converters are required. No additional hardware is needed. This is a huge upgrade compared to traditional RC systems where extra modules and complicated wiring were necessary. The simplicity of how to output CRSF and SBUS on ExpressLRS PWM receivers is one of the reasons ExpressLRS has become so popular among FPV pilots.

Setup for Receivers Without Serial Port Step by Step

Some ExpressLRS PWM receivers do not have dedicated RX and TX pins. Examples include the Radiomaster ER3, ER4, and ER5 series, as well as other compact ELRS PWM receivers. The good news is that how to output CRSF and SBUS on ExpressLRS PWM receivers works perfectly even without dedicated serial ports. Here is the complete step-by-step process:

Step 1: Power On the Receiver

Connect your ExpressLRS PWM receiver to a power source. You can use a USB cable if your receiver has USB support, or connect a battery (1S to 3S) to the power input pins. Make sure the receiver lights up and shows a solid or blinking LED indicator.

Step 2: Enable WiFi Mode

There are two ways to enable WiFi mode on your ExpressLRS receiver:

• Via LUA script: If you have your transmitter bound to the receiver, use the ExpressLRS LUA script to select “WiFi Mode” from the menu.
• Wait automatically: If the receiver is not bound or loses connection, it will automatically enter WiFi mode after approximately 60 seconds.

Step 3: Connect to the Receiver WiFi Network

Using your smartphone, tablet, or computer, scan for available WiFi networks. Look for a network named “ExpressLRS RX” or similar. Connect to this network. There is no password required for most receivers.

Step 4: Open the Web UI

Open your web browser and navigate to 10.0.0.1. This will open the ExpressLRS receiver configuration interface. Here you can adjust all settings, including how to output CRSF and SBUS on ExpressLRS PWM receivers.

Step 5: Configure Serial Output

In the Web UI, look for the pin mapping or channel configuration section. To successfully complete how to output CRSF and SBUS on ExpressLRS PWM receivers on a receiver without dedicated serial ports:

• Set Channel 2 function to Serial TX (transmit)
• Set Channel 3 function to Serial RX (receive) – this is usually auto-assigned
• Select your desired protocol: CRSF or SBUS
• Click the Save button to apply your changes

Step 6: Reboot and Test

After saving, the receiver will reboot. Once it restarts, Channels 2 and 3 will function as serial ports for your chosen protocol. All other channels will continue to operate as standard PWM outputs. You have now successfully learned how to output CRSF and SBUS on ExpressLRS PWM receivers.

Setup for Receivers With Dedicated Serial Port

Some ExpressLRS PWM receivers include dedicated RX and TX pins for serial communication. Examples include the Radiomaster ER6, ER8, and ER8G series. These receivers make how to output CRSF and SBUS on ExpressLRS PWM receivers even easier because they keep PWM and serial outputs completely separate.

Step-by-Step Process for Dedicated Port Receivers

1. Power on your receiver using USB or battery power.
2. Enable WiFi mode using the LUA script or by waiting 60 seconds.
3. Connect to the “ExpressLRS RX” WiFi network.
4. Open your browser and go to 10.0.0.1.
5. Navigate to the serial output or port configuration section.
6. Select either CRSF or SBUS as your output protocol.
7. Click Save and reboot the receiver.

Using SBUS on Serial Receivers: Important Considerations

By default, ExpressLRS receivers output CRSF protocol when configured for serial output. However, how to output CRSF and SBUS on ExpressLRS PWM receivers includes the option to switch to SBUS when needed. To change from CRSF to SBUS:

• Access the Web UI as described above
• Find the protocol selection dropdown menu
• Select SBUS instead of CRSF
• Choose between inverted or uninverted SBUS signal
• Save and reboot

Flight Controller Compatibility for SBUS

When using SBUS output, FPV flight controller compatibility depends on the board you are using:

• F4 Flight Controllers: Most F4 boards require an inverted SBUS signal. Connect to the dedicated SBUS pad if available.
• F7 Flight Controllers: F7 boards work with both inverted and uninverted SBUS signals, giving you more flexibility.
• H7 Flight Controllers: Similar to F7, H7 boards handle both signal types without issues.

Advanced Use Cases for CRSF and SBUS Output

Once you master how to output CRSF and SBUS on ExpressLRS PWM receivers, a world of advanced applications opens up. Here are some powerful use cases:

Hybrid Fixed-Wing FPV Builds

Imagine a fixed-wing FPV aircraft where you want servo control for ailerons, elevator, and rudder, but also want flight controller stabilization and telemetry. With how to output CRSF and SBUS on ExpressLRS PWM receivers, you can connect servos to the PWM outputs while simultaneously sending CRSF or SBUS to a flight controller. This gives you the best of both worlds.

Telemetry-Enabled Robotics

Robotics projects benefit greatly from serial communication. Learning how to output CRSF and SBUS on ExpressLRS PWM receivers allows you to send joystick data to a robotic arm or rover while receiving telemetry data back to your transmitter. This bi-directional capability is unique to CRSF and makes ExpressLRS perfect for advanced robotics.

Multi-Rotor Drones with Gimbal Control

For FPV drones with camera gimbals, you need multiple channels. How to output CRSF and SBUS on ExpressLRS PWM receivers allows you to use CRSF for flight control (4 channels) while using additional channels via PWM or SBUS for gimbal pan, tilt, and roll control.

Transitioning from PWM to Serial

If you are moving from a traditional PWM setup to a modern flight controller-based system, learning how to output CRSF and SBUS on ExpressLRS PWM receivers allows you to reuse your existing PWM receiver without buying new hardware. This saves money and reduces electronic waste.

This flexibility makes ExpressLRS one of the most future-proof RC systems available today.

Expert Tips for Best Results When Outputting CRSF and SBUS

After helping hundreds of pilots master how to output CRSF and SBUS on ExpressLRS PWM receivers, here are the most important expert tips for success:

• Use CRSF for FPV drones: CRSF offers the best performance, lowest latency, and telemetry support. For most FPV applications, CRSF is the superior choice.
• Use SBUS for compatibility: If you are using older flight controllers or equipment that only supports SBUS, that protocol works perfectly.
• Keep wiring clean and short: Serial signals can be affected by electrical noise. Keep your CRSF or SBUS wires as short as possible and away from power wires.
• Verify channel mapping: Different transmitters use different channel orders (TAER, AETR, etc.). Make sure your receiver channel mapping matches your transmitter configuration.
• Test with a signal tool: If available, use an oscilloscope or logic analyzer to verify that your serial output is working correctly.
• Update firmware first: Before configuring how to output CRSF and SBUS on ExpressLRS PWM receivers, ensure both your transmitter and receiver are on the latest firmware version.

Frequently Asked Questions About CRSF and SBUS on ELRS PWM Receivers

Final Thoughts: Master Your ExpressLRS PWM Receiver Setup

ExpressLRS PWM receivers are far more powerful than traditional RC receivers. By learning how to output CRSF and SBUS on ExpressLRS PWM receivers, you unlock capabilities that were previously only available on expensive, dedicated serial receivers.

With just a few configuration steps through the Web UI, you can:

• Convert PWM receivers to output CRSF or SBUS serial protocols
• Reduce wiring complexity significantly
• Enable telemetry and bi-directional communication
• Use the same receiver for both servo control and flight controller communication
• Save money by using PWM receivers in advanced builds

This level of flexibility makes ExpressLRS one of the most advanced and user-friendly RC systems in FPV today. Whether you are building a fixed-wing FPV aircraft, a multi-rotor drone, or a robotics project, mastering how to output CRSF and SBUS on ExpressLRS PWM receivers will serve you well.

Mall of Aviation is committed to helping you stay ahead with professional guides, tools, and FPV gear. If you found this guide helpful, check out our other tutorials on ExpressLRS configuration, flight controller setup, and advanced FPV techniques.