Introduction
The world of remote control (RC) protocols can be quite overwhelming for newcomers and even experienced pilots. With advancements in technology and the constant evolution of standards, it can be challenging to keep up with all the information out there. In this article, we will simplify the various RC protocols and discuss their functionalities. Please note that this information is current as of June 2023, and protocols may have changed by the time you read this article.
RC protocols are essential for controlling various models, such as drones and fixed-wing aircraft. In this article, we will explore some of the commonly used protocols, including PWM, PPM, SBUS, CRSF, MAVLINK, and SmartPort. These protocols facilitate communication between the receiver and other components of the model, providing a seamless and efficient flying experience.
RC (remote control) protocols are essential in the field of radio-controlled devices, allowing for smooth and efficient communication between the transmitter and the receiver. In this article, we will explore some of the commonly used RC protocols, including PWM, PPM, SBUS, CRSF, MAVLINK, SmartPort, and others. By understanding these protocols, you can gain a better understanding of how RC systems function and make informed decisions when selecting and configuring your RC equipment.
Servo Speed Controllers
Servos are integral components of RC systems, responsible for controlling the movement of various parts in aircraft models. Speed controllers, on the other hand, manage the speed and power delivered to the motor or propulsion system. The protocols used for these components determine how they communicate with the flight controller or other devices.
PWM (Pulse Width Modulation)
PWM is the traditional and widely used RC protocol. It utilizes varying pulse widths to control servos and speed controllers. By adjusting the width of the pulses, the position or speed of the related component can be controlled. PWM is simple, reliable, and compatible with most RC systems. However, it only supports one channel per wire, making it less efficient for complex setups.
PPM (Pulse Position Modulation)
PPM is an older protocol that transmits multiple channel signals over a single wire. It works by encoding channel data into the position of consecutive pulses within a timeframe. PPM reduces the number of wires required for connecting receivers to flight controllers, making it a popular choice in simpler RC systems. However, it is not as efficient as newer protocols.
SBUS (Serial BUS)
SBUS is a serial communication protocol that transmits multiple channels’ data over a single wire. It is widely used in high-performance RC systems. SBUS enables faster communication between the receiver and the flight controller, supporting up to 16 channels on a single wire. This protocol is more efficient, allowing for faster response times and better control precision.
CRSF (Crossfire Shot RC Protocol)
CRSF is a proprietary RC protocol developed by TBS (Team BlackSheep) for their Crossfire long-range system. This protocol offers exceptional range and low latency, making it suitable for long-distance flights. In addition to RC control, CRSF also supports telemetry transmission, providing valuable data about the aircraft’s status.
MAVLINK
MAVLINK is a communication protocol primarily used in the field of unmanned vehicles, including drones. It allows for the exchange of messages and commands between the ground control station and the vehicle. MAVLINK is highly versatile, supporting telemetry, waypoint navigation, and other advanced features. Its compatibility with different systems makes it a popular choice in autonomous applications.
SmartPort
SmartPort is a data communication protocol developed by FrSky for their radio systems. It enables bi-directional transmission of telemetry data, providing real-time information about the aircraft’s performance and parameters. SmartPort is commonly used for monitoring battery voltage, GPS data, and flight data logs.
PWM – The Granddaddy of RC Protocols
PWM, or Pulse Width Modulation, is one of the oldest and most commonly used RC protocols. It involves sending electrical signals to control the servo motors in the model. By varying the width of the pulses, the position of the control surfaces can be adjusted. PWM is a one-way communication protocol, where information is sent from the transmitter to the receiver.
PPM – A Simpler Alternative
PPM, or Pulse Position Modulation, is another widely adopted RC protocol. Unlike PWM, which uses separate signals for each channel, PPM combines all the channels into a single signal. By encoding the position of each control surface in the time intervals between pulses, PPM simplifies the wiring and reduces the number of wires required between the transmitter and receiver.
SBUS – Two-Way Communication
SBUS is a more advanced RC protocol designed for modern flight controllers and stabilizers. Unlike PWM and PPM, SBUS is a two-way communication protocol, allowing bidirectional data transfer between the receiver and the flight controller. This enables the flight controller to send telemetry data back to the transmitter, providing valuable information like speed, altitude, battery status, and current draw.
CRSF – Crossfire’s Secret Weapon
CRSF, or Crossfire RC Serial Protocol, is a proprietary protocol developed by TBS Crossfire for long-range communication. It offers robust and reliable transmission, making it ideal for applications where a strong and stable connection is crucial. CRSF also allows bidirectional communication, enabling the transmitter to receive telemetry data from the model, ensuring a high level of control and situational awareness.
MAVLINK – The Universal Language
MAVLINK is an open-source RC protocol widely used in the field of autonomous systems, particularly in the realm of drones. It is a lightweight messaging protocol that enables communication between different components of an unmanned vehicle, such as the flight controller, ground station, and onboard sensors. MAVLINK supports bidirectional communication, facilitating seamless control and real-time data exchange.
SmartPort – Integration at its Finest
SmartPort is a protocol developed by FrSky, a renowned brand in the RC community. It allows for seamless integration between FrSky receivers and their telemetry-enabled transmitters. SmartPort provides bidirectional communication, enabling the transmitter to receive real-time telemetry data from the model. This data can be displayed on the transmitter’s screen, providing vital information for the pilot.
Introduction to RC Protocols
RC protocols are an essential part of the hobby of remote control vehicles and devices. They allow for the seamless communication between the transmitter and receiver, enabling a smooth and accurate control of the vehicle or device. In this article, we will discuss some commonly used RC protocols, namely PWM, PPM, SBUS, CRSF, MAVLINK, and SmartPort.
Pulse Width Modulation (PWM)
Pulse Width Modulation, or PWM for short, is one of the most familiar RC protocols for those who have been involved in the hobby. It uses three wires to connect the receiver to the outputs. These wires are grouped into three pins, which include a ground pin, a +5V pin, and a signal pin. Servos and electronic speed controllers (ESCs) are connected to these pins.
PWM works by sending a pulse along the cable, and the duration of this pulse corresponds to the signal’s magnitude. However, accurately measuring this pulse is crucial, and both the receiver end and the servo or speed controller need to be able to do this. Calibration and setting midpoints for servos are common tasks in the PWM domain. Furthermore, PWM is not particularly fast, with most analog servos operating at a standard 50 Hz.
Pulse Position Modulation (PPM)
Pulse Position Modulation, or PPM, is another RC protocol that simplifies the wiring compared to PWM. Instead of using individual wires for each channel, PPM combines them into a single wire. This means that all the channels share the same time slot within the PPM signal.
To achieve this, PPM relies on a unique pattern of pulse positions to represent different values for each channel. The receiver reads the position of each pulse and decodes it accordingly to determine the corresponding signal value. PPM is a relatively older protocol but is still widely used due to its simplicity and compatibility with various RC systems.
Serial Bus (SBUS)
Serial Bus, or SBUS, is a digital protocol that has gained popularity in recent years. It uses a single wire to transmit data, reducing the number of wires needed compared to PWM and PPM. SBUS offers higher resolution and faster transmission speed, making it suitable for more advanced applications.
The SBUS protocol sends data as a stream of bits, with each bit representing a specific information value. The receiver decodes this stream and sends the corresponding signals to the connected devices. SBUS also allows for multiple channels to be combined into a single signal, simplifying the wiring further.
Crossfire (CRSF)
Crossfire, or CRSF, is a long-range RC protocol developed by Team BlackSheep. It is specifically designed for high-performance, low-latency, and long-range applications. CRSF offers a reliable and robust communication link, ensuring a stable connection between the transmitter and receiver.
One notable feature of CRSF is its bi-directional communication, allowing for data telemetry and firmware updates. This enables users to receive real-time information, such as battery voltage and GPS coordinates, from their vehicles or devices. Furthermore, CRSF operates in the 2.4 GHz frequency band, reducing interference and improving reliability.
MAVLINK
MAVLINK is a communication protocol commonly used in the field of unmanned aerial vehicles (UAVs) and robotics
Understanding RC Protocols
RC protocols are the backbone of communication between remote control devices and the receivers they are connected to. These protocols determine the speed and efficiency at which these devices interact with each other. In this article, we will explore some of the commonly used RC protocols and explain them in simple terms.
PWM: Pulse Width Modulation
Pulse Width Modulation, or PWM, is one of the oldest and most widely used RC protocols. With PWM, the receiver sends a series of electrical pulses to control the position of servos or the speed of motors. Each pulse’s duration represents a specific control value. For example, a 1ms pulse might mean full throttle, while a 2ms pulse could indicate neutral position.
While PWM is simple and reliable, it has its limitations. Firstly, it operates at update speeds of around 100-150 Hz, which may not be suitable for applications requiring faster response times. Additionally, PWM is a one-way communication method, meaning that data flows only from the receiver to the servos or speed controllers.
Another drawback of PWM is its pin-intensive nature. Each servo or speed controller requires three pins on the receiver for communication. Consequently, if you want multiple servos and speed controllers, you would need a receiver with numerous PWM outputs, resulting in a cluttered wiring setup.
PPM: Pulse Position Modulation
To address the limitations of PWM, Pulse Position Modulation, or PPM, was introduced. PPM simplifies wiring by sending signals one after another down a single wire. This improvement significantly reduced cable clutter and made it more manageable to connect multiple devices to the receiver.
With PPM, the receiver sends a series of pulses, and the position of each pulse represents a specific control value. By aligning these pulses in a sequential manner, PPM streamlines communication between the receiver and the connected devices.
If you have a receiver capable of outputting a PPM stream, you can plug it into the receiver, reducing the need for multiple PWM outputs and the associated wiring complexity.
SBUS: Serial Bus
SBUS, or Serial Bus, is a newer RC protocol that is commonly used in modern flight controllers. It utilizes serial communication to transmit multiple channels over a single wire. SBUS provides fast update speeds, typically around 100-200 Hz, enabling quick and precise control.
With SBUS, the receiver converts the individual servo signals into a digital data stream, which is then transmitted to the flight controller. This stream contains the information for all connected channels, reducing wiring requirements and simplifying the overall system.
CRSF: Crossfire Protocol
CRSF, or Crossfire protocol, is a proprietary RC protocol developed by TBS for long-range control. Designed specifically for remote control systems that require extended range, CRSF offers ultra-fast update speeds and low latency.
The Crossfire system utilizes a transmitter module and a receiver module to establish a robust and reliable long-range communication link. This protocol is commonly used in FPV drones and other long-range RC applications where maintaining a strong signal connection is crucial.
MAVLINK: Micro Air Vehicle Link
MAVLINK is an open-source communication protocol designed for micro air vehicles (MAVs) such as drones. It enables bidirectional communication between the MAV and ground control stations, allowing for data exchange and
PPM – An Analog Signal
The first RC protocol we will discuss is PPM or Pulse Position Modulation. When you connect the cable to your flight controller, it sends an analog signal in the form of little pulses that travel one after the other. These pulses start with channel one and continue until the end of the channel sequence. Therefore, the order of transmission is Channel 1, 2, 3, 4, 5, and so on. However, PPM still has its limitations. The accuracy of measuring the pulses and the analog nature of the signal pose challenges. Additionally, the need to wait for all the signals and values to be sent before starting again makes PPM a relatively slow protocol.
SBUS – The Digital Innovation
The next major development in RC protocols was SBUS. While some may consider it a legacy protocol, it is still widely used and supported as the open standard for digital signals in the RC community. The setup for SBUS is similar to PPM, requiring three wires for ground, 5 volts for power, and one signal cable for transmission. However, SBUS takes a significant leap forward in terms of performance and efficiency.
Switching to Digital Packets
Unlike PPM, which relies on measuring pulses to determine channel values, SBUS uses digital packets for transmission. This is similar to a computer network, where data is organized into packets and sent across a wire. By adopting this digital approach, SBUS eliminates the need for precise pulse measurements and improves overall accuracy. The use of digital packets also allows for faster transmission and reception of channel values.
The Widely Supported Standard
SBUS has become the go-to protocol for many RC enthusiasts due to its widespread support. Most RC devices and systems are compatible with SBUS, making it a reliable and versatile choice. However, it’s worth noting that as of the time of this recording, Express LRS does not support SBUS. Nevertheless, there is hope that SBUS compatibility will be added in the near future.
Other RC Protocols
While PPM and SBUS are two prominent RC protocols, there are several others worth mentioning. CRSF, or Crossfire Serial Protocol, is popular among long-range FPV pilots due to its robustness and reliability. MAVLink, on the other hand, is a protocol commonly used in drone autopilot systems, allowing for communication between ground stations and aircraft. SmartPort is a protocol specific to FrSky receivers, enabling telemetry data transmission.
In conclusion, understanding the various RC protocols is essential for any RC enthusiast. While PPM served as the initial analog signal transmission method, SBUS revolutionized the industry by introducing digital packets. With its widespread support, SBUS remains a go-to choice for many RC systems. However, other protocols such as CRSF, MAVLink, and SmartPort also play vital roles in specialized applications. So whether you are a beginner getting started with your first RC system or an experienced pilot exploring advanced features, having a grasp of these protocols will enhance your RC experience.
PWM (Pulse Width Modulation)
Traditionally, PWM has been the most widely used RC protocol. It works by varying the width of pulses to represent different values. For example, a pulse width of 1000μs may indicate a minimum value, while 2000μs may represent a maximum value.
PPM (Pulse Position Modulation)
PPM is another commonly used RC protocol that predates PWM. Unlike PWM, which sends pulses with varying widths, PPM sends a series of pulses with fixed widths but varying time gaps between them. Each gap represents a different value for a specific channel.
SBUS (Serial Bus)
SBUS is a digital RC protocol that simplifies the communication process. Instead of measuring pulse widths, SBUS sends the actual channel values as part of the signal. This allows for faster transmission of information and eliminates the need for calibration, as the discrete channel values are already included in the signal.
Advantages of SBUS
There are several advantages to using SBUS. Firstly, the transmission speed is significantly increased compared to older protocols like PPM. With PPM, if all channels have high values, the transmitter has to wait to send the long pulses. SBUS, on the other hand, sends the same amount of information regardless of channel values, resulting in quicker transmission.
Secondly, SBUS allows for the insertion of additional information along with channel values. This includes error checking to ensure the accuracy of the received information, a common practice in computer systems. Furthermore, flags or bits can be set to indicate whether the system is in fail-safe mode or other specific conditions.
CRSF (Crossfire Shot)
CRSF is a low-latency digital RC protocol developed by TBS (Team BlackSheep). It is commonly used for long-range RC systems and provides reliable and secure communication between the transmitter and receiver.
MAVLINK
MAVLINK is a protocol used primarily in the field of autonomous vehicles and drones. It enables communication between onboard systems and ground control stations, allowing for real-time data transmission during flight operations. The MAVLINK protocol is highly customizable and supports various data types and formats.
SmartPort
SmartPort is a digital protocol developed by FrSky, primarily used in their RC systems. It allows for bidirectional communication between the transmitter and receiver, enabling the transmission of telemetry data and system information in addition to RC commands.
SBUS – The Usability Champion
RC protocols come in various forms, but one that stands out in terms of usability is SBUS. Unlike PWM and PPM, SBUS offers a more streamlined and efficient way of connecting receivers to flight controllers or stabilizers. In addition to its compatibility with these devices, SBUS also allows for the connection of other components such as servos. Its versatility makes it a popular choice among RC enthusiasts.
The Pitfalls of Proprietary Protocols
While SBUS may be a reliable option, there are other protocols out there that you may come across. However, it is important to note that many of these protocols are proprietary. This means that they are developed by specific individuals or companies, often with the intention of improving upon existing standards such as PWM or PPM. The drawback here is that using proprietary protocols can lead to compatibility issues with other devices. It becomes a struggle to figure out how to work with these protocols, as they are not as widely supported as open standards.
PPM and PWM – The Old Standards
Before delving further into the world of RC protocols, it is worth mentioning the two older standards – PPM and PWM. These protocols have been around for quite some time and have served their purpose. They are still widely used, especially in older RC systems. However, compared to SBUS, they lack the efficiency and convenience that modern enthusiasts seek. PPM and PWM require more connections and tend to be less user-friendly overall.
Exploring Other RC Protocols
Aside from SBUS, there are several other RC protocols that you may encounter. These protocols might have their own unique features or advantages, but their proprietary nature often hinders widespread adoption. It is always safer to stick with open standards, as they offer better compatibility and support within the RC community.
MAVLINK and SmartPort – Specialized Choices
Among the lesser-known protocols are MAVLINK and SmartPort. These protocols tend to cater to specific needs or applications within the RC hobby. MAVLINK, for example, is commonly used in the field of autonomous drones and ground control systems. On the other hand, SmartPort is a protocol developed by FrSky, specifically for their range of RC receivers. While both MAVLINK and SmartPort have their own merits, they may not be essential for the average RC enthusiast.
In conclusion, when it comes to RC protocols, simplicity and compatibility are key. SBUS stands out as a user-friendly and versatile option for connecting receivers to flight controllers or stabilizers. While there are other protocols available, many of them are proprietary and may pose compatibility issues. It is advisable to stick with open standards to ensure a seamless RC experience.
RC Protocols Explained: PWM, PPM, SBUS, CRSF, MAVLINK, SmartPort and others
The Evolution of RC Protocols
In the world of RC (Remote Control) systems, various protocols have emerged over the years to facilitate communication between transmitters, receivers, and other components. While some of these protocols are specific to certain manufacturers, understanding them is crucial for RC enthusiasts. In this article, we will simplify the explanation of some of the most commonly encountered RC protocols.
PWM and PPM
PWM (Pulse Width Modulation) and PPM (Pulse Position Modulation) are two traditional methods used to transmit radio control signals from the receiver to servos, ESCs (Electronic Speed Controllers), flight controllers, or flight stabilizers. PWM involves varying the width of the electrical pulses to convey control signals, while PPM transmits signals by varying the position of pulses within a fixed frame.
SBUS
SBUS is a digital serial communication protocol developed by Futaba. It allows for multiple channels to be transmitted over a single wire, making it efficient and capable of transmitting high-resolution control signals. SBUS has gained popularity in the RC community due to its simplicity and compatibility with various systems.
CRSF
CRSF (Crossfire Shot Protocol) is a protocol developed by TBS (Team BlackSheep) for long-range RC systems. It provides low-latency communication, high data throughput, and reliable link quality. CRSF has become a popular choice among FPV (First Person View) drone pilots who require long-range capabilities.
MAVLINK
MAVLINK is an open-source communication protocol widely used in the field of autonomous vehicles, including drones. It enables communication between different components of a drone system, such as flight controllers and ground control stations. MAVLINK supports the exchange of telemetry data, commands, and status updates.
SmartPort
SmartPort is a protocol developed by FrSky for their RC systems. It allows for bi-directional communication between the receiver and the flight controller. SmartPort enables the transmission of telemetry data, such as battery voltage, RSSI (Received Signal Strength Indicator), and GPS information, back to the transmitter or even a PC.
Other Protocols
Apart from the aforementioned protocols, there are numerous other protocols used by specific manufacturers or systems. For example, Fly Sky utilizes the i-BUS protocol, while Spectrum uses the DSM and DSM2 protocols. These protocols were more commonly found a few years ago but are now less prevalent in the wider RC hobby community. Investing in equipment that relies on these protocols may lead to compatibility issues with newer systems.
Conclusion
Understanding the various RC protocols is essential for RC enthusiasts. From traditional methods like PWM and PPM to modern protocols like SBUS, CRSF, MAVLINK, and SmartPort, each protocol offers unique advantages and functionalities. By staying informed about these protocols, RC enthusiasts can make informed choices when selecting equipment and ensure compatibility within their RC systems.
Mavlink Protocol
Mavlink is a protocol that has been developed for use in the Pixhawk and U-pilot side of the hobby. It is a very robust system that uses two cables. Typically, it would be plugged into a UART, just like the SmartPort. This means that you would have two connections to your flight controller – one for your SBUS and one for your SmartPort.
One of the advantages of Mavlink is that it can be used for both radio control and telemetry. The fact that it has two wires, a receive and transmit pin, means that you can also send data to the flight controller over this telemetry link. This is where Mavlink becomes really powerful. You can use things like telemetry radios and have the live telemetry displayed on your computer. From the perspective of your computer, the radio link just looks like a really long USB cable.
CRSF Protocol
Crsf, not to be confused with Crossfire, is another popular protocol in the hobby. Crossfire is a radio system developed by Team Black Sheep, while Crsf is the protocol that the receiver talks to the flight controller with. Crsf also uses four wires – ground, 5 volts, transmit, and receive. These wires are plugged into a UART on your flight controller.
The Crsf protocol sends the radio control information, such as the position of all your radio controls, to the flight controller. However, it also receives all the telemetry back and sends it down to the radio. This is a fast, robust, and brilliant system developed by TBS and used in their Crossfire system.
Other RC Protocols
In addition to Mavlink and Crsf, there are several other RC protocols commonly used in the hobby. Some of these include PWM, PPM, SBUS, and SmartPort.
PWM (Pulse Width Modulation) is one of the oldest and simplest protocols used in RC systems. It works by varying the width of the pulses sent to the receiver, which in turn controls the position of the servos.
PPM (Pulse Position Modulation) is similar to PWM but uses a single wire to send all the channels of information as a series of pulses. This allows for multiple channels of information to be transmitted through a single wire.
SBUS is a digital protocol that allows for multiple channels of information to be transmitted through a single wire. It is commonly used in modern RC systems due to its high resolution and low latency.
SmartPort is a protocol developed by FrSky that allows for bidirectional communication between the receiver and the flight controller. It can transmit telemetry data, such as battery voltage and GPS information, to the receiver, which can then be displayed on a telemetry-enabled RC transmitter.
These are just a few examples of the many RC protocols available in the hobby. Each protocol has its own strengths and weaknesses, and the choice of which one to use depends on the specific requirements of the RC system.
PWM, PPM, and SBUS Explained
In the world of RC (radio control), there are various protocols that govern the communication between the transmitter and the receiver. Three commonly used protocols are PWM, PPM (Pulse Position Modulation), and SBUS.
PWM, or Pulse Width Modulation, is the oldest and most basic protocol. It works by varying the width of pulses to control the position of servo motors. Each pulse represents a specific command, such as throttle or steering.
PPM, on the other hand, is a digital protocol that sends multiple channels of information by encoding them into a single signal. This results in a reduction in wiring complexity, making it popular in compact RC systems.
SBUS, short for Serial Bus, is a digital protocol developed by Futaba. It allows for more channels of information to be transmitted over a single wire, providing improved performance and reducing clutter.
Introduction to CRSF
CRSF, or Crossfire Radio System Protocol, is a digital control protocol developed by TBS (Team BlackSheep). It is known for its reliability and low latency, making it a popular choice among RC enthusiasts.
The CRSF protocol uses four connections: power, ground, transmit, and receive. This enables full two-way communication between the transmitter and receiver, allowing for enhanced functionality.
The Rise of CRSF
CRSF has gained significant popularity and is expected to become a standard in the RC hobby. Its robustness and ease of use make it an attractive option for both beginners and experienced pilots.
It is worth mentioning the cooperation between TBS and Express LRS. Express LRS is an open standard protocol that is not owned by any specific vendor. Its adoption of the CRSF protocol has further solidified its position as a go-to standard in the hobby.
Setting up CRSF
To set up a CRSF system, most flight controllers offer specific UARTs and ports where you can connect the CRSF receiver. By connecting the four wires (power, ground, transmit, and receive) and configuring the flight controller for CRSF telemetry, you can enjoy a robust and reliable RC system.
For those who prefer Express LRS or TBS Crossfire, the process is similar. By connecting the four wires and enabling telemetry, you can create a powerful and efficient RC setup.
Choosing the Right Protocol
If you’re wondering which protocol to choose for your RC system, the answer is becoming increasingly clear. The CRSF protocol, with its wide adoption and compatibility, offers a reliable and future-proof solution.
Whether you’re a beginner entering the hobby or an experienced pilot looking to upgrade your system, consider CRSF as the default option. Its versatility and features make it a top choice among RC enthusiasts.
In conclusion, understanding the various RC protocols available is essential for building a reliable and efficient RC system. From traditional protocols like PWM and PPM to advanced ones like CRSF, the choice ultimately depends on your needs and preferences. However, with the rising popularity of CRSF, it is definitely worth considering as the go-to protocol for your RC adventures.
CRSF Protocol
If you have the option, it is highly recommended to use the CRSF (Crossfire) protocol, especially with systems like Express LRS, TBS Crossfire, or the Tracer system. This protocol allows you to get telemetry data back to your radio and ensures fast and reliable transmission of radio control signals from the receiver to the flight controller.
One of the standout features of the CRSF protocol is its dynamically built menu system, which offers a wide range of cool features. Although I won’t delve into the details of these features now, they greatly enhance the usability and functionality of the system. This protocol is future-proof and has been chosen by the Express LRS team as the preferred protocol for their receivers.
SBUS Protocol
SBUS is another widely supported and open standard protocol that still finds extensive usage today. It is quite rare to come across a piece of equipment that does not support SBUS. Even though the Express LRS team has considered SBUS as a legacy protocol for some time, its compatibility and prevalence cannot be overlooked.
In particular, SBUS’s one-wire connection makes it an attractive option, especially for devices such as flight stabilizers for airplanes. Many such devices only understand SBUS and PPM, making SBUS an essential choice in certain cases. It’s baffling that the Express LRS project took so long to include support for SBUS, considering the abundance of equipment that relies on it.
SmartPort and Other Protocols
If you have a spare receiver that supports SBUS and perhaps even has a SmartPort connection for telemetry, it is advisable to make use of it. SmartPort is a protocol used for bidirectional communication between a receiver and a telemetry-enabled device. It allows for the exchange of data like battery voltage, current consumption, and GPS information.
Apart from CRSF, SBUS, and SmartPort, there are numerous other protocols that are commonly used in the RC hobby. These include PWM (Pulse Width Modulation) and PPM (Pulse Position Modulation), which are older but still prevalent protocols. They have limitations compared to newer protocols but are widely compatible with various devices.
Another protocol worth mentioning is MAVLink. MAVLink is a protocol designed for communication between unmanned vehicles and ground control stations. It provides a common language for exchanging flight control, telemetry, and mission-related information.
In conclusion, when it comes to RC protocols, it is recommended to leverage the CRSF and SBUS protocols due to their widespread compatibility, reliability, and the availability of advanced features. However, the choice of protocol depends on the specific requirements of your project and the compatibility of your equipment.
Understanding RC Protocols
RC protocols are an essential aspect of the radio control hobby, allowing enthusiasts to transmit commands and receive data between their remote control devices, such as transmitters and receivers. In this article, we will explore some commonly used RC protocols including PWM, PPM, SBUS, CRSF, MAVLINK, and SmartPort, and how they simplify communication in the world of RC.
PWM
PWM, or Pulse Width Modulation, is one of the oldest and most widely used protocols in the RC community. It works by varying the width of the pulse to control the position of servos and the speed of motors. By adjusting the pulse width, the signal can be interpreted by the receiver to determine the desired action.
PPM
PPM, or Pulse Position Modulation, is another popular RC protocol. Unlike PWM, PPM combines multiple channels into a single signal. This is achieved by sequentially encoding each channel’s information into varying pulse positions within a single pulse train. PPM is widely supported by many RC systems and offers a more efficient use of communication bandwidth.
SBUS
SBUS, or Serial Bus, is a digital protocol developed by Futaba. It allows for simultaneous transmission of multiple channels over a single wire, reducing wiring complexity and minimizing latency. SBUS offers high-resolution, low-latency control, making it popular among drone pilots and FPV racers.
CRSF
CRSF, or Crossfire, is a protocol developed by TBS for long-range RC systems. It utilizes a bidirectional communication link, enabling telemetry data to be transmitted back to the transmitter, providing valuable information like battery voltage, GPS coordinates, and RSSI. CRSF simplifies the wiring setup by using a single UART connection for both control and telemetry data.
MAVLINK
MAVLINK, or Micro Air Vehicle Link, is a protocol commonly used in the field of unmanned aerial vehicles (UAVs) and drones. It facilitates communication between the flight controller and the ground control station, allowing for real-time data transmission, such as GPS coordinates, altitude, and sensor telemetry. MAVLINK supports both command and control functions, making it a comprehensive protocol for UAV operations.
SmartPort
SmartPort is a protocol developed by FrSky, a well-known name in the RC community. It combines both control and telemetry data, allowing for bidirectional communication between the transmitter and receiver. With SmartPort, users can access valuable information like battery voltage, current draw, and flight mode status directly from their transmitters.
Conclusion
As the world of RC protocols continues to evolve, it’s essential to stay updated on the latest developments. Understanding the functionalities and purposes of different protocols can help you navigate the vast amount of information available. Whether you are a beginner or an experienced pilot, choosing
In conclusion, RC protocols play a crucial role in enabling smooth and efficient communication between the transmitter and receiver. PWM, PPM, SBUS, CRSF, MAVLINK, and SmartPort are just a few of the many protocols available, each with its own advantages and use cases. The development of bidirectional communication has revolutionized the RC hobby, allowing for advanced features like telemetry data display and enhanced control. As technology advances, we
Understanding RC protocols is crucial for anyone involved in the world of radio-controlled devices. Whether you’re a hobbyist or a professional, having a grasp of different protocols like PWM, PPM, SBUS, CRSF, MAVLINK, SmartPort, and others can enhance your RC experience and help you optimize your equipment for better performance and reliability.
Understanding RC protocols is crucial for RC hobbyists and professionals alike. Whether you are controlling a drone, a car, or a plane, selecting the appropriate protocol ensures efficient and reliable communication between your transmitter and receiver. From the traditional PWM and PPM to the more advanced SBUS, CRSF, MAVLINK, and SmartPort, each protocol brings its own benefits and simplifies the way we control our RC devices. By staying up-to-date with the latest protocols, you can make the most of your RC experience and enjoy the exciting world of radio control.
