This article explains the basics of the EdgeTX radio’s Input, Mix, and Output pages and what they are for. For someone new to EdgeTX, these screens of model settings may seem complicated and overwhelming at first. However, as your setup becomes more advanced, you will appreciate the flexibility and power of having these separate stages for processing input and output, especially when flying complex airplanes without FC. Let’s break it down step by step to see how they fit together and what role they play in various settings.
EdgeTX is a widely used open source radio system. Currently, all the radios I recommend use EdgeTX. Check it out here: https://oscarliang.com/radio-transmitter/#Radio-Recommendations
Why use 3 screens?
If you’re just flying a quadcopter, there’s little need to deal with input and output screens. The mix screen is all you need to map controls to channels.
The three separate steps are a continuation of the early days when radio receivers were connected directly to the ESC and servos without a flight controller. This is a common occurrence in RC models such as gliders, wings, and airplanes. Without FC, all programming would have to be done on the radio itself, so having these separate stages in OpenTX/EdgeTX gives you more control over input and output manipulation.
Now, with a flight controller, you can handle the most complex functions (speed, expo, mixing, etc.) right there. In EdgeTX, all you typically need to do is map controls to channels on the mix screen. However, the Input and Output pages are still useful if you need more advanced settings and adjustments, or if you don’t use a flight controller on your airplane.
A brief summary of the functions of each screen is as follows.
- input: If the input will be used across multiple channels in your mix, apply settings such as expo or rate once.
- Mix: This is where complex programming takes place. You can map one input to a channel, or mix different inputs into a single channel, and even configure behavior for specific channels.
- output of power: Fine-tune how signals are sent to servos or flight controllers. For example, you can invert channel outputs or adjust midpoints and endpoints if necessary.
Let’s take a closer look at each screen.
Enter: Where Control Begins
The input screen is your first stop for raw data from physical controls such as sticks, switches, knobs, and sliders. Fine tune control inputs before sending them to the mix screen. You can tweak how your input behaves by giving it a name, adjusting its weight, applying an Expo curve, setting its speed, and adjusting its offset.
The main advantage of input screens is that you can apply changes in one place and distribute the modified input to multiple channels. This simplifies the setup process by eliminating the need to repeatedly set the same adjustments for each individual channel in the mix.
For example, if you’re flying an airplane with multiple ESCs (no FC) and need to send the same throttle signal to all of them, adjust the throttle input in one place and route it to all necessary channels in the mix screen.
A common use case is to apply Expo to alleviate mid-stick sensitivity. If set here, all other functions referencing the aileron input will use the modified value. Without this screen, you would have to set up each channel on the mixer individually, which could be time consuming.
Multirotor pilots may not use this screen often, but fixed-wing and glider pilots use it to adjust airspeed and expo. For quadcopters, the default input settings usually work well.
Mix: Map inputs to channels
The mix screen is where physical inputs (such as a throttle or arm switch) are mapped to specific channels.
For example, for a fixed-wing aircraft with elevators (combined elevator and aileron inputs), the mix screen allows you to send both pitch and roll inputs to the same channel. You can also configure channel-specific settings, such as limiting servo travel or adding delay for smooth transitions (useful for flaps or landing gear). Here’s an example of setting up a mix screen for flying wings without FC (adjust expo in input screen): https://oscarliang.com/taranis-mixer-for-wings/
For FPV drones like quadcopters, setup is simpler. Mapping inputs to channels eliminates the need for mixing. A full tutorial on setting up a mix for FPV drones is here: https://oscarliang.com/taranis-mixer-for-wings/
When the radio transmits channels to the drone, the flight controller has no idea what each channel is for and all it sees is a bunch of numbers. You need to tell the flight controller what the channel is. That is, it needs to tell you which channel is the throttle, which channel is the arm switch, etc. You can do this in Betaflight’s Receiver tab and select channel maps for the first four channels (e.g. AETR1234, which maps ailerons to channel 1 and elevators to channel 2). The remaining channels typically used by the switch can then be defined in the Mode tab. For more information on setting up a channel map, check out this post: https://oscarliang.com/channel-map/
Output: Final output for the model
that output of power This is where the mix is converted into a final signal that is sent to the flight controller, ESC, or servos. The Output screen allows you to make small modifications such as setting subtrims, adjusting the min/max values of a channel (adjusting endpoints), reversing control direction, or ensuring that servos or ESCs do not go out of physical range. Both multi-rotor and fixed-wing pilots will find this screen useful.
Both multi-rotor and fixed-wing pilots will find this screen particularly useful for fine-tuning their models. For more information about adjusting the midpoint and endpoint on the output screen, check out our detailed guide here: https://oscarliang.com/adjust-tx-channel-mid-end-point/.
conclusion
Once you understand your purpose Inputs, Mixes and Outputs At EdgeTX, the true power of the system becomes evident. For simple models like multirotors, some of these screens may seem redundant, but for more complex setups, like airplanes without flight controllers or ground vehicles with complex steering mechanisms, having this level of control is invaluable.
The three-step setup may seem overwhelming at first, but as you progress, you’ll discover that this system offers unparalleled flexibility and accuracy. If you want to fine-tune your quadcopter settings or manage complex control surfaces. fixed wing Aircraft, EdgeTX’s input, mixer, and output screens give you the tools you need to succeed.
