Channel mapping is basic but confusing for FPV drone beginners. If you get it wrong, the channel outputs in Betaflight will respond to the wrong sticks. Here is how to fix Channel Map configuration, and how to set it up properly.
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What’s Channel Map?
Channel Map is basically the order of the four control channels – Pitch, Roll, Throttle, and Yaw.
These are called differently in OpenTX:
- Roll = Aileron (AIL)
- Pitch = Elevator (ELE)
- Throttle = Throttle (THR)
- Yaw = Rudder (RUD)
That’s why channel maps are called AETR (aka AETR1234), or TAER (aka TAER1234). These are the two common channel map used in FPV drones.
You can arrange channel map in the radio’s Mixes page if you have an OpenTX radio.
Here I put Aileron on Channel 1, Elevator on Channel 2, Throttle on Channel 3 and Yaw on Channel 4, and we have channel map AETR, or AETR1234. This is the default channel map in Betaflight.
Why is Channel Map Important?
You can arrange the order of channel outputs (stick commands) with a channel map. But when the channel outputs arrive at the receiver, it’s just a series of numbers, your flight controller won’t know which number is throttle, and which number is roll. That’s why you have to tell Betaflight explicitly what channel map your are using (what order the channels are in).
If you set the wrong channel map in Betalfight, channel output will respond to the wrong stick. Your quad probably won’t arm because throttle is not at its lowest value, but if you somehow manage to arm it, it will most likely go crazy :D
How to Fix Wrong Channel Map?
Simple, just go to the Receiver tab in Betaflight Configurator, and select a different option in Channel Map:
- Betaflight’s Default channel map is AETR (or aka AETR1234)
- The other common channel map TAER (TAER1234) is under the option “Spektrum / Graupner / JR“
If none of the channel map in Betaflight works, you might have to check in your transmitter’s channel mixing and see if there is something wrong with the configuration. See instruction in the next section.
How to Change Channel Map in OpenTX?
You can decide which channel map to use in your radio transmitter, here is how you change channel map in OpenTX.
Go to the MIXES page in Model Setup. The first four channels is the channel map, which is TAER.
If I want to change it to AETR, I just need to move the channels around. Select the channel you want to move, and hold down the Enter Button. Click on the Move Option.
Move THR to CH3 (just above ELE).
Then move AIL to CH1, and move ELE to CH2. That’s it :) Now you should confirm if channel map is set correctly in Betaflight.
It doesn’t matter what order the Controls are in Inputs in OpenTX, just leave them. Channel map is determined only by Mixes.
Finally, you should be consistent with your channel map, changing it brings no benefits (AFAIK).
I recommend using AETR1234, because that’s the default in Betaflight. If you use TAER you’d have to change in Betaflight every time you setup a new quad (or flash new firmware), which is pretty pointless.