# How to Set Up Betaflight AUX Switches and Mode Ranges
Your radio’s switches control everything beyond basic flight — arming, flight modes, buzzer, turtle mode, and more — but only if they’re correctly configured in Betaflight. Misconfigured AUX ranges cause failed arming, unexpected mode changes, and crashes. This guide walks through the complete Modes tab setup.
## Understanding AUX Channels
Your radio sends 4+ channels to the flight controller. The first four are typically reserved for flight controls:
| Channel | Default Function | Range |
|———|—————–|——-|
| CH1 | Roll (Aileron) | 1000-2000 |
| CH2 | Pitch (Elevator) | 1000-2000 |
| CH3 | Throttle | 1000-2000 |
| CH4 | Yaw (Rudder) | 1000-2000 |
| CH5 (AUX1) | Arm switch | 1000-2000 |
| CH6 (AUX2) | Flight mode switch | 1000-2000 |
| CH7 (AUX3) | Buzzer / Turtle mode | 1000-2000 |
| CH8 (AUX4) | Additional functions | 1000-2000 |
## Step 1: Map Switches to Channels on Your Radio
Before touching Betaflight, assign physical switches to channels on your radio:
### EdgeTX / OpenTX Setup
1. Press **MDL** → **MIXER**
2. Scroll to CH5 → Edit → Source = **Switch A** (SA) or your preferred switch
3. For 3-position switches, the switch naturally outputs 1000 (up), 1500 (middle), 2000 (down)
4. Repeat for CH6, CH7, CH8 with additional switches
### ExpressLRS Configuration
If using ELRS, 2-position and 3-position switch positions are part of the CRSF protocol by default. Just assign them in the radio’s mixer.
## Step 2: Verify in Betaflight Receiver Tab
1. Open Betaflight Configurator → **Receiver tab**
2. Power on your radio
3. Flip each switch and watch the AUX channel bars:
| Switch Position | Channel Value | Meaning |
|—————-|—————|———|
| Up | ~2000 | High |
| Middle | ~1500 | Center |
| Down | ~1000 | Low |
If your switch positions don’t hit these values, adjust the **Channel Endpoints** on your radio (OUTPUTS page in EdgeTX).
## Step 3: Configure Modes Tab
Go to the **Modes tab** in Betaflight. Each mode requires an AUX channel and an activation range.
### ARM Mode (Critical)
| Setting | Value | Why |
|———|——-|—–|
| Channel | AUX1 | Dedicated arm switch |
| Range | One switch position (e.g., 1900-2100) | Avoid accidentally arming when switch is bumped |
**⚠️ Always use a dedicated 2-position switch for arm.** Never put arm on a 3-position switch or combine it with other modes. A momentary switch (spring-loaded) for an “arm on hold” setup works but is harder for beginners.
### Flight Modes: Angle / Horizon / Acro
Use a single 3-position switch for flight modes:
| Switch Position | Mode | Range |
|—————-|——|——-|
| Up (2000) | Angle | 1800-2100 |
| Middle (1500) | Horizon | 1300-1700 |
| Down (1000) | Acro (no mode selected) | Default — no mode active |
**Pro tip**: If you only want Angle and Acro, use a 2-position switch and map Angle to one position. The other position with no active mode defaults to Acro.
### Buzzer
| Setting | Value |
|———|——-|
| Channel | AUX3 or AUX4 |
| Range | One switch position |
Enable the **RX_SET** override so the beeper works even if your radio link drops — critical for finding lost quads.
### Turtle Mode (Flip Over After Crash)
| Setting | Value |
|———|——-|
| Channel | Same as Buzzer (AUX3) — different position |
| Range | Opposite switch position from Buzzer |
The buzzer and turtle mode share a 3-position switch beautifully:
| Switch Position | Function | Range |
|—————-|———-|——-|
| Up | Buzzer | 1800-2100 |
| Middle | Nothing (default) | 1300-1700 |
| Down | Turtle Mode | 900-1200 |
### Other Useful Modes
| Mode | Recommended Channel | Why |
|——|———————|—–|
| **Prearm** | AUX5 or separate switch | Two-switch arm sequence prevents accidental arming |
| **Blackbox Log** | AUX5 (3-pos: off/on/erase) | Only log when you need to; saves flash space |
| **VTX Pit Mode** | AUX5 or AUX6 | Power down VTX while waiting on the starting line |
| **Camera Control** | AUX5 | Switch between FPV and HD camera (if supported) |
| **GPS Rescue** | Dedicated switch | Emergency RTH activation |
## Step 4: Prearm — The Safety Net
A Prearm switch adds an extra step to arming, preventing accidental arming from a single bump:
1. Assign a momentary switch (spring-loaded button) to CH6 or CH7
2. In Modes tab, add **Prearm** mode with its range
3. Now: **Prearm held + Arm switched** → quad arms
This is especially important if you handle your quad with the battery plugged in.
## Complete Recommended Switch Layout (5-inch Freestyle)
| Switch | Type | Function |
|——–|——|———-|
| SA (2-pos) | Toggle | ARM |
| SB (3-pos) | Toggle | Flight Mode: Angle / Horizon / Acro |
| SC (3-pos) | Toggle | Buzzer / Nothing / Turtle Mode |
| SD (2-pos) | Toggle | Prearm (hold momentary if available) |
| Pot/Slider | Knob | VTX power or camera angle adjustment (optional) |
## Recommended Radio
A radio with ample switches and excellent gimbals makes mode configuration effortless. The **RadioMaster Boxer** features 4 toggle switches, 2 momentary buttons, 2 sliders, and full-size Hall-effect gimbals — more than enough for any mode setup. Available at [uavmodel.com](https://uavmodel.com).
## Video: Betaflight Modes Tab Setup
## Verify Everything Before Flying
1. **Props off** → Connect battery → Arm switch → Motors should spin
2. Flip flight mode switch → Confirm OSD shows correct mode
3. Buzzer switch → Buzzer sounds
4. Turtle mode switch → OSD shows “Flip Over After Crash”
5. **Props on** → Fly
A properly configured Modes tab means you always know exactly what your switches do. Take 15 minutes to set it up correctly and it pays off every flight.