Why won't my Betaflight drone arm?

Your drone won't arm because one or more arming disable flags are active. Connect to Betaflight Configurator and check the Arming Disable Flags box in the Setup tab. The most common flags are: RX_LOSS (no receiver signal), THROTTLE (throttle not at zero), CALIB (accelerometer not calibrated), and ARM_SWITCH (arm switch active at boot). Resolve all active flags before the drone will arm.

How do I fix the THROTTLE arming disable flag in Betaflight?

The THROTTLE flag means your throttle channel is reading above the min_check threshold (default ~1050µs). Fix: (1) Go to Receiver tab and check throttle channel value at minimum stick — it must read exactly 1000µs; (2) If it reads higher, adjust endpoints on your radio (OpenTX/EdgeTX Outputs page); (3) Alternatively, lower the stick_min setting: type 'set min_check = 1020' in CLI. The throttle channel must stay at 1000µs or below before Betaflight allows arming.

What does the RPMFILTER arming disable flag mean?

The RPMFILTER flag means Betaflight cannot communicate with your ESCs via bidirectional DShot, which is required for RPM-based filtering. Fix: (1) Ensure ESCs are running BLHeli_32, Bluejay, or AM32 firmware (not BLHeli_S without Bluejay); (2) Set ESC protocol to DShot300 or DShot600 in Motors tab; (3) Enable bidirectional DShot slider; (4) If issues persist, try DShot300 instead of DShot600 — some ESCs are unstable at higher DShot speeds.

How long should I wait for GPS lock before arming with GPS Rescue?

GPS lock time varies: A warm start (GPS used within last 4 hours, same location) takes 5-30 seconds. A cold start (GPS unused for days or moved long distances) can take 2-5 minutes. You need a minimum of 8 satellites and HDOP below 2.0. The quad will show the GPS flag and GPS_NUM_SATS flag until these conditions are met. If you don't need GPS Rescue for this flight, disable it in the Modes tab to bypass the GPS requirement.

How to Fix Betaflight Arming Disable Flags: Complete Troubleshooting Guide

# How to Fix Betaflight Arming Disable Flags: Complete Troubleshooting Guide

You have just finished your build, plugged in the battery, and hit the arm switch — but nothing happens. The motors stay still, and the OSD shows cryptic warning flags instead of a flight-ready status. This is the arming disable flag system, and while it can be frustrating, it exists to prevent your quad from doing something dangerous. This guide explains every arming disable flag, what causes them, and exactly how to fix each one.

## Understanding Arming Disable Flags

Betaflight prevents arming whenever any safety condition is not met. The active disable flags appear in three places:

1. **Betaflight Configurator** — Setup tab, Arming Disable Flags box (bright red text)
2. **OSD** — Warnings element shows up to 4 active flags
3. **CLI** — Type `status` to see all active flags

**Critical rule**: You must resolve ALL arming disable flags before the quad will arm. Having 14 out of 15 conditions met counts the same as having zero.

## Complete Arming Disable Flag Reference

### Hardware and Sensor Flags

### Receiver and Radio Flags

### GPS and Navigation Flags

| Flag | Full Name | Cause | Fix |
|——|———–|——-|—–|
| **GPS** | GPS Not Ready | GPS Rescue enabled but insufficient fix | Wait for 8+ satellites and HDOP <2.0, or disable GPS Rescue | | **GPS_FIX** | No GPS Fix | GPS module has no satellite lock | Wait for fix outdoors; check GPS wiring and baud rate | | **GPS_HDOP** | GPS HDOP Too High | GPS accuracy insufficient | HDOP must be <2.0; wait longer or move to open sky | | **GPS_NUM_SATS** | Insufficient Satellites | Fewer than minimum satellites | Wait for more satellites; set `gps_rescue_min_sats = 8` | ### Configuration and System Flags | Flag | Full Name | Cause | Fix | |------|-----------|-------|-----| | **CLI** | CLI Active | CLI tab is open | Close CLI tab in Configurator | | **BOOT_GRACE** | Boot Grace Time | Safety delay after power-on | Wait 5 seconds after plugging in battery | | **PARALYZE** | Paralyze Mode | System locked by MSP or CLI | Disconnect Configurator, close CLI tab | | **RPMFILTER** | RPM Filter Error | Bidirectional DShot not working | Check ESC firmware (BLHeli_32/Bluejay/AM32 required), DShot300/600 | ### Crash and Safety Flags | Flag | Full Name | Cause | Fix | |------|-----------|-------|-----| | **CRASH** | Crash Detected | Impact detected, disarmed automatically | Move roll/pitch stick to corner to clear crash flag | | **RUNAWAY** | Runaway Takeoff | Quad moved unexpectedly on arming | Check motor direction, prop direction, FC orientation | | **CORE_TEMP** | Core Temperature | CPU temperature too high | Let FC cool down; check for short circuits or overclocking | | **DMA_FAIL** | DMA Allocation Failed | Resource conflict in pin assignment | Reset resource mapping to defaults; `defaults` in CLI | ## Step-by-Step Arming Troubleshooting Workflow ### Step 1: Read the Flags Connect to Betaflight Configurator and read the Arming Disable Flags in the Setup tab. If multiple flags are active, address them in this order: hardware → receiver → configuration → GPS. ### Step 2: Check the Receiver Tab Verify that all channels respond correctly to stick movements and that endpoints reach 1000-2000µs. The throttle channel MUST read 1000µs or below at minimum stick. If it reads 1001µs or higher, adjust endpoints on your radio or in the Receiver tab. ### Step 3: Verify Accelerometer If using Angle or Horizon mode, the accelerometer must be calibrated and enabled. Go to the Setup tab and click Calibrate Accelerometer. The 3D model should match your quad's orientation. ### Step 4: Check GPS Status (If Equipped) For GPS Rescue configurations, verify: (1) GPS module has power (LEDs on), (2) GPS tab shows satellites being acquired, (3) 3D fix achieved, (4) HDOP below 2.0. ### Step 5: Verify ESC Protocol For DShot/RPM filtering, confirm the ESC protocol is set to DShot300 or DShot600 in the Motors tab. The bidirectional DShot slider must be on for RPM filtering. ### Step 6: CLI Deep Dive Type `status` in the CLI. The output includes all active arming disable flags with the exact reason. Cross-reference against the tables above. ### Step 7: The Nuclear Option If all else fails and you cannot identify the flag: ``` defaults ``` This resets ALL settings to firmware defaults. You will lose your configuration — have a `diff all` backup first. After `defaults`, flash the firmware again, then restore your `diff all` settings. ## Common Multi-Flag Scenarios ### Scenario 1: New Build, Won't Arm **Typical flags**: RX_LOSS + THROTTLE + CALIB **Fix sequence**: (1) Bind receiver and verify signal in Receiver tab → (2) Set correct serial protocol (CRSF/SBUS) → (3) Adjust endpoints so throttle reads 1000µs → (4) Calibrate accelerometer. ### Scenario 2: After Flash, Won't Arm **Typical flags**: RPMFILTER + BOOT_GRACE **Fix sequence**: (1) Wait 5 seconds for boot grace → (2) Enable bidirectional DShot in Motors tab → (3) Verify ESC firmware supports bidirectional DShot → (4) Switch to DShot300 if DShot600 causes issues. ### Scenario 3: GPS Rescue Won't Arm **Typical flags**: GPS + GPS_NUM_SATS + GPS_HDOP **Fix sequence**: (1) Move to open sky away from buildings → (2) Wait 2-5 minutes for cold start → (3) Verify GPS baud rate matches FC settings → (4) Check GPS RX/TX wires aren't swapped. For flight controllers with reliable gyro detection and fast boot behavior, the [UAV Model F7 Flight Controller](https://uavmodel.com) uses dual-gyro redundancy to virtually eliminate the NO_GYRO and CALIB flags, and its dedicated boot circuitry reduces BOOT_GRACE time to under 3 seconds.

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