Buzzer
INAV supports a buzzer, which is used for the following purposes:
- Low and critical battery alarms (when battery monitoring enabled)
- Arm/disarm tones (and warning beeps while armed)
- Notification of calibration complete status
- TX-AUX operated beeping - useful for locating your aircraft after a crash
- Failsafe status
- Flight mode change
- Rate profile change (via TX-AUX switch)
If the arm/disarm is via the control stick, holding the stick in the disarm position will sound a repeating tone.
This can also be used as a lost-model locator.
Startup Tones​
Gyro Calibration Tone​
Three beeps immediately after powering the board means that the gyroscope calibration has completed successfully. INAV calibrates the gyro automatically upon every power-up. It is important that the copter stay still on the ground until the three beeps sound, so that gyro calibration isn't thrown off. If the aircraft's position is significantly altered during calibration, INAV will detect this and automatically re-start the calibration once the aircraft is still again, resulting in a delayed "three beeps" tone. In addition to the delayed calibration beeps, there is a chance the gyro does not calibrate correctly, resulting in poor flying characteristics. In this case, the gyro calibration can be performed manually via stick command, or simply power cycle the board.
GPS Fix Tone​
There is a special arming tone used if a GPS fix has been attained, and there's a "ready" tone sounded after a GPS fix has been attained (only happens once). The tone sounded via the TX-AUX-switch will count out the number of satellites (if GPS fix).
Tone sequences​
The CLI command play_sound is useful for demonstrating the buzzer tones. Repeatedly entering the command will play the various tones in turn. Entering the command with a numeric-index parameter (see below) will play the associated tone.
Buzzer is enabled by default on platforms that have buzzer connections.
Buzzer tone sequences (square wave generation) are made so that : 1st, 3rd, 5th, .. are the delays how long the beeper is on and 2nd, 4th, 6th, .. are the delays how long beeper is off. Delays are in milliseconds/10 (i.e., 5 => 50ms).
Sequences:
| Num | Status | Sequence | Description |
|---|---|---|---|
| 0 | GYRO_CALIBRATED | 20, 10, 20, 10, 20, 10 | Gyro is calibrated |
| 1 | RX_LOST_LANDING | 10, 10, 10, 10, 10, 40, 40, 10, 40, 10, 40, 40, 10, 10, 10, 10, 10, 70 | SOS morse code |
| 2 | RX_LOST | 50, 50 | TX off or signal lost (repeats until TX is okay) |
| 3 | DISARMING | 15, 5, 15, 5 | Disarming the board |
| 4 | ARMING | 30, 5, 5, 5 | Arming the board |
| 5 | ARMING_GPS_FIX | 5, 5, 15, 5, 5, 5, 15, 30 | Arming and GPS has fix |
| 6 | BAT_CRIT_LOW | 50, 2 | Battery is critically low (repeats) |
| 7 | BAT_LOW | 25, 50 | Battery is getting low (repeats) |
| 8 | NULL | multi beeps | GPS status (sat count) |
| 9 | RX_SET | 10, 10 | RX is set (when aux channel is set for beep or beep sequence how many satellites has found if GPS enabled) |
| 10 | ACC_CALIBRATION | 5, 5, 5, 5 | ACC inflight calibration completed |
| 11 | ACC_CALIBRATION_FAIL | 20, 15, 35, 5 | ACC inflight calibration failed |
| 12 | READY_BEEP | 4, 5, 4, 5, 8, 5, 15, 5, 8, 5, 4, 5, 4, 5 | GPS locked and copter ready |
| 13 | NULL | multi beeps | Variable # of beeps (confirmation, GPS sat count, etc) |
| 14 | DISARM_REPEAT | 0, 100, 10 | Stick held in disarm position (after pause) |
| 15 | ARMED | 0, 245, 10, 5 | Board is armed (after pause ; repeats until board is disarmed or throttle is increased) |
You can use this tool to hear current buzzer sequences or enter custom sequences.
Controlling Buzzer Usage​
The usage of the buzzer can be controlled through the CLI using the beeper command.
List current usage​
beeper
List all buzzer setting options​
beeper list
giving:
Available: RUNTIME_CALIBRATION HW_FAILURE RX_LOST RX_LOST_LANDING DISARMING ARMING ARMING_GPS_FIX BAT_CRIT_LOW
BAT_LOW GPS_STATUS RX_SET ACTION_SUCCESS ACTION_FAIL READY_BEEP MULTI_BEEPS DISARM_REPEAT ARMED SYSTEM_INIT
ON_USB LAUNCH_MODE CAM_CONNECTION_OPEN CAM_CONNECTION_CLOSED ALL PREFERED
The beeper command syntax follows that of the feature command; a minus (-) in front of a name disables that function.
So to disable the beeper / buzzer when powered by USB (may enhance domestic harmony):
beeper -ON_USB
Now the beeper command will show:
# beeper
Disabled: ON_USB
Note: SYSTEM_INIT sequence is not affected by ON_USB setting and will still be played on USB connection. Disable both ON_USB and SYSTEM_INIT to disable buzzer completely when FC is powered from USB.
Note: ON_USB setting requires present and configured battery voltage metter.
To disable all features use:
beeper -ALL
To store current set to preferences use (preferences also require save):
beeper PREFERED
To restore set from preferences use:
beeper -PREFERED
To activate an external beeper via aux channel switch, assign aux channel and set both:
beeper RX_SET
beeper MULTI_BEEPS
If MULTI_BEEPS is not set, the beeper will not sound after GPS lock.
As with other CLI commands, the save command is needed to save the new settings.
Types of buzzer supported​
Most FCs require ACTIVE buzzers. Active buzzers are enabled/disabled by simply enabling or disabling a GPIO output pin on the board. This means the buzzer must be able to generate its own tone simply by having power applied to it.
Passive buzzers that need an analog or PWM signal do not work and will make clicking noises or no sound at all.
Passive buzzers are supported on FCs which are designed to work with passive buzzers only (so far there is no available, except rare cases like Matek F765-WSE where passive buzzer is preinstalled).
Examples of a known-working buzzers.