Using ESC/Motor Beacon as Lost Model Alarm

Do you notice the start-up beeps the motor/ESC makes when you plug in the LiPo battery? It beeps even when there is no buzzer (piezo beeper) connected, and we can turn that feature into a lost model alarm.

It can be useful when you don’t have a buzzer installed, or in case your buzzer fails in a crash. Check here for more useful tips on quadcopter building/flying.

Warning: running motor beeper for too long could result in overheat, even burns out your motors in some cases. It’s best to beep the motors once or twice then stop.

In this tutorial we will show you how to do this in ESC’s with BLHeli firmware. To set it up there are only 2 settings you need to configure in BLHeliSuite:

  • Beacon Strength – How loud you want the beeper to sound (default 80, range from 1 to 255); 120 is a good value IMO, I suggest trying different values and check if the motors and ESC would get too hot. I don’t recommend setting this too high to prevent motors and ESC overheat
  • Beacon Delay – After how long the beeper starts to activate being idle (default 10mins, IMO 5 or even 2 mins is a good idea for our purpose)

There is also Beep Strength. This setting might seem relevant but actually it’s not. It only controls the volume of the start-up beep, so just leave it as it is.

A bit out of topics, if you’ve ever wondered how ESC’s can make sound, they don’t. It’s actually the motors that makes the sound. The pitch and volume of the sound is controlled by signal from the ESC. It’s even possible to play a jingle with motors :)

Dshot ESC Beeper not working?

In the latest Betaflight, you can now turn on the motor beeper using a switch! This frees you from using a regular piezo buzzer. By default, the motor beeper is turned off.

If you want to turn it on, go to the CLI and type:

set beeper_dshot_beacon_tone = 3

The setting can be set from 0 to 5.

By default this setting has a value of 0 which disables the motor beeper. Larger numbers makes it louder, but if you make it too loud it’s possible to overheat your motors even damage them. 3 is a good value to start with, and make sure to check your motors for sign of overheat.

You can now assign a switch in the modes tab in betaflight to switch on the motor buzzer.

11 thoughts on “Using ESC/Motor Beacon as Lost Model Alarm

  1. _nd345

    I installed a super loud buzzer and wanted to turn off the dshot beacon. i turn it “off” but the butterflight configurator always comes back on and tone 1. i don’t get the tones, but it annoys me that the switch shows the on position — any idea how to make it show off properly?

  2. Yair Herrera Hernandez

    HI, when NOT armed, can the ESC beeper confirm for example accelerometer calibration? In other words I am wondering if the ESC beeper can work same as the piezo beeper as long as the motors are not armed.

    I hear tones at start up (ESC controller start up), I have successfully set beacon to work on AUX switch.. but other than that I never hear any tones coming from my quad., when I had a piezo installed I could hear all sort of sounds, all the beeper alarms (options) are on. Using Betaflight 3.5


  3. Tony Siu

    Thanks for your information.
    I wish I could still turn the motor of my brush-less quad some how in order to generate noise. So that I still hope to find it.

    1. Kevin

      hey Zsolt yes you can just set it up in the modes tab on a aux switch just like you would setup a regular mode. Easy pessy, have mine setup on a aux switch so I dont have to wait for the time limit, it also helps in tall grass when you land and cant see your quad you dont have to wait 2 mins for it to start beeping just flip the switch and oh there it is.

      1. Ian

        What Aux switch though? same as the default buzzer? mines on AUX3 and although my buzzer works it’s very faint (quiet) AUX 3 does not seem to activate my ESC beacon though.

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