Buzzers for quadcopter is one of the most basic hardware in the hobby, but a few beginners are still getting confused. So hopefully this article can help clarify a few things.
Purpose of buzzer on a quadcopter
- Lost model alarm – helps you to find your quad in bushes after it’s crashed
- Voltage low warning – buzzer goes off when battery voltage is low
- Quad status – the beeping can help you identify what state the quad is in, e.g. when the quad is ready to arm it beeps 3 times; when there is a problem with receiver connection, it beeps non-stop etc
Choices of buzzer
There are 2 types of buzzers, Active and Passive.
Basically, active buzzers beeps as soon as you give it DC voltage, while passive buzzers require an AC “sound signal” for it to generate sound. Quadcopter flight controllers usually support 5V 2-pin active buzzer/beeper. These buzzers are cheap, light weight and widely available online.
If you are still wondering which type of buzzer to get, just get active buzzers.
Here are some basic 2-pin active buzzers that should work on most quadcopter flight controllers:
Matek makes some really cool buzzer designs. For example this “Loud buzzer” works as a normal buzzer, and can also be controlled via a AUX channel (PWM signal) at the same time.
And this “LED tail light buzzer” is like the last one, but combines with RGB LED’s which can be mounted on the back standoffs.
Don’t confuse yourself with LiPo voltage alarm/checker with the type of buzzers we are talking about here. Voltage alarms are equipped with speakers but they are meant to connect to the balance lead and read the voltage. Other ways to monitor quadcopter voltage.
How to use buzzer on quadcopters
Most flight controllers have dedicated pins for connecting the buzzer, normally labelled as B+ and B-, or similar. For example:
How to make buzzer louder?
- Connect multiple buzzers in parallel, for example.
- Use higher voltage rated buzzer, and provide higher voltage to it, such as using 12V in this example.#
How to make buzzer quieter?
If you don’t like how loud these buzzer is, you can simply put a resistor in series to the positive or negative pin. This will reduce the current flowing through it and lower the volume. The larger resistor the more effective it will be.
As a lost model alarm, you could setup your ESC beeping as an alternative to buzzer: Using ESC Beacon as a lost model alarm