Buzzer for ATR and 5.3v6 firmware

What is the buzzer?

A small device that beeps when stuff happens

How do I get one?

Any device that emits noise (or light if you prefer that) when 3.3V is applied and is silent when 0V is applied can be used. The one I like is a Grove Active Buzzer:


How to hook it up?

I'm using the servo pin for this purpose. So the servo pin controls the beep, while GND/5V power the beeper. It is also possible to power it straight from the servo pin but some buzzers may not be loud enough at 3.3V.

What firmware do I need?

The buzzer only works on surfdado firmware. Why not on standard firmware? Because Mitch no likey :)

Also: to enable it: in App-General set Enable Servo to TRUE

What's the behavior?

Here's the list of situation when it beeps:
  • Constant beep when foot sensor fault detected at speed (beeps only exactly as long as you’re off the pads), consider checking your sensors or lowering your adc switch values

  • Duty tiltback angle set to 0? It will beep instead whenever you hit or exceed your duty cycle tiltback threshold

  • Triple-beep when high voltage tiltback triggered, triple-beep on low-voltage

  • On boot: short beep when VESC boots, long beep when balance app is ready (and each time you write app config!)

  • Beeping when 2-3 degrees away from overtemperature throttling

  • LV beeps on boot: Are we less than 5V above LV tiltback threshold? Issue 1 beep for each volt below
    that level.

  • Attempting to write config while riding? 3 long beeps tell you “nope”

  • 10 seconds after you step off your board: if you’ve ridden 100m or more you’ll hear one short beep telling you that the odometer has been updated in permanent storage (it’s not a good idea to update it there constantly because the type of memory used has a limited number of times it can be written to, hence this behavior)

  • Since ATR23: 6 short beeps when you mount your board with an ERPM limit of <= 10k configured


Here’s how to wire the LFOC servo connector to the Seeed Grove Buzzer: