Buzzer for Float Package or 5.3 ATR / 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.

  • 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)

  • Only in 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:



Any reference for the JST connector :}?
A standard JST connector (2mm pitch) will do, correct?
Also, looks like 4-pin to 3-pin is needed to connect to LFOC v3+? Any alternative to going all in w/ having to purchase crimping tool + 100s of wires/connectors :}? E.g. would it make sense to depin/repin existing separate already wired (crimped) 4-pin and 3-pin connectors, thus avoiding the crimping headaches ;)?
Thanks for any insight…

3-pin, no? Servo, 5V, GND. Don’t have a buzzer myself, just going off the diagram. But yes, JST-PH with 2mm pitch

1 Like

3-pin for the LFOC yes. The buzzer clearly has a 4-pin connector, one is unused I guess.

Ah my bad, misread your reply. Honestly, dont take this as an official recommendarion lol, but for these JST connectors I’ve just cut them with cutting pliers to be the right number of pins before lol. Just need to make sure you dont take out the wall of the 3rd pin, and might need to trim material off the top/bottom of the connector so it fits the port. Again, huge grain of salt on that advice :joy:

Proper way would be acquiring a 3pin connector and just re-pinning it, which is extremely easy with these connectors. I just lift the tabs with an exacto knife and pull the wires from the connector, then push them into the new one and they click in

I got the buzzer in the link and just cut the cable it came with and grabbed a 3 pin JST harness that must have came with something I ordered. I soldered the wires based on the diagram and was done.