I have the Matek Lost Model beeper (https://www.getfpv.com/matek-lost-model-...uzzer.html) that I hooked up to my Mamba F722s flight controller. I set up a switch in Betaflight that would activate the buzzer, but it won't work after much troubleshooting. I'm wondering if I wired the buzzer wrong. I couldn't find much helpful info about the Matek buzzer wiring online.

For the wiring, I followed the below wiring diagram. I wired the B- on the buzzer to the B- pad on the FC, and the B+ on the buzzer to the B+ pad on the FC. I didn't do anything with the Aux, 5V, or Ground on the buzzer. What did I do wrong?

   

I assume you have tried with a lipo plugged in?

(25-Mar-2021, 12:54 AM)kafie1980 Wrote: I assume you have tried with a lipo plugged in?

Yep I did.

The official website states that the B+ pad was removed on newer versions because it was useless: http://www.mateksys.com/?portfolio=dbuz5v#tab-id-1

They recommend wiring it as follows:

FC 5V --> Buzzer 5V
FC GND --> Buzzer GND
FC B- --> Buzzer -B

Buzzer to FC

B- to B-
5V to 5V or B+
Ground to ground

You do not need B+ on buzzer or aux.

(25-Mar-2021, 02:41 AM)voodoo614 Wrote: Buzzer to FC

B- to B-
5V to 5V or B+
Ground to ground

You do not need B+ on buzzer or aux.

Since my FC only has two buzzer pads that I'll put the B- and 5V on, do I solder the ground wire from the buzzer to any open ground pad on the FC? Or where is that wire supposed to go?

Any ground will work.

(25-Mar-2021, 04:27 AM)Kevin2112 Wrote: Any ground will work.

I thought the ground side of a buzzer pad was typically the side that 'switched' it i.e., made it beep-beep-beep vs beeeeep?

Any positive will work, but isn't a beeper ground specific?

The B+ pad is just an unswitched 5V pad with a "B+" label that permanently supplies 5V when the FC is powered up. So you can use either the B+ pad or any 5 pad on the FC.

The B- pad is a switched GND pad that is turned on and off by one of the outputs on the MCU via a transistor, so you always need to use that particular pad rather than a normal GND pad otherwise you will just end up with a buzzer that is permanently beeping as soon as the FC is powered up.

Holy cow... so, Snow, I was... correct?! Proud moment

Silly question, it would still beep even if the self contained beeper battery was dead, right?

I've heard of beeper batteries coming DOA, that kinda deflates the porpoise, don't it?

(25-Mar-2021, 02:04 PM)JSchubz Wrote: Silly question, it would still beep even if the self contained beeper battery was dead, right?

I've heard of beeper batteries coming DOA, that kinda deflates the porpoise, don't it?

It depends.

The VIFLY Finder V2 won't work as a normal manually operated buzzer if its mini LiPo is discharged, dead or is disconnected from the board. That particular buzzer is powered directly from the LiPo and the power to the board itself is only for the mini LiPo charging circuit. I have personally had two VIFLY Finders stop working completely due to a dead mini LiPo (one DOA and another that just died in service). I was unable to use them as normal buzzers until I had replaced the mini LiPos with new / charged ones. Then they were as good as new again.

I also have other self-powered buzzers where the mini LiPo died but they still worked just fine as a normal manual buzzer, just without the self-powered backup function. Removing the mini LiPo from those resulted in the buzzers still working as a normal manual buzzer. These were a URUAV UR8 and an Aurora AR Tracker Thin. I've since also fitted new mini LiPos to these so the self-powered backup function is also working again.

So if you want a self-powered buzzer that will still work as a normal buzzer (via your transmitter switch) if the mini LiPo fully discharges or dies, then don't get a VIFLY Finder V2. It's quite disappointing that VIFLY have designed their buzzers that way because other than that flaw they are the loudest of all the self-powered buzzers I have.

Snow, just to add to the list: The Flywoo Finder also functions as a normal buzzer if the integrated lipo battery dies or is removed.

Thanks. It will be good to make a list of buzzers which have / don't have the same flaw as the VIFLY Finder does. I also have a FullSpeed Lucky Box self-powered buzzer on one of my quads but the mini LiPo on that is still functioning just fine so I've not yet been able to verify whether or not it works as a normal buzzer without a working mini LiPo.

We went a bit off topic from the OP's original question but I think that got sufficiently answered a few posts back so any off-topic discussion doesn't really matter now.

(26-Mar-2021, 01:15 AM)SnowLeopardFPV Wrote: Thanks. It will be good to make a list of buzzers which have / don't have the same flaw as the VIFLY Finder does. I also have a FullSpeed Lucky Box self-powered buzzer on one of my quads but the mini LiPo on that is still functioning just fine so I've not yet been able to verify whether or not it works as a normal buzzer without a working mini LiPo.

We went a bit off topic from the OP's original question but I think that got sufficiently answered a few posts back so any off-topic discussion doesn't really matter now.

No worries, I rewired my buzzer as I was told to and it works now!

(25-Mar-2021, 01:36 PM)JSchubz Wrote: I thought the ground side of a buzzer pad was typically the side that 'switched' it  i.e., made it beep-beep-beep vs beeeeep?

Any positive will work, but isn't a beeper ground specific?

The B- is the signal wire not the ground for the buzzer. You need all three wires to work correctly.