Hi to all. I would like to know wich buzzer wire carries the signal on betaflight : positive or ground?
I am tryng to install this led/buzzer via pdb 5v line to not overload fc bec :

https://m.banggood.com/RC-Tail-LED-Light...48045.html

Wich buzzer wire from fc i have to hook up on this led buzzer pad? Black- or red+?
Thanks in Advance!

Look on the back, you have 4 pads. + (red) & - (black) are connected to 5 volt power supply on your pdb. Buzzer goes to buzzer pad on your flight controller. It will work just fine like this, but you also have the option of connecting the DIN pad to the LED pad on your flight controller for more advanced light shows

(28-Oct-2017, 02:04 PM)RENOV8R Wrote: Look on the back, you have 4 pads. + (red) & - (black) are connected to 5 volt power supply on your pdb. Buzzer goes to buzzer pad on your flight controller. It will work just fine like this, but you also have the option of connecting the DIN pad to the LED pad on your flight controller for more advanced light shows

Thanks. I will connect led din pad. But my doubt is wich wire from fc i have to solder to the single pad on the led/buzzer device.in the fc i have two buzzer pads (xracer f303)
+ and - and on buzzer i have a single pad....

The buzzer pad is marked "-", so you should connect the BUZ- pad on the X-Racer to the buzzer pad on the board. The 5V to the board will provide the + connection to the buzzer.

Ok it was what i wanted to be sure because the printing on buzzer pdb is not perfectly readable. It is just a small dot instead a ground sign.
So the "signal" wire from fc is the negative!
Thank you vera much! !!

(29-Oct-2017, 09:35 AM)lorentz Wrote: Ok it was what i wanted to be sure because the printing on buzzer pdb is not perfectly readable. It is just a small dot instead a ground sign.
So the "signal" wire from fc is the negative!
Thank you vera much! !!

The pad actually goes to a transistor. Because a buzzer pulls more current than a pin on the MCU can deliver, the buzzer signal turns a transistor on and off. Your buzzer is connected between the 5V supply and the transistor which sinks the current to ground when the flight controller turns it on.



This is why you can't re-map the buzzer pin.

Thanks for the great explanation!
I will solder the 5v positive and negative coming from the pdb bec, din from fc and negative from buzzer pin on fc to buzzer pad.
Hope it will works.
Thanks again