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sp F3 femto (gremlin) low batt buzzer as lost quad buzzer?

pinpoint45

Pants Wearer
#1
so i noticed that the FC has the ability to buzz when the vbatt is too low. is it at all possible to access that buzzer to be used on for example Aux2 as a lost model buzzer? is it something that will require CLI coding? is it just not possible? i have tried setting the channel switch in the modes menu of betaflight, but it just turns on the Red board LED. much thanks to anyone who can help me out on this.
 

pinpoint45

Pants Wearer
#3
i might not have explained well enough, but in the original post i said that i tried enabling that in the modes menu and the result was just the red indicator light started flashing. i found out tonight that there is a pad on the back of the FC for a buzzer, but i'm already pressed for room on TJ's frame and im looking for a way to use the BEC buzzer if possible.
 

JimCR120

Got Lobstah?
Site Moderator
#4
Hmmm, I'm thinking a flashing red light offers very limited aid in finding a lost quad... unless it was pitch black outside.

I like the idea. Certainly there must be a way to employ such a useful feature.
 
#6
I'm not sure about using a BEC buzzer. The ESCs that come with the Gremlin kit don't have a buzzer. Some ESCs have a low-volatage buzzer but most ESCs only send signals to the motors to create the beeping sounds.

The buzzer pads on the bottom of the Femto F3 are for a small 5V buzzer like these. Every time the red LED on the FC lights up, it sounds the buzzer. Since you see the flashing red light, you know you have programmed it correctly in the betaflight modes. You just don't have a buzzer hooked up to those pads.

I bought a 5-pack of buzzers and put one on another quad running betaflight and set it up on AUX2. Works like a charm and I just hot glued it to the base plate between the arms. I haven't installed it on my gremlin yet, but you are right, there is not a whole lot of real estate left on the TJ frame even though they are the size of a toothpaste cap.
 
#8
i might not have explained well enough, but in the original post i said that i tried enabling that in the modes menu and the result was just the red indicator light started flashing. i found out tonight that there is a pad on the back of the FC for a buzzer, but i'm already pressed for room on TJ's frame and im looking for a way to use the BEC buzzer if possible.
I just finished putting together a Gremlin with TJs frame. I used the tiny SBUS XM receiver for my FRSky and had no problems fitting an actual buzzer next to it between the FC and the frame top plate. This allows me to use the buzzer for low voltage as well as on a switch. Worked well.
 
#10
I just finished putting together a Gremlin with TJs frame. I used the tiny SBUS XM receiver for my FRSky and had no problems fitting an actual buzzer next to it between the FC and the frame top plate. This allows me to use the buzzer for low voltage as well as on a switch. Worked well.
Cool. Although, I'm a bit fuzzy on how you laid everything out. Could you share a picture of this setup?
 
#11
As bad as I fly, I wouldn't fly anything without a buzzer,they are a life saver on this little things. When I first started trying fpv I spent over an our looking for one of the little brushed motor quad, and that taught me a lesson. Now they all have a buzzer set up for my lost quad. If there is no room I'll make room.
IMG_0027.JPG
 
#12
#13
Need to change Betaflight settings after connecting to Femto beeper pads

Just a note that Betaflight doesn't always beep when receiving aux. In addition to mapping the channel, you need to enable aux beeper in the CLI:

beeper RX_SET
save