FT Turbo Gremlin won't arm

[CptCrazyFingers]

I bought the Turbo Gremlin with the DSMX receiver and had it built by FT. After figuring out how to connect my FPV goggles and how to bind my transmitter to an auto-binding receiver that was not auto-binding, I am now at the point where the quad will not arm. The transmitter I am using is the Spectrum DXe. I plugged the quad into Betaflght, calibrated the accelerometer, ensured that my transmitter is connected and all the stick movements are doing what they should be doing, centered all trims, and successfully tested the motors with the throttle sliders in Betaflight. I even tweaked the lowest throttle limit, moving it above and below my transmitter's lowest throttle reading. The DXe has an arm switch but I don't think its being used. My Aux 1 switch is set in Betaflight as the arm switch and when toggled, the indicator moves into the armed range. My arming disable flags are 4 and 16. I looked these up and 4 is a flag the indicates that the arming switch is off. I have toggled every switch on my transmitter and this flag does not go away. Flag 16 is just there because my quad is connected to Betaflight. Does anyone have any suggestions?

 

[French]

It’s a better fix if you make sure the min command is 1000 and max command is 2000 for the channels in the receivers tab. I think you need to adjust the throws on the radio to ~157% weight.

 

[CptCrazyFingers]

French, thanks for the tips. I will adjust the throttle min/max values. I’m not quite sure I know what you mean by “adjust throws on the radio to about 157% weight” though.

 

[PsyBorg]

In most radios there is a setting called "End point" or "Travel Adjust" this allows you to set how far a servo can travel in a positive or negative direction. For multi rotors that setting is used to allow stick travels to range from 1000 ms to 2000 ms. By default I believe Spectrum and some Flysky radios default that range from 1100 ms to 1900 ms. That is why you have to set that range to ~147% so the flight controllers can read the full range thus allowing that control value to fall back within the default range.

You can adjust the flight controller to work within that range however you lose what is called resolution and will make the sticks far more sensitive because they have a shorter range to work within.

 

[CptCrazyFingers]

Thanks Psy. I am just waiting for a programming cable so I can adjust the travel. Something I should have bought a long time ago but I have only ever needed to reverse the servos and that can be done without plugging it into a computer. Anyway, I hope that's it because I have already confirmed that the throttle, and all other stick movements, are being read by the receiver. I even turned off arming and it still did not arm. I actually thought I was going to have more trouble with video but that was just as simple as looking up the channel settings on my fpv goggles. This video transmitter has a lot more frequencies than my goggles.

 

[CptCrazyFingers]

I figured it out! I got the programming cable for the DXe and I couldn't find any settings for travel adjust in the app that I have to use to program it. I could only adjust expos, throttle cut, and reverse servos. I saw that there is a program that work with Windows so I will have to check that out later but I didn't feel like wasting the 10 seconds required to switch operating systems on my Mac. Anyway, I started looking into the DXe and I did find people saying that you can't adjust travel on this radio. I don't think that's true but I decided to open up Beta Flight and start troubleshooting. I noticed that when I flip the arm switch, the slider would move into the active range but the arm tab would not highlight. I also noticed that my throttle was only going as low as 1050 and the low throttle setting in Beta Flight was 1000 (I lowered it when I first started trying to solve this problem). I moved that up to 1075 and all of a sudden the arm tab was highlighting when the arm switch was in the proper position and the flashing blue light on my flight controller would turn solid. All things that I had not seen up to this point. Now the quad arms! Thanks for all your help everyone!

Interesting side note: Whenever I power on the quad, the wifi speaker that is connected to my house's door and window sensors looses connection. My assumption is that the video signal is interfering with the wifi signal but it's the only wifi device that seems to be affected. It took me 3 days to realize that the speaker telling me it was loosing and regaining connection was related to this. I was blaming it on a bad internet connection at first.