Help! Gremlin Quad Beta flight setup


Im in the process of a 6 month engagement trying to get an FT gremlin quad into the air. Ive already fried the stock hglrc vtx, (rookie mistake) and went and bought a whole different flight stack because I was having such a hard time using the hglrc stack that comes with the turbo gremlin power pack.

So, I recently purchased the luminier lux mini f7 flight stack. I was able to solder everything up no problem but ran into an issue with the uart placement of a Spektrum srxl2 dsmx serial micro reciever spm 4650. Initially I it soldered to tx3 of the lux mini under the direction of josh bardwell. However after that gave no response in beta flight I reached out to the Get fpv people and they pointed me towards the manual and said that there is a dsm pad for these types of recievers. So going against what bardwell said I soldered it up using the dsm pad. And it worked!

For a little..... I was able to put the receiver into bind mode through the beta flight receiver tab, bind it to my dx8 transmitter and register inputs and movement in the receiver tab when I moved the sticks of my transmitter. Then just like that it stopped working, and now I can't get it the the receiver to talk to betaflight again. I can bind the transmitter and receiver together no problem, I just can't get the transmitter to input any signals into beta flight and/or Im assuming the flight controller.

I wondering if it has anything to do with my laptop computer not being able to run beta flight correctly, or maybe its a defective receiver? Looking online I read that sometimes receiver inputs wont be registered if your CPU is too high, mine is around 100 when I try to get the receiver to talk. So in order to get it lower you turn off the accelerometer or mess with loop rates or whatever. I tried, didn't work, so I backed up the flight controller to what it was before I messed with stuff.

I really want to get this thing going, the whole process has been a bit discouraging. Maybe I'll just stick with foam board planes. Lol

Thanks for any help and insight, I really appreciate it!


Wake up! Time to fly!
if you mean 100% on the quad cpu yes that is bad. Its not too great on your lap top either. First thing to check is if the version of betaflight supports the generation of flight controller. If you manage to load a current betaflight version (which you shouldnt) on an early flight controller all the fancy bells and whistles could over tax it.

Did you get the new v2 F7 Lux or my guess since it is cloccking 100% is the old lux (f3 flight controller?) should be supported back at 10.4 (last version to support f3) at the latest. You can download that version from the betaflight wiki.

Next you need to understand these guys (as helpful as they may be) are compensated in some manor to tell you the products they use are the best thing since sliced bread. I still rip my OG Gremlin around on a femto F1 board on 3s and its a fantastic little flyer. I love Bardwell for teaching so much but he relies too heavily on filtering which only manipulates the pids. Yes it is easier, yes it flys smoother, but they still fly like a wet noodle control wise.

I would start by defaulting the controller back to stock specially if you cookie cuttered a Bardwell setup from a more capable FC. I would probably go as far to get back on to a 10.4 .hex for that controller to be sure.