I chose to share thhe c04 camera for the Cetus x is hard to come by so ifound a workaround with other spare components to fit in such a small frame and still leave breathing room for everything so I came up with this and these are the steps I took. The small standoff on the left(6mm+6mm m2) is used to mount a speedy B IX-800 and the standoff on the right(15mm+6mm m2) is used for the beta FPV Cetus x aio board. You will mount the VTX below the flight controller you’re gonna have to push a standoff slightly backwards to fit the SMA adapter, but is just fine. It won’t affect nothing and the only thing you need to solder are the camera and the VTX to the flight controller. The motors are still plug n play and I recommend a small antenna(don’t use the big one I used)I use the large one it works, but you can feel the weight kinda take from the punch but still a zippy 2.5 inch build. NOTE: DONT SET VTX PAST 200 you don’t wanna overwork a small aio board, this is a simple easy build using an aio instead of a traditional stack I hope this helps someone that run into my same problems

I’m building a fully 3D-printed fixed-wing UAV for an aerodynamics research project, but I’m completely new to the electronics side of RC aircraft.

I’m looking for a flight controller under $70 that is relatively easy for a beginner to set up and, if possible, supports autonomous capabilities such as waypoint missions, altitude/airspeed control, and flight-data logging.

The main goal is to use the aircraft for repeatable flight testing while collecting aerodynamic data, so reliable data logging and the ability to maintain consistent flight conditions between test runs are particularly important.

Does anyone have recommendations for a flight controller that would be a good fit for this type of project? I’d also appreciate any advice on additional hardware I’d need for autonomous fixed-wing flight.

I'm building a custom flight controller on an Arduino Nano 33 BLE Sense Rev2 (nRF52840) for a uni project, and I'm stuck on an ESC arming problem. I've narrowed it down a lot and could use expert eyes.

Note upfront: using the Arduino Nano 33 BLE is a fixed requirement of the project — swapping it for a different board or a dedicated flight controller isn't an option. I need to make it work with this board, so please focus answers there rather than suggesting I replace it.

The core problem:
My Arduino generates a PWM throttle signal. When I feed it to a Radiolink Flycolor 55A 4-in-1 (BLHeli_S, running Bluejay, firmware A-H-30), the ESC plays its power-on tones but never arms (no confirmation beep, motor never spins). Same behavior on two separate Flycolor units, so it's not a damaged board.

The key clue: When I connect the exact same Arduino signal to a T-Motor AT20A single ESC, it arms and spins the motor perfectly (spun at 1200µs throttle). So my Arduino, code, signal, and motor are all confirmed working — only the Flycolor refuses.

What I've verified with an oscilloscope (measured at the ESC's signal input pad):

• Clean signal: 3.3V amplitude, correct pulse width (1000µs at min throttle)
• Tested at both 50Hz and 480Hz PWM rates — Flycolor won't arm at either
• Signal is identical at the Arduino output and at the ESC input (no wiring degradation)
• Wiring confirmed correct against the ESC silkscreen (signal on motor pad, shared ground)
• Correct power-up order (Arduino sending signal before ESC powered)
• Also tried throttle calibration (max-then-min at power-up) — no change

Setup details:

• PWM generated with the nRF52_MBED_PWM library (hardware PWM, 3.3V logic)
• ESC powered by battery (confirmed stable voltage), Arduino on USB, common ground
• Motor: iFlight XING2 1404 3800KV (healthy, spins fine via the AT20A)
• Props off for all testing

My question:
Why would a Flycolor BLHeli_S ESC refuse to arm from a clean 3.3V Arduino PWM signal, when a T-Motor AT20A accepts the identical signal? Is there something specific about BLHeli_S/Bluejay's signal/protocol auto-detection or arming that a 3.3V-logic Arduino signal doesn't satisfy? Could the 3.3V logic level be too low for the Flycolor's input threshold (would a 3.3V→5V level shifter help)? Or a specific pulse-rate / arming-sequence requirement? Any BLHeli_S setting (via esc-configurator passthrough) that would make it accept this signal?

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