5 ms·
This is all true, but just to set expectations: the open source ecosystem seems to be lagging the proprietary world pretty significantly, unless there's some co
by Kadin 2y ago
This is all true, but just to set expectations: the open source ecosystem seems to be lagging the proprietary world pretty significantly, unless there's some corner where development is really chugging along that's not making it out to the rest of the hobbyist market.
Though there have been incremental improvements in flight control software, and video subsystems have moved (mostly) from analog to 2.4/5.8 GHz and digital, the overall architecture is pretty similar to what it was 5+ years ago. You have a hobby R/C transmitter and receiver driving PWM outputs (through the flight controller, typically an STM32) to hobby-type ESCs which control the motors. The ESCs are microcontroller-driven and can be reflashed, but painstakingly and annoyingly. Telemetry is typically separate from control, which is separate from video. Everything is very short-range and non-IP.
In comparison, a COTS quadcopter from DJI has a single backhaul from the airframe to the controller which does control, video, and and telemetry. And the video is impressively low-latency. (I'm pretty sure they use a WiFi-type chipset and just spew raw vendor frames, and the receiver picks up what it can, best effort. You could do this with an ESP32 in ESP-NOW mode, I suspect?) I've seen some efforts to reverse-engineer the DJI protocol but I'm not aware of a fully compatible implementation or equivalent in the OSS world.
And at the upper end of the commercial/proprietary space you have systems with out-of-the-box autonomy, multiple backhauls over IP -- so they can use LOS/BLOS radio, LTE, SATCOM, whatever you want -- integration with navigation beacon systems to reduce GPS dependence, hybrid motor/generators, redundant power systems, the whole shebang.
There's no real reason aside from developer interest that this situation exists, as far as I can see. The components are mostly all available. A Raspberry Pi running a decent RTOS would have orders of magnitude more processing capacity than an STM32 and could easily do the sort of multi-sensor fusion that the commercial systems do. LTE modems are cheap. A bigger hexacopter or fixed-wing could easily loft one of the small Starlink dishes, if someone wanted to. Stuff like "perching" (landing and recharging from solar panels) is entirely possible.
But from what I can tell, the cutting edge of open source drones is happening behind closed doors in Ukraine and Iran.
Happy to be corrected if there's new stuff that I'm not tracking, but the gap between the "art of the possible" and current practice seems large.
Lots of opportunity though, is the other way to view it.
- the__alchemist 2y agoThat is consistent with my experience. My highlights: - Current betaflight devevelopers and leaders are incompetent (They inherited the code base from others), and are slow, and varying degrees of willing, to add higher-level flight-control mechanics (semi-autonomous modes etc). - The Ardupilot and PX4 configuration systems, and general experience, are user-hostile. Note that the converses of these hold: Betaflight has a reasonably-good user experience, and Ardupilot and PX4 have extensive higher-level flight control mechanics. If only you could get the pros of both together! Regarding hardware, frames generally accommodate flight controllers and ESCs elegantly, but other hardware like cameras, radios, and especially batteries, feel clumsy to assemble in a safe and consistent way.
- bodhi_mind 2y agoFwiw, betaflight for acro flight is probably the best. Tuning is dead simple. Filtering is possibly the best. That said, I don’t need much else because I just fly acro mode 100% of the time.
- aftbit 2y agoI haven't touched this stuff in 5+ years, but I wonder how iNav stacks up on your list? I was about 50% of the way through a 7" FPV build with a GPS receiver based on iNav when COVID hit, and between the supply shortages and general life shift, I stopped working on it.
- the__alchemist 2y agoI'm curious too; of those it's the one I have the least experience with. It is currently not an option for me, as the aircraft I would use with it uses CAN perhipherals, which iNav doesn't support.
- 83 2y agoI fly iNav on a couple planes. I havent updated to the latest version in a couple years but i find it works great. The electronics like gps modules and sensors are insanely cheap now if you go straight from china (aliexpress) - you can get an hglrc m100 gps for about $12 shipped now.