DTF SEPPUKU and dRonin – Made For Each Other
If you’ve been around a while then you’ve probably heard of DTF Air. These guys not only created the DTF UHF long-range radio gear, but also the OSDoge plug-and-play Naze32 OSD/PDB. They’ve been around a while is what I’m saying, and they are known for making quality gear. When I heard they were making a new flight controller, and specifically for use with the dRonin firmware, my interest was piqued. I got in touch and they were very kind to let me get my hands on the new “Seppuku” flight controller. What a name!
The Seppuku features an STM32F405 processor, up to 5 serial ports, integrated OSD, a BMI160 gyro and accelerometer, integrated baro and compass, up to eight PWM outputs, RGB status LED, WS2812 LED controller, voltage monitoring, current monitoring support – [retty much everything a modern flight controller should have and more. All of this results in a flight controller that feels at home on a racer, a large octocopter, or even an FPV wing. All in a standard footprint, and for only $60.
The board arrived in some of the most creative packaging I’d seen for a flight controller. A small burlap sack with the logo printed on the front, a title card, and inside an info card and the flight controller in an anti-static bag. I’m not sure what I’ll use the little bag for, but it’s the first bit of flight controller packaging that I won’t throw away! “Reduce, Re-use, Recycle”, friends – Cheers to less waste!
DTF Air has made a commitment to use locally-sourced components and labor, and honestly this hobby could use more of that. The Seppuku was designed in California and manufactured in Quebec, Canada. All of the components appear to be high quality, and the soldering looks sound resulting in a very nice looking board.
Having gotten used to building with stackable combos like the RE1 and mPB, it took me a moment to remember how to solder up a flight controller. Luckily both sides of the board are labelled at the solder points, which really helps when building as you can look at either side to run your wires. 5v to the 5v pin, battery voltage to the voltage sensor, motors – it’s all pretty standard wiring. There is a dedicated port for the receiver (PPM or serial) with either 3.3V or 5V. There is a small pad to bridge that allows you to choose the power output. If you haven’t used a board with an integrated OSD yet, know that you run power to your PDB, but ground and video goes to the FC.
With everything wired up it is easy to configure the aircraft in dRonin. Like, ridiculously easy. If you remember OpenPilot then you’ll feel right at home in dRonin. When you first connect to dRonin it will check your firmware version. If there is a newer version then it will prompt you to update. dRonin uses a cloud service to validate your current settings and, if needed, will automatically update them to be compatible with the new firmware. It will even allow you to dump a backup before writing any changes.
Using the Vehicle Setup Wizard, dRonin GCS will walk you through the entire process of configuring your aircraft up to the point of assigning your chosen flight modes. It will set up your radio, calibrate your ESCs, and prepare you for basic flight. I recommend using this wizard to get you started, and then delving into the configuration tabs and making adjustments to suit your needs.
The Seppuku has multiple serial ports that can be used for a multitude of functions. dRonin was one of the first open source firmwares to support TBS SmartAudio, the protocol that allows you to configure TBS Unify Pro video transmitters via their audio channels directly from the flight controller. By connecting a serial port to the my TBS Unify Pro HV audio channel I can change band, frequency, and even transmit power right from the OSD. Another serial port can be used for FrSky telemetry. Building a larger aircraft? Use another port for GPS and still have room for something else.
dRonin also has an autotune feature that works very well in my experience. It is a module that you enable and a flight mode you set. Take your aircraft up, flip to autotune, and let it do its little dance for around 60 seconds. When it’s done you land, disarm and disconnect power, and then reconnect to the GCS software. It will detect a tune and make use of their cloud service to calculate your optimum settings, and then allow you to apply them. It works very well, resulting in a very nice tune. Is it perfect? Probably not, but it’s a good starting point.
In flight, the Seppuku performs admirably. It is getting difficult to tell flight controllers apart based on flight characteristics alone, since one you cross a certain quality threshold they should all fly well with a decent tune, but it is still worth noting. It all comes down to firmware and PIDs.
Going back to the OSD, dRonin has one of the best that I’ve seen. It isn’t based on MWOSD, and it is more complete than the current Betaflight offering. You can configure the position of each item individually, and there are a LOT of options to choose from. The refresh rate is crazy fast, definitely one of the most responsive I’ve seen. The default HUD looks like you’re sitting in the cockpit of a fighter jet, which is impressive but distracting. I usually end up disabling everything except the basics like power, RSSI, and my VTX info. My only complaint with the OSD is that the interface in dRonin is lacking – there’s no drag-and-drop editor like in Betaflight, so I end up configuring the OSD with a powered-up quad sitting on my desk broadcasting to an LCD (Props off, obviously). This isn’t a limitation of the Seppuku, but of dRonin…
…and therein lies the rub. The Seppuku is a high end flight controller, full of potential. It can be used on a racer, a flying wing, anything really, but currently it only supports dRonin. dRonin shows a lot of potential and I am a huge fan of how easy it is to use. The autotune procedure is the only one I’ve ever used that actually works… but I’m afraid it may hold dRonin back if it can’t keep up with other firmware options.
Don’t get me wrong, I think there is room in the landscape for a new firmware – something not originally based on BaseFlight, itself based on the old MultiWii code. Perhaps I’m judging dRonin too harshly too soon. When it was fresh and new I ran it on the RE1 and loved it, but have since gone back to BetaFlight because, well, it’s BetaFlight.
That being said, I hope dRonin succeeds. I hope the Sepukku succeeds. I also hope the Seppuku adds BetaFlight support, but only because I want the option. Maybe I’m just spoiled. I can live with dRonin because it works, and it works well. It is easy for a new pilot to get flying if they choose the right hardware, and doesn’t require a lot of previous knowledge to get started. Kudos to dRonin and DTF Air for doing something new and taking a gamble while trying to innovate. I honestly hope it pays off!
The Seppuku is a high-end, high-quality flight controller by a respected designer. It features every sensor you could possibly want in a racer or freestyle aircraft, plus a few more, and would feel right at home in anything that flies. It’s well made and I respect DTF Air for their manufacturing practices. If dRonin can life up to its potential as a firmware offering then this will be a solid performer.
The Seppuku is available at AIRDTF.com
Need help setting up dRonin on your SEPPUKU flight controller? Check out my handy “How To” video HERE on YouTube!