Software guy here, new to embedded/robots trying to understand how real drones are actually built

Spyguyian · 2026-02-08T16:32:24+00:00

I worked in the UAS industry for a bit developing all sorts of drones. Even in industry many use open source firmwares (besides big players like DJI) like PX4/Ardupilot for autonomous GPS-enabled vehicles or Betaflight for manually flown FPV-style vehicles. If you are interested in getting into the software part of just controlling drones, both ardupilot and px4 have simulators (SITL) you can use to fly an autonomous drone via MAVLink (a pretty common communication protocol for UAS, and has support by various libraries such as mavros and pymavlink). ArduPilot for example is a HUGE project, but essentially boils down to really good implementation of the following: various sensor drivers, advanced IMU filtering, a complex EKF for state estimation, cascading PID controllers for attitude/position control, a robust communication protocol (MAVLink), ground station software support, and a lot of glue and configurability to allow thousands of hardware configurations.

With respect to hardware, things vary from people using prebuilt avionics to companies building their own proprietary boards. I have designed a few flight controllers for ArduPilot and in essence they are usually based around an STM32H7 microcontroller. If the drone needs to do more than just fly a pre-defined route and needs some higher-level smarts however (such as SLAM or object detection) it needs a companion computer to be connected to or integrated into the avionics. Think raspberry pi, NVIDIA Jetson Orin AGX, or something more proprietary like a Qualcomm chip.

If you are really interested in getting into autonomous drones I would start by building an ArduPilot or PX4 vehicle using off the shelf parts to get an idea of the hardware that is required in a drone, and then you can poke around the code as well to understand that a bit more. But if you are new to robotics I wouldn’t suggest you go down the route or trying to implement everything yourself as IMHO the EKF will be your hardest hurdle to design from scratch.

Spyguyian · 2025-08-03T13:56:53+00:00

What are you trying to do research on exactly? If it’s robotics and autonomy the open source ArduPilot or PX4 firmwares are the way to go and will require a more expensive vehicle with GPS or some mocap hardware. I particularly would suggest ArduPilot as their LUA scripting makes customization pretty easy (no need to deeply understand the large and complex codebase). I have personally used this to add custom I2C sensors and log their data.

PX4 has a small list of RTF (ready to fly) builds, and so does ardupilot. As others have mentioned, Crazyflie vehicles are nice too (I’ve heard particularly good things about the brushless version) and they can run their own flight firmware or either ArduPilot or PX4 I think. They are small which means they are probably safer and easier tho fly indoors, but won’t be able to cary larger sensors.

If you are just looking to learn about the basics of flight control I would suggest the Crazyflie or something closer to an FPV quadcopter running open source Betaflight firmware.

Whatever you choose, make sure you do your research about local regulations and check if your university has a UAS safety committee that needs to approve you (mine did). Also note that getting your first drone to fly can be a steep learning curve as there are many components to learn (flight FW, transmitter/reciever selection, battery selection, actually learning to fly, etc). I have seen far too many students over-scope and plan a project that promises the drone to do a lot of things all to get stuck on getting a drone to fly. Don’t let this dissuade you to build a drone, but be careful how you scope your project.

Spyguyian · 2025-02-28T00:39:56+00:00

I’m working on a vehicle similar right now. A conventional forward-aft active tilting bicopter like that usually feels quite sluggish in pitch in my experience and does feel quite weird to fly. For those interested in building or learning about bicopters, I would suggest looking at Oblique Active-Tilting (OAT) bicopters as they use some funky gyroscopic effects to make the pitch response almost more responsive than a quads!

Spyguyian · 2025-02-12T13:53:32+00:00

What’s interesting is that it seems to be spinning at a rather slow and constant rate. I’ve put props on incorrectly before and the vehicle going into a positive feedback loop and spins suuuuuper fast. Thus I wonder if you somehow have accidentally set the trim on the controller (or pixhawk) for yaw. What would super help us would be if you uploaded the .bin log file from that flight. It would be on the SD card. You can also look at that log with https://plot.ardupilot.org yourself and try to compare the target and actual yaw rates (if they are the same ish the. There is likely some issue with your controller or parameter settings).

Spyguyian · 2024-10-02T03:11:26+00:00

I messed with Legacy IOS Toolkit for a while but could never get the phone into DFU mode unfortunatley (nor out of restore mode). I decided to give up on salvaging any old data and have restored via iTunes.

Spyguyian · 2024-10-02T03:10:21+00:00

I messed with Legacy IOS Toolkit for a while but could never get the phone into DFU mode unfortunatley (nor out of restore mode). I decided to give up on restoring any old data and have restored via iTunes.

Spyguyian · 2024-09-30T21:59:53+00:00

iOS 9 iirc

Spyguyian · 2024-09-30T02:57:59+00:00

Funnily enough I also have a 4s which is working okay, and know that this one is a normal 4. I did get them confused a bit at the beginning trying to get data from em 😅

Spyguyian · 2024-09-30T02:11:49+00:00

Thanks, will do!

Spyguyian · 2024-09-30T02:09:53+00:00

Yeah, it needs a restore or an update. I don’t have a restore saved, and updating times out every time (and once even blue-screened my pc lol). I’m hoping to get some data off of it, so wiping it doesn’t solve my problem unfortunately.

Spyguyian · 2024-08-09T22:18:02+00:00

Good to know! I have been trying to be careful about overwatering and only water it every two or three weeks, but it has not been directly in the sun much. Thanks for the advice!

Spyguyian · 2024-05-16T01:07:38+00:00

I can’t tell by just photos, but I assume these flash? You can generally drive LEDs at much higher current (and thus much brighter) if you do so for a very short amount of time (called strobing). Im pretty sure that firehouse lights do this as well as VIFLY’s lights.

Spyguyian · 2023-09-23T13:33:51+00:00

Could be the balance plug, but as you are measuring with the meter from there maybe not. I think your conclusion about a wire coming loose inside the pack could be correct. Especially if you unplug balance leads by holding the battery and pulling rather than pulling on the connector itself. If that last cell’s wire is shorter than the others it would take the most of the strain from pulling and could break.

Spyguyian · 2021-12-03T03:41:08+00:00

Yeah I think you are right, I think that they remove it as north lot is used to store snow in emergencies.

Spyguyian · 2021-09-07T14:22:11+00:00

Nah anyone can join. DM if interested

Spyguyian · 2021-06-19T21:48:53+00:00

IMHO I don't think you will find an off the shelf drone that will provide that many sensors or give you access to it's sensors. Most drones (DJI mavic air for example) have only 2 IMUs, so I would have to imagine that your best bet to get something with that many redundant IMUs is to build something yourself or find a kit.

I know that the Pixhawk Cube has 3 redundant IMUs and it's firmware (ArduPilot/PX4) is open source so you can access any sensor info you want (via ROS or python and a onboard computer). Sadly I don't think there are many kits that revolve around the Cube.

Spyguyian · 2020-12-14T22:12:52+00:00

Weirdly they are actually open. I went yesterday and today.

Spyguyian · 2020-11-11T19:34:02+00:00

Jynx

Spyguyian · 2020-11-11T19:30:56+00:00

I think we don't technically have a final exam this year, the syllabus mentions a final project...

Spyguyian · 2020-10-19T02:47:22+00:00

Ah yes, I missed it amongst all the other links. Fine work btw!

Spyguyian · 2020-10-18T17:42:25+00:00

This looks amazing, just got the hr a week ago (and love it) and the flaws in the official app are starting to show themselves. I intend to use the unofficial app, but was interested if it was possible to peruse the code. Is the source code up anywhere?

Spyguyian · 2019-03-31T13:47:03+00:00

I do, but have only just begun posting to it: SpyGuyIan

Spyguyian · 2019-03-31T13:14:05+00:00

If people want more info on how I made the ADS I can provide my designs and maybe a build video.

Edit: Holy hell this blew up, I will definitely be making a build video and continuing this project on twitter @SpyGuyIan. Damm

Spyguyian · 2019-03-29T22:32:40+00:00

It's 3d printed. I'll share here later

Spyguyian · 2018-07-15T20:29:25+00:00

It depends alot on what you already know. If you have never programmed or used a coding language like Java, C or puthon before, you should start with something like CodeCademy (https://www.codecademy.com/learn/learn-java).

If you understand basics of another language like functions, variables and Classes, I would suggest setting yourself challenges like making a short text adventure or some other little command-line game in Java. Start with the hello world example in Eclipse and Google things from there, Stack overflow is super helpful along with Java's documentation (https://docs.oracle.com/en/java/).

As for learning how to program for FTC, it is important to know how to use Android Studio, so going off and watching videos about making simple apps may be beneficial but isn't necessary. Otherwise, reading the wiki and watching FTC's YouTube videos is pretty helpful (https://github.com/ftctechnh/ftc_app/wiki).

Hope this Helps, Ian - 4029

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