Building a sub 250g Autonomous Drone with Ardupilot and ExpressLRS AirPort Telemetry
Summary
TLDRIn this video, the creator introduces their DIY autonomous drone project, showcasing a lightweight quadcopter weighing under 250g. The video highlights the build process, including choosing cost-effective parts like the Speb F405 mini stack and Darvin FPV motors, and crafting a custom frame. It also covers installation of ArduPilot software, configuration of components like GPS and ExpressLRS, and various flight modes. The drone won first place at a major Polish competition, and viewers are shown how to build their own entry-level ArduPilot drone step by step.
Takeaways
- ?Üdd The video showcases a DIY autonomous drone project that won first place in a major drone competition in Poland.
- ?Üd2 The drone is lightweight, weighing less than 250g, and utilizes Ardupilot software for autonomous flight.
- ?Üd5 The project features a custom frame made from carbon fiber for stiffness and durability, sponsored by PCBWay.
- 💵 The drone is equipped with advanced telemetry over Express LRS, enhancing its autonomous capabilities.
- 💲 The frame design process involved multiple iterations to achieve the right balance of lightness and strength.
- 💵 The build includes affordable components like Darvin FPV motors and is designed to be an accessible entry-level project.
- 💵 The video provides a step-by-step guide on assembling the drone, including motor installation and wiring.
- 💲 The flight controller is programmed with ArduPilot, and the video demonstrates how to flash the firmware correctly.
- 💵 The drone's maiden flight tests various modes like Stabilize, Alt Hold, and Loiter, showing good initial performance.
- 💲 The video introduces an innovative use of Express LRS for bidirectional telemetry, overcoming the limitations of traditional radio control.
- 💵 Additional features like geofencing, RTL, and autonomous mission planning are demonstrated to highlight the drone's capabilities.
Q & A
What is the purpose of the DIY drone project mentioned in the video?
-The DIY drone project aims to build an autonomous drone that weighs less than 250g, runs on Ardupilot software, and uses ExpressLRS for telemetry, making it an affordable and lightweight quadcopter for beginners.
What are some of the key hardware components used in the drone build?
-The key hardware components include the SpeedyBee F405 Mini Stack, Darvin FPV motors, a GPS unit, ExpressLRS receivers, and a custom carbon fiber frame.
Why did the creator use carbon fiber for the drone frame, and how was it manufactured?
-Carbon fiber was chosen for its superior strength and stiffness compared to plastic. The creator used a company called PCBWay to manufacture the frame through CNC machining, resulting in a flawless, lightweight, and durable part.
What was the issue with the screws that came with the Darvin FPV motors, and how was it resolved?
-The screws that came with the Darvin FPV motors were too short and thin for the custom carbon fiber frame. The creator solved this by pre-drilling the mounting holes and threading them for M2 screws.
How does the creator configure and install the Ardupilot software on the drone?
-The creator configures and installs Ardupilot by flashing the firmware onto the flight controller using the STM32 Cube Programmer. Before doing this, the creator ensures the motors spin correctly using BLHeli software.
What is ExpressLRS, and how does it enhance the drone’s performance?
-ExpressLRS is a low-latency radio control system that provides telemetry over a long range. In this project, it enables wireless USB-like connection to Mission Planner, allowing for real-time monitoring and adjustments during flight.
What is the significance of the drone weighing less than 250 grams?
-Weighing under 250 grams is important because it allows the drone to comply with regulations in many countries, enabling the user to fly it in most locations without requiring special permits or licenses.
How did the creator integrate a geofence into the drone's mission, and what happens if the drone crosses it?
-The creator set up a geofence to restrict the drone's movement within a designated area. If the drone crosses the geofence in Loiter mode, it will stop; in AltHold mode, it will trigger an automatic Return to Launch (RTL) function.
What is the ‘throw mode,’ and how was it used during the flight test?
-Throw mode allows the drone to be launched by physically throwing it into the air, after which it automatically transitions into its pre-programmed flight mode. The creator demonstrated this by throwing the drone to start its mission.
What are some of the flight modes demonstrated in the video, and how do they function?
-The flight modes demonstrated include Stabilize, AltHold (maintains altitude), Loiter (hovers in place using GPS), Circle (orbits around a point), and Guided (autonomously flies to a point selected on a map). These modes showcase the drone's versatility.
Outlines
🚁 Introduction to the DIY Autonomous Drone Project
The video begins with a playful introduction, showcasing a small drone and hinting at the purpose of the video—building a DIY autonomous drone. The drone weighs less than 250g, runs on powerful ArduPilot software, and features fully functional telemetry over ExpressLRS. The creator shares that this project won first place in a major Polish drone competition and promises a step-by-step guide on building the drone.
🛠️ Choosing the Right Hardware for the Drone Build
The focus shifts to selecting hardware components that are both lightweight and budget-friendly, ideal for an entry-level ArduPilot quadcopter. Key components include the SpeedyBee F405 Mini Stack and Darvin FPV motors. The creator discusses experimenting with different frame designs, materials, and printing techniques to find the right balance between durability and weight. Carbon fiber is chosen for the final frame, sourced from PCBWay, which specializes in custom parts.
🔧 Assembling the Drone: Motors, GPS, and Electronics
With all the parts in hand, the next step is assembling the drone. The creator faces challenges with motor screws, which are too short, and resolves this by pre-drilling and threading for M2 screws. The GPS unit and ExpressLRS receiver are attached with double-sided tape, while the ESC and flight controller are installed using included hardware. Soldering work begins on the motor wires and XT30 connectors, preparing the drone for its next stage.
📡 Configuring the Software: ESC and ArduPilot Setup
Attention turns to setting up the software, starting with configuring the ESC settings using BLHeli software before installing ArduPilot. After ensuring motor spin directions are correct, the flight controller firmware is updated with STM32 Cube Programmer. Post-installation, the creator connects the components (ExpressLRS, GPS, Compass) and secures them. The weight of the drone, including a custom-built battery, remains under 250g, making it compliant with lightweight drone regulations.
📻 Setting Up ExpressLRS Radio Control and Calibrations
The ExpressLRS radio system is configured using the ExpressLRS Configurator app. Firmware is built for the transmitter and receiver, ensuring synchronization through Wi-Fi. After the ExpressLRS setup, the drone's frame type is configured in ArduPilot, and the accelerometer and compass are calibrated for stability. Further parameters, like GPS setup and radio input calibration, are adjusted. The creator also explains how to assign switches for different flight modes and arming the drone.
🚁 Flight Testing and Troubleshooting with ArduPilot
The drone is tested for the first time in various flight modes. Stabilize and AltHold modes work well, but Loiter initially struggles until the GPS gets a proper satellite fix. The creator demonstrates the drone's ability to autonomously land using Land mode. To enhance telemetry capabilities, the creator configures the drone for full Mavlink telemetry over ExpressLRS, avoiding the need for heavier radio modules.
📶 Enhancing Telemetry with ExpressLRS AirPort Feature
The video introduces the ExpressLRS AirPort feature, which allows the drone's receiver and transmitter to act as a bi-directional serial data link, essentially creating a wireless USB connection for real-time telemetry. The setup process is explained step-by-step, including changing ArduPilot parameters to enable Mavlink over ExpressLRS. The creator demonstrates how to connect a mobile device to the transmitter for in-flight telemetry and control.
🕹️ Controlling the Drone and Adding New Hardware
The creator addresses the challenge of controlling the drone while using ExpressLRS for telemetry by adding a second pair of modules at a different frequency to avoid interference. New hardware, including a 3D-printed frame cover, an RGB strip for visual feedback, and a camera mount for first-person flight recordings, is also added to the drone.
🌐 Setting Up Missions and Using Throw Mode for Launch
The creator demonstrates how to plan a mission in ArduPilot, using geofencing and waypoints for autonomous flight. A unique feature, 'throw mode,' allows the drone to be launched into the air manually and immediately begin its mission. After setting up the parameters and testing the throw mode, the drone successfully completes the mission.
🏞️ Testing Geofence, Circle Mode, and Autonomous Features
Further testing is done to demonstrate the geofencing feature, which prevents the drone from leaving a predefined area. The creator tests flight modes like 'Circle,' which orbits the drone around a target, and 'Guided,' where the drone autonomously flies to a selected point on a map. The drone’s smart RTL (Return-to-Launch) feature is also tested, showing its ability to return to its starting position.
🎥 Advanced Flight Modes and Guided Telemetry
The guided mode, made possible through Mavlink telemetry, allows the drone to fly to any point selected on a map via Mission Planner. The creator walks through using this mode for precision tasks like video recording or inspections. They demonstrate how the drone moves autonomously between points on the map, showcasing the flexibility and usefulness of Mavlink telemetry.
✨ Conclusion: Drone Project Success and Future Plans
The creator concludes the video by reflecting on the success of the project, emphasizing the benefits of having a sub-250g drone for legal and safe flying. They express excitement about the future of lightweight drones, hinting at potential upgrades such as gimbals and further ExpressLRS developments. Additional thoughts and project details are shared, with the creator inviting viewers to check out future content and support via Patreon.
Mindmap
Keywords
💡Autonomous drone
💡ArduPilot
💡ExpressLRS
💡MavLink Telemetry
💡Geofence
💡Carbon fiber
💡Mission Planner
💡ESC (Electronic Speed Controller)
💡Flight modes
💡Waypoint navigation
Highlights
Introduction of the DIY autonomous drone project and its successful participation in Poland’s biggest drone competition, winning first place.
Drone weighs less than 250g, runs on ArduPilot software, and features full telemetry through ExpressLRS.
The project aims to make an affordable, lightweight entry-level ArduPilot quadcopter using the SpeedyBee F405 mini stack and Darvin FPV motors.
Challenges in designing the frame, leading to multiple design iterations with materials like PTG, PLA, and carbon fiber nylon.
The frame design was finalized using CNC-machined pure carbon fiber from PCBWay, providing an excellent combination of lightness and durability.
Detailed assembly process, including motor installation, ESC soldering, GPS, and ExpressLRS receiver mounting.
Step-by-step instructions for installing and configuring ArduPilot on the flight controller using STM32 Cube Programmer.
Explanation of motor spin direction calibration using BLHeli software to ensure correct operation before flying.
ExpressLRS setup guide, including firmware configuration for radio control and telemetry using Wi-Fi flashing.
ArduPilot parameter tuning for optimal performance, including accelerometer and compass calibration.
Exploring various flight modes such as Stabilize, AltHold, Loiter, and Land Mode, with real-world testing.
Successful demonstration of geofence feature, preventing the drone from crossing boundaries and activating Return-to-Launch (RTL) if crossed in certain modes.
Circle mode, Flip mode, and Guided mode are tested, highlighting their practical and fun applications for autonomous drone control.
MAVLink telemetry via ExpressLRS AirPort feature, creating a wireless USB link for live telemetry data and real-time parameter adjustments.
The drone's versatility as a sub-250g flying machine allows it to operate legally in more locations, making it ideal for learning, testing autonomy, and enjoying drone flight.
Transcripts
oh hi everyone didn't see you there
you're probably wondering what I'm
trying to do with this tiny drone and
the answer is very simple I'm going to
throw it
[Music]
away oh look and he also came back okay
so what you just saw in the silly intro
is my new DIY autonomous drone project
in action this tiny thing weighs less
than 250 g it runs on powerful alop
pilot software and it even has fully
functional maving Telemetry over Express
lrs and besides that I recently took
this project to the biggest drone
competition in Poland and guess what it
won the first place so now in this video
I'm going to show you step by step how I
build it and how you can build it too
seems interesting if yes keep watching
and let's get
started all right so first we have to
choose some Hardware I want this drone
to be not only light but also easy on
the wallet so that it can be a great
entry level ardupilot quadcopter for
everyone and that's why the main star of
this build is the speb f405 mini stack
and to go along with it I got four small
Darvin fpv Motors they are like six
bucks per motor which is a pretty good
deal if you ask me we also have GPS
units Express lrs receivers batteries
and some other stuff that we'll talk
about later in the video but for now we
have to focus on the most important part
which is the frame I wanted to make it
myself to keep it light and also to have
enough room for future upgrades
something I thought would be a
straightforward process actually took me
a few different designs until I got
right at first the frames I designed and
printed from ptg were way too big and
thus too heavy they also used MRE screws
which in the sub 250 g category is a big
no no next I tried with smaller 160 mm
frame but the ptg one turned out to be a
bit too flexible pla too brittle and
laser cut plywood was the lightest I
give it that but the flex on that thing
was way too big
the one filament I tested and actually
got great results with is carbon fiber
nylon which I printed using my
University science team bambula printers
frames printed from this material are
surprisingly light but also really
durable but to be honest no plastic can
even match the wonders of pure carbon
fiber and luckily I know a company that
specializes in making such Parts pcbway
which is the sponsor of today's video
has a great service for making custom
pcbs in all shapes and sizes but did you
know that they can also 3D print or even
better CNC machine Any Part you want and
they have wide range of materials too
you can choose aluminium for lightness
stainless steel for strength or carbon
fiber for both so to get the frame I
uploaded a flat version of my design to
the pcda website and submitted a
request then after waiting just a few
days I received my package and now take
a look at this beauty it's clean it's
shiny the dimensions are correct and the
whole part is just
Flawless now when set side to side with
a plastic counterpart the carbon is a
few grams heavier but the difference in
stiffness is just night and day so I'm
definitely using it for this drone and
now if you also have a project that
could use some carbon fiber don't wait
and go check out pcba website at
pcb.com and we are back to the video
now is the time to put all the parts
together first we got to screw in all
the motors but the problem with those
Darin fpv 114s is that the screws they
came with are very thin and just too
short to work with our frame so what I
did is I pre-drilled the mounting holes
and then threaded it for M2 screws it's
a delicate process but it can be done
and you only need two screws for each
motor next thing to do is attach the GPS
in the front which I did by using double
sided phone tape and on the back I taped
the express lrs receiver
antenna after that I placed the ESC on
four long M2 screws and started
soldering all the motor
wires following that I soldered the xd30
connector at the back along with
included capacitor to smooth out the
voltage
spikes now it's a good moment to add our
flight controller so I stacked it on top
of the ASC and connected them both with
the wires that came in the Box
normally I would now proceed with
installation of ardu pilot but while
making this video I found out a bug that
prevents you from changing ESC settings
if you do have it installed so if you
just bought a fresh flight controller
with default beta flight installed
connect to it and check every motor spin
Direction
if it's wrong then you can use BL hel
software to reprogram ESC with the
correct
one once you make sure it's all good we
can download the hex file from the AR
pilot website and then open stm32 Cube
programmer remember to get the Drone
into the dfu mode by pressing the side
button make sure your PC recognizes it
as STM 32b loader and if it's it does
you can simply press connect open the
hex file and click
download and after a while just like
that we got the fresh arop pilot install
running on our speb flight controller
Mission planner up shows it works great
so now let's solder remaining components
and start the configuration process here
I only needed to solder Express LS
receiver wires as well as both GPS and
Compass to the right ports and of course
all the connection diagrams will be
there in the
description now after securing the stack
with self-locking nuts and adding a
velcro strap the whole drone weits just
about 73 G not bad and by strapping my
homemade frees lithium battery the
weight increases to 216 G which means we
are still way below
250 now the last thing we have to do
before jumping to arop Pilot is setting
up Express lrs radio control to do this
we use Express L configurator app in
which you can build firmware for your
chosen transmitter and receiver
important thing is to pick a release
version greater than 3.3 and also to
choose the Wi-Fi flashing
method by doing so the app will generate
you two files that you need to transfer
to your mobile
device then by waiting 60 seconds or by
manually switching the Wi-Fi on you can
connect to others devices by choosing
them on your phone you will be then
transported to the page where you can
simply upload the files generated
before and that's all if everything is
right and you set the same password on
both devices you will get a connected
message on your transmitter and solid
light on the receiver it means that both
modules are now linked and we can
proceed to our the pilot stuff
all right first let's make sure that the
frame type is set to X and that the HRS
orientation parameter is set to zero
because our flight controller is facing
forward next in the initial tune
parameter tab we are going to set it up
for 3in propellers and 3s lay on battery
pack after that we have to perform
accelerometer calibration by placing the
drone on each
axis second thing we need to calibrate
is the compass and it's basically just
about rotating the drone on each axis
until the green bar reaches the end best
results can be achieved by doing it
outside far from magnetic
interference when the calibration has
finished we need to reboot the flight
controller and set up the GPS serial
Port if it's set up right we'll see no
GPS status change to no
fix next there are a few parameters that
have to be set in order to make Express
lrs work with arop pilot all of them
will be listed in the description and
after changing them we should see our
radio input in the radio calibration
tab now we simply have to move all the
sticks switches and potentiometers to
let arop pilot know their Max mean and
middle position
and after it's done I recommend setting
one of your fre position switches to
flight mode Channel and then pick
stabilize alt hold and loiter for the
first time
flight make sure it works and if yes we
can proceed further
you also need to assign one two position
switch for arming the quad and if you
have more you can set additional one for
landing don't forget about fail safe tab
which tells the autopilot what to do if
the battery is low or the transmitter
signal is
lost now we are almost at the Finish
Line the last thing to do is tell the
flight controller which pwm Channel
controls which motor in the servo output
tab you can then check if your settings
are correct in the motor test toop motor
a should be front right motor B the rear
right C the rear left and D the front
left
and if your Motors rotate at different
speeds it's good idea to perform ESC
calibration for my ESC I set up dshot
300 and it seems to work pretty
fine last thing to do is attach the
propellers here I went with 3in triple
blade props to make the first flight
more stable but for efficiency we'll
definitely want to swap them for two
bladed
ones finally check is to see if each one
of them generates downwards
thrust and if they do we can strap the
battery and go test this baby out
[Applause]
[Music]
stabilize and Al hold modes were working
pretty well out of the box but loer
initially was quite
[Music]
unstable however once the GPS acquired
more satellites the Drone was able to
firmly stay in place
[Music]
all right so now we are in loer mode and
let's let's lift it up a
bit and at the end of the flight I also
tried the land mode which without
surprises successfully descended our
quad to the
ground so it's pretty high right now and
now let's turn the land
mode so we are now Landing
[Music]
and we
landed okay so our drone flies and
that's great but to take full advantage
of many autopilot features we need a
Telemetry many air ceilings such as mine
have limited Telemetry options where
they can for example display battery
status on your radio but to achieve full
Ming Telemetry which is basically
wireless USB connection to Mission
planner you need to use one of those big
heavy and usually pricey radio modules
and that's just not going to cut it on
our drone but what if I told you there
is another way you see for the past few
months I was testing a new Express AES
feature called airport and what it does
is transform your receiver and
transmitter into bidirectional
transparent serial data link which as I
said before is like wireless USB so
let's set it up the entire process is
quite simple first you got to connect to
your T and ERX just like when updating
the
firmware then you need to check the used
airport box and set the same U Bo on
both modules
next we need to change arop pilot serial
port settings so we locate the
parameters for our receiver and change
its protocol from airc to mavlink and
also change the B rate to the one that
airport is currently using now you can
connect the lrs transmitter to your
mobile device via
USB but make sure the backside switches
are all set in the flashing position or
it won't work in Mission planner choose
the USB device and the same bow
rate click connect and if it start
downloading the parameters the Telemetry
is up and
running and as you can see we have all
the sensors live data on the left and we
can also calibrate or change any
parameter on the go and that's really
handy however you might notice a tiny
little problem now if our air ceiling is
used as Telemetry how do we actually
control the Drone and well there are
solutions you can for example hook up a
game pad to the mission planner and
control the Drone with it I did it once
and it was fine but it's far from ideal
so instead I simply bought another pair
of Express lrs modules but this time the
868 MHz version to avoid any
interference I soldered the new receiver
to the U number three and taped it to
the bottom of the frame then I
configured it the same way as we set up
the old air ceiling
before and while we are at adding things
I also designed a 3D printed stack cover
to which I taped a 5vt RGB strip it will
make the quad more visible but it can
also inform you if the Drone is armed or
Not by changing the color and on top of
that I added am mount for rankam camera
to record all the flights from the Drone
perspective now when put all together
the quad looks like this
I also designed a special fre printed
mounts that attach to the back of my
radio and hold both Express lrs modules
together with a 10-in tablet for running
Mission
planner loading up the parameters takes
about 30 seconds which is not bad and
after that we can for example go to the
radio Tab and see that both rirc control
as well as Telemetry works as intended
we can also change flight modes straight
from the mission planner or do it as
usual using radio
switches but one of the most useful
things is actually checking and
modifying the mission in the plant
TB speaking about the mission here is
the plan first I drove a geofence around
an empty field which should keep the
Drone contained in that
area next I created a set of way points
which the quad should follow at about 40
m altit VI then at the end of the
mission the Drone will come back to the
starting point and perform a landing to
make it more interesting our quad will
start the mission with the same trick
from the intro which is of course
throwing to make it work we have to set
two parameters throw next mode to Auto
and throw type to zero now once we have
it all set up we can write both
parameters ad mission to the U pilot and
give it a test
so now we are going to start the mission
using the throw mode so what we have to
do is first of all set the throw
mode as you can see right here
probably it's set to throw and now we
can check our
arming and it's not arming why GPS
glitching two very boring minutes
later all right so now it's red so it's
armed and uh let's just start
recording the camera is
recording so let's throw it out after I
throw it it should instantly go to the
auto mode and start doing the mission
all by itself so let's see if it works
I'm going to get
here and one two 3 Let's Go
one two three let's
go and it went
[Music]
n
n
I don't deny there's some strange
evolutionary process going on but
mankind won't be
destroyed the fact that you and I are
working here
today evidence that
[Music]
[Music]
and it came back granted I think I lost
a signal for a while with the Telemetry
but it still did its mission right so
the flight went quite well and the Geo
fense hasn't been bridged once but I
also wanted to know what would happen if
we crossed the line
[Music]
so in lighter mode it just won't allow
the quad to pass defense but if you
switch to Al hold and now do it
again the Drone will go there and
activate RTL by
itself so it climbs up and it's going to
come
back so setting up a geofence is a good
way to ensure safety if you are flying
in tight spaces or if you are just
learning how to fly and don't want to
lose your quad at the end of the flight
I also tried a fun flight mode called
Circle which does exactly what it sounds
like by getting the Drone high and
stabilizing the footage in gof flow I
could get a pretty good look at my
neighborhood next day I went to the park
from the intro to do some more flying
here I used the circle mode to orbit
around myself and it worked fairly
[Music]
[Music]
well another fun flight mode is the one
called flip when when you put your drone
in Al hold and then switch to flip mode
the Drone will do the trick all by
itself pretty
cool and the last thing I wanted to show
you is the guided mode this mode can
only work with Ming Telemetry which is
something we have on board by using this
mode we can simply Point anywhere on the
map and our drone will fly there by
itself quite useful if you are doing
some kind of inspection or video
recording or if you are too lazy to
touch the
controller okay so now we are on the
data Tab and as you can see the Drone is
currently in this single position it's
not moving because it's in loer and uh
because we have the full maving
Telemetry we can just tap anywhere on
the screen for example
here and we can give it a command to fly
there oh wait wait wait a
moment here let's say fly to here we
have the altitude 40 m and let's
go and now we have our Waypoint and the
Drone all by itself flies to that
Waypoint and it's back there and now we
can try and get it back to
us let's just switch out to pan off
let's get it here fly to
here and it's coming
back as you can see on the tempet screen
and it's currently hovering above us and
we can just enter for example
RTL uh right
here and it will descend all the way
down to the point where it started so
probably somewhere around
here that's the power of smart RTL
pretty cool right all right so that's
all for this video I'm really happy with
how this drone has turned out having a
quad that is soup 250 g allows you to
fly safely in most places without
breaking a law so it's a perfect machine
to learn how to fly to test some
autonomy stuff on and also to just have
fun drone components are getting smaller
and lighter every year recently for
example kadak released some ultra light
fpv gimbals so who knows maybe for part
two I will try to make a mavic mini
killer out of this drone I even tested
it with my walks nail once and it is
promising also Express ERS developers
are constantly cooking new exciting
updates so Telemetry will probably be
much better in the future if you are
interested I have some additional tips
and thoughts about this project but I'm
just too lazy to add them to this video
so you can check description or my
patreon page for more by the way I will
also try to upload there some footage
from the Drone competition
because it's pretty crazy what we did
there it will be public of course but
you can also support me if you enjoy my
work also after this competition I have
like four of these drones so I'm
thinking about testing some cool artop
pilot stuff like following or swarming
would you like to see a video about that
if yes leave me a comment and share your
thoughts about this project but for now
I'm out thank you all for watching
thanks pcba for sponsoring this video
congratulations on 10 anniversary by the
way and we'll see you all soon bye
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