With the ground plane attached: 178 METERS!
More than 3x the range in this test, just from adding those wire arms.
This suggests an insufficient ground plane was limiting my antenna setup. Excited to try it on the drone next!
More than 3x the range in this test, just from adding those wire arms.
This suggests an insufficient ground plane was limiting my antenna setup. Excited to try it on the drone next!
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First, without the ground plane: packets stopped arriving at about 58 meters.
Link made this easy to check on foot. No need to fly the drone just to find out where reception drops off!
Then back to the transmitter to add the wire...
Link made this easy to check on foot. No need to fly the drone just to find out where reception drops off!
Then back to the transmitter to add the wire...
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For the test, I added the ground plane to the TRANSMITTER antenna, not Link.
The transmitter stayed in place while I walked away with Link, my handheld radio monitor, watching for incoming packets.
One walk without the wire, then one with it.
The transmitter stayed in place while I walked away with Link, my handheld radio monitor, watching for incoming packets.
One walk without the wire, then one with it.
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I made a simple ground plane: two wire arms, each extending 17.3cm from the center. That's a quarter wavelength at 433.8MHz.
It contacts the antenna connector's ground. Shown here on Link to illustrate how it attaches, not how I tested it.
2/5
It contacts the antenna connector's ground. Shown here on Link to illustrate how it attaches, not how I tested it.
2/5
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About $0.02 of wire tripled the range in today's Centauri radio test!
I'd been puzzled by the limited range of my homebuilt drone's radio link. Turns out the antenna's ground plane deserved a closer look.
Here's what I tried!
I'd been puzzled by the limited range of my homebuilt drone's radio link. Turns out the antenna's ground plane deserved a closer look.
Here's what I tried!
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Centauri with the new 2,200 mAh battery!
Down from the 3,300 mAh one I was using.
It flies like a CHAMP!
💪
Down from the 3,300 mAh one I was using.
It flies like a CHAMP!
💪
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If you've written Python but never sent a command over radio, this is a fun place to start exploring! 🙂
Transmitter hardware and code: github.com/TimHanewich/ce…
#FullStackFlight
Transmitter hardware and code: github.com/TimHanewich/ce…
#FullStackFlight
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The radio conversation goes both ways. Centauri can send telemetry back, and the transmitter's dashboard displays pre-flight information.
You can also update flight-controller tuning settings wirelessly, without plugging a cable into the drone.
4/5
You can also update flight-controller tuning settings wirelessly, without plugging a cable into the drone.
4/5
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How does that message leave the laptop?
A USB-connected Raspberry Pi Pico and HC-12 radio module bridge the gap. The Pico passes the data to the radio, which sends it wirelessly to the aircraft.
3/5
A USB-connected Raspberry Pi Pico and HC-12 radio module bridge the gap. The Pico passes the data to the radio, which sends it wirelessly to the aircraft.
3/5
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Move a stick, and a Python program on the laptop reads the input. It packs your throttle, pitch, roll, and yaw commands into a message for the drone.
You can follow that translation in the source code, from joystick movement to the bytes being sent.
2/5
You can follow that translation in the source code, from joystick movement to the bytes being sent.
2/5
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An Xbox controller, a laptop, and a radio. That's how you pilot Centauri!
Centauri is our open-source quadcopter ecosystem for learning how drones work. Over four weeks, we'll introduce its four main components.
First up: the transmitter.
🧵 1/5
Centauri is our open-source quadcopter ecosystem for learning how drones work. Over four weeks, we'll introduce its four main components.
First up: the transmitter.
🧵 1/5
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#3 = auto discovery and selection of USB connections used for the transceiver platform connection.
No longer a need to manually enter in the device path! 🥳
No longer a need to manually enter in the device path! 🥳
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#2 = CPU benchmark at boot. This is just a quick verification to confirm the PC you are using is quick enough to support the 20 Hz transmission rate for safe control of the drone.
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Some updates for the Transmitter program are now live!
#1 = State of Charge estimator, which is then used to estimate the flight time remaining.
🧵
#1 = State of Charge estimator, which is then used to estimate the flight time remaining.
🧵
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Centauri quadcopter v2 is now live!
GitHub repo fully up to date with the newest version, PCB tested and available for sale, and 3D-printed parts library updated!
github.com/TimHanewich/ce…
GitHub repo fully up to date with the newest version, PCB tested and available for sale, and 3D-printed parts library updated!
github.com/TimHanewich/ce…
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