multitask drone

Projects General Guidance
1

hi, new to arduino -

i have extensive audio dsp and reasonable 3d coding experience and would like to build a drone. i've done a small amount of building ages ago so it seems a reasonable project given the amount of hobbyist resources today.

initial research suggests that the cost and complexity isn't as extensive as thought. there are arduino drone tutorials everywhere, and arduino seems to be the popular choice for this task. i would like to combine several functions in one build, so now is the time to seek informed advice, and i can casually run this as a side project while i work on other things.

the drone needs to transmit video (ideally to a laptop - i have no knowledge of RC). the primary function is security and visible deterrence. i'm sure i can buy this functionality in kit form already. but IR camera would be a strong plus.

the secondary function is for sound - this may be difficult to relate to for non-audio devs.. i don't know what kind of speaker/transducer, even a physical/mechanical mechanism like a whistle or similar (which would have a motor to modulate the tone). i enjoy AI coding and easily imagine building half a dozen autonomous drones for interactive/aleatoric musical performance.

i have read that combining a raspberry pi with an arduino is prudent for drones that perform more complex tasks - the "programmable processor mileu" is entirely new to me, i don't know, but i prefer to keep things as simple as possible. the idea of RC control to two processors daunts me. ....i'm somewhat of a masochist when we come to audio synthesis coding and respond well to low cpu overhead.. ..so if i can squeeze drone navigation, camera and some rudimentary sound synthesis into one brain i'd be pretty happy about it.

i should also say that some two-way sound would be a plus. if i can send instructions from a laptop (as said - this is all NEW to me) ..transmitting voice to and from would be real fancy but receiving some complexity of commands to generate specific sounds would suffice as well.

i don't mind if this takes several months, it seems like DIY arduino based drone isn't that complex. i'm good with diy - i'll be building my own frame despite the asshats that say "they don't work, you should buy one from us.." seen too many ppl build ones that work to believe them.

i also don't like spending money - i'd rather get kit i can add to and modify than things i'll discard when improving my design. this is a hobby for my time, not my wallet. right now i'm seeing project costs as under $100 for an arduino based quadcopter.

ultimately, it will mainly be used for chasing noisy birds out of some trees, so eg. i'll want it to fly around for a minute, then park in an alcove, then swoop out when they get noisy again, so long battery life is a good trait, but only for periodic use over a small area. when (haha) i get the AI hammered out it ought to be able to find its own charging station. i enjoy AI coding, and anticipate continuing to push drone builds into (aurally) interactive entity platforms.

please advise on processor, battery, motor investment choices (or where to look to inform myself) without all the asinine "only buy our products/kit" crap that's all over our terribly self debilitating society nowadays. ty :slight_smile:

2

How will a microphone, mounted on a noisy drone, be able to hear birds?

But, if you ever get this working, you could sell it to airports to keep birds away from jet intakes.

3

jremington:
How will a microphone, mounted on a noisy drone, be able to hear birds?

Directional mic?

4

Not at all asinine! When you have built one and have it working you will have a much better idea of what your personalized drone will be.

Paul

5

I've a decent amount of RC experience (I've been designing and building Arduino RC fixed wing planes for more than a year now) and can give some pointers.

1.) Power - You will need 4 motors with props that are correctly sized AND balanced. Each motor needs an ESC (electronic speed controller). The ESCs need to have a rated current exceeding that of the motors (given my the motor manufacturer). Each ESC will most likely have what is called a BEC, which is a regulated voltage supply up to somewhere around 5V at 4A. The ESCs control how fast the rotors spin based on a PCM signal send by the flight controller. This signal is usually the same type as signals for analog servos, so you can treat the ESCs exactly as you would a servo. For instance ESC.write(0) would mean the props don't spin, and ESC.write(180) means props at full throttle. NOTE: the ESCs must first be calibrated (usually via throttle calibration - intrusctions should be provided in ESC user manual). The battery/batteries need to connect to the ESCs through either direct connection or a power management board.

2.) Batteries - If using one battery, you might want to go for a 3 cell (3S) battery with a capacity of anywhere between 2,000-3,000mAH (milli amp hour). This is your capacity rating. Total battery life in minutes is (mAH * 1,000 * 60)/(max current draw). The "C" rating of a battery gives an idea of max peak discharge. For instance, a 2,000mAH battery with a 20C rating has a max current discharge of 20A (peak). Also, the more cells, the higher the voltage output. He required number of cells will depend on your motor (will be specified by the motor manufacturer). Also, you'll probably want to use LiPo batteries. These batteries need to be kept from heat and direct sunlight and NEED to be balanced when charged. Do yourself a favor and don't skimp out when buying a LiPo battery charger.

3.) EMI - Always use twisted pair wiring for signals and power cables. Shielding is a plus if you can swing it.

4.) Processing - Raspberry Pi and Arduino together is by no means impossible and I would suggest doing this. Arduino for control and RPi for heavy DSP. Seeing how slow an Arduino is (unless you're using a Due), the RPi will be absolutely necessary for video and audio DSP. At the same time, don't be afraid of trying crazy and creative solutions. Tip: take a look at using an Android phone with a custom app to do the processing. Think about it: the phone already has a mic, camera, big processor, GPS, magnetometer, IMU, and more. Just sayin.

4.) Sensors - You will need an IMU (inertial measurement unit) for flight stabilization. This will provide orientation data and feedback to the flight controller. The IMU should have a 3 axis accellerometer, 3 axis gyroscope, and magnetometer. You might also want some sort of altitude sensor, but good LiDAR sensors don't come cheap, so you'll need to get creative.

5.) Control - You will need to use PID loops for controlling your drone. Google it if you are not already familiar with how to use and tune them. Also, you will need to filter the IMU dat with either a Kalman filter or a complementary filter. The IMU DSP can be done on the Arduino (and should be).

6.) Supplies - Hobbyking is a great place to buy RC stuff. For batteries, I like the ones from Turnigy. Can't speak much about the motors or ESCs, but is won't be hard for you to figure it out. As for he type of Arduino, I'd use a Mega or Due based on the number of serial ports on each (all other Arduinos have only 1 hardware serial port). These serial ports may prove quite useful when you try implementing more and more sensors. As for an IMU, I'd look at an MPU6050 or an MPU9250.

Any questions?

6

P_B ty for taking the time to provide a fingerhold. i just blew $ on antique noritake porcelain, i think further questions will follow when i can permit myself to spend licentiously once more. at that point, i'm sure i'll have more specific enquiries.

tbh as a relative old timer, i've never owned a wireless communications device of any sort, so thinking of eg. using an android is an option i'd only avail by reading. things to be gleaned by following choice discussions, time is commodity. appreciated.