So how does radio communication work, and what are some things to be aware of? I want to make a drone, so I will need to be able to communicate with it remotely, even when it is thousands of feet away. How much power is needed to send such a signal? Also, what is the limiting factor in terms of speed?

 

A UAV (Unmanned Aerial Vehicle) or as we like to call it a drone is not something you easily put together, even a small simple one is a complex affair. Most of the common in use drones use either 2.4 GHZ or 5.0 GHZ transceivers with multiple channels and actually normally have an on board OS (Operating System) like for example an Android OS. Most of the better ones have a range of about 4 miles and are good for maybe 20 to 30 min flight time. They are also sending back video in addition to other data. They also know where they are and where they too off from which is used for failsafe so when their battery gets low they automatically come home.

I suggest you start with drone radio control systems because you are not about to build this type of radio in your basement on a bench. Figure out how many channel;s you want, how much weight you plan to lift and a few dozen variables before you even think about communications.

Sometimes even a $32,000 drone can have a real bad day. Drone used in turnpike bridge inspection crashes into water, that had to be a bad day. Following the demonstration the state decided to postpone buying any.

Before I forget, the maximum effective range comes down to things like power, obstacles and frequencies used.

Ron

 

A UAV (Unmanned Aerial Vehicle) or as we like to call it a drone is not something you easily put together, even a small simple one is a complex affair. Most of the common in use drones use either 2.4 GHZ or 5.0 GHZ transceivers with multiple channels and actually normally have an on board OS (Operating System) like for example an Android OS. Most of the better ones have a range of about 4 miles and are good for maybe 20 to 30 min flight time. They are also sending back video in addition to other data. They also know where they are and where they too off from which is used for failsafe so when their battery gets low they automatically come home.

I suggest you start with drone radio control systems because you are not about to build this type of radio in your basement on a bench. Figure out how many channel;s you want, how much weight you plan to lift and a few dozen variables before you even think about communications.

Sometimes even a $32,000 drone can have a real bad day. Drone used in turnpike bridge inspection crashes into water, that had to be a bad day. Following the demonstration the state decided to postpone buying any.

Before I forget, the maximum effective range comes down to things like power, obstacles and frequencies used.

Ron

I know it is not going to be simple or easy, and that there are certain risks. So does 2.4GHz or 5GHz mean you can transmit up to 2.4 or 5 Gbits per second? And what are the advantages and disadvantages of different frequencies? Also, how much power would it probably consume to transmit at those frequencies and distances?

 

https://forum.allaboutcircuits.com/...ors-and-propellers.151208/page-2#post-1297873 is the thread I have for making the drone.

 

2.4GHz is the RF carrier signal. No, you cannot send 2.4Gbps.

 

2.4 or 5GHz refers to the carrier frequency of the radio signal, which is then modulated.

 

So does 2.4GHz or 5GHz mean you can transmit up to 2.4 or 5 Gbits per second?

No, those are common RF Carrier frequencies. The RF is a carrier and the data placed (modulated) into the RF carrier and on the receiving end it is separated (demodulated) from the RF carrier. The carrier frequency is called a carrier because it carries the data. Actually it is 2.4 and 5.8 GHZ which I believe are popular. Figure a drone with a camera on a gimbal is sending back a live video feed, the video needs a carrier much like TV video and audio need a carrier. Different frequencies have their good and bad points. One merit to high frequencies is that low power can transmit a long way, the downside is you really need a clear line of sight for things to work well and the list goes on and on. RF Engineers devote their entire education and careers to RF technology, it is an entire field unto itself.

I see as I muddle along others have replied so nothing I can really add.

Ron

 

2.4 or 5GHz refers to the carrier frequency of the radio signal, which is then modulated.

Oh, ok. How is it modulated, and what is involved? Also, what frequencies are best to avoid receiving or creating interference?

 

RF is a big topic, you should Google it.

There are multiple different modulation types affecting the amplitude, frequency, or phase of the carrier signal, or some combination thereof. Analog or digital modulating signals can be used.

On something like a drone you probably would want a high frequency, because the length of antenna needed goes down as the frequency goes up. Compare the size of antenna in your cell phone to an AM radio transmitter.

 

Due to the prop size, the drone will have to be pretty large. Possibly up to a 6 or 7 feet wingspan. So as long as it's light, I could have a very large antenna. Also, how do you avoid interference and ensure that the right data was sent, and it all went through?

 

https://www.electronicshub.org/modulation-and-different-types-of-modulation/

 

live wire,its obvious from your questions that you have little or no knowledge about RF. If you really want to build your own drone, I suggest you spend at least five years (or more) studying electronics with RF becoming a specialty. Then you could come back tell us what you built!

 

live wire,its obvious from your questions that you have little or no knowledge about RF. If you really want to build your own drone, I suggest you spend at least five years (or more) studying electronics with RF becoming a specialty. Then you could come back tell us what you built!

Couldn't I find a suitable antenna and RF board, and then use libraries and software others have designed? I am not suggesting I design my own RF system.

 

https://www.droneflyers.com/free-dji-phantom-3-4-ebook/

 

Couldn't I find a suitable antenna and RF board, and then use libraries and software others have designed? I am not suggesting I design my own RF system.

You buy the radio. Before you buy the radio you need to determine how many channels you want. The most basic crude drone will use 4 channels, you need Roll, Pitch, Yaw and Throttle. So you have:

1. One channel for throttle
2. second channel for turning right and left.
3. third channel for pitching forward and backward.
4. fourth one for rolling left and right.

Better transceivers get into 16 and even 32 channels. Add the gimbal that's more channels, how about video and what resolution? How many motors? When you mention a large wingspan you may want an airframe designed around six motors. You buy and not build the radio and communications. But before that you need the entire project laid out on paper.That includes your airframe.

Ron

 

You buy the radio. Before you buy the radio you need to determine how many channels you want. The most basic crude drone will use 4 channels, you need Roll, Pitch, Yaw and Throttle. So you have:

1. One channel for throttle
2. second channel for turning right and left.
3. third channel for pitching forward and backward.
4. fourth one for rolling left and right.

Better transceivers get into 16 and even 32 channels. Add the gimbal that's more channels, how about video and what resolution? How many motors? When you mention a large wingspan you may want an airframe designed around six motors. You buy and not build the radio and communications. But before that you need the entire project laid out on paper.That includes your airframe.

Ron

Why can’t you just send binary on a channel, and send commands like that?

 

Also, I have another thread for the drone. I think I included a link to it in one of my posts on this thread.

 

Why can’t you just send binary on a channel, and send commands like that?

A drones radio receiver / transmitter is connected to a drone control board, this board has a complete microprocessor on board. There is hardware and there is software all of which must work together. You don't just bit bang a few ones and zeros, it is a complex affair of streaming data to a control board which is running all your peripherals including your 4 to 6 motors synchronized.

I suggest you get active in a drone club and if you have any air shows coming up in your area attend them and watch the drones fly, note the electronics involved.

Ron