Could using a 2.4GHz controller frequency interfere with an onboard computer trying to access 2.4GHz WiFi networks?

Question

My situation is this:

I will be building a quadcopter drone (and later a hexcopter) that will most likely use 2.4GHz RC with a Pixhawk. I will also have a computer onboard (Raspberry Pi, either 4B or Zero W) that will have a plugged-in WiFi USB adapter/directional antenna for connecting to and scanning networks. I will communicate with the Raspberry Pi via serial using 433 MHz and ~900 MHz frequencies (one for uplink, one for downlink).

My questions is this:

Would using a 2.4GHz controller frequency interfere with my WiFi directional antenna trying to connect to WiFi networks?

Edit: The general mood of the responses seems to be "eh, maybe." My plan now is to continue in the direction of using 2.4GHz RC, and see how it goes. I've ordered my drone parts (ended up going for a hexcopter because of payload weight) with a 2.4GHz FS-i6X controller. If all else fails, I'll replace the RC method. I'll most likely be using 433 MHz and 900 MHz for RC serial console control up and down, respectively.

Answer 1

The control radio will probably only interfere with the WiFi adapter when it's within a meter or two. Once the drone is flying the signal will be weaker and the error handling should be good enough to handle it.

However the opposite is also true. Once flying, any transmissions from the WiFi antenna on the drone will still be really close to your receiver and will swamp it. That will greatly reduce your range. If you're just passively scanning, you should be fine, but if it involves 2-way communications you could have a problem.

In theory the WiFi and the RC should frequency hop and be on different channels nearly all the time, but the frequencies are close and if the signal is strong enough it can cause a problem. This is usually seen when people try to use a 2.4GHz VTX and RC on a drone. It appears to work at first, but the range is reduced.

I'd recommend finding an old 72MHz radio, or something like TBS Crossfire that gets the RC signal off 2.4GHz.

Answer 2

No.

Radio systems that claim to be "2.4 GHz" don't actually operate on EXACTLY 2.4 GHz. They have different channels a short distance apart.

For example, nRF24 transmitters have an active frequency range of 2400 MHz to 2525 MHz, giving it 125 5-MHz channels.

Many devices will switch to a different channel if interference is detected.

Answer 3

From a strict RF standpoint there will be some interference. This would occur if the RC and Wi-Fi were near the same frequencies, transmitting at the same time, some phase relationship and etc.

The worst case would be operating at the extreme end of the range (distance) where one transmitter is driving hard and the other receiver is getting overdriven. This could cause loss of signal reception.

However, the protocol for the RC and the Wi-Fi are different and they should be able to separate the data they want. Everything else being equal a 900MHz RC control will give better range than a 2.4G.