special project using drone tech

Discussion in 'First Build' started by 2aBaCa, Mar 29, 2019.

  1. 2aBaCa

    2aBaCa New Member

    Hello all,

    Been lurking for a while as im interested in building drones. right now im on another project. I am looking to build a remotely operated video camera using drone tech Basically like a flighless drone mounted staionary that the camera can be controlled (pan/zoom/tilt) with a range of a mile + direct line of sight and from a smartphone. Obviously i dont need motors or a quad frame, weight is no concern. needs the ability to add extra/ larger batteries for extended run time.

    Can someone list off or point me to the bare neccesities I need to accomplish this?

    Thanks in advance!

    -B
     
  2. wafflejock

    wafflejock Well-Known Member

    I think you'll be a bit hard pressed to get a cell phone to talk at that distance without using the cell network itself, with just wifi the typical expected range (without some sort of directional antenna) is about 300ft https://www.quora.com/What-is-the-range-of-the-Wifi-in-5Ghz-and-2-4GHZ

    For the pan/tilt/zoom camera there are some premade options out there with apps already built for controlling them as well: https://www.amazon.com/Foscam-Outdoor-Optical-Security-Camera/dp/B01MUNOP3V

    If this is more of a just for the fun of it or learning project then DIY could make sense but fair amount of work to get things all working well together. If going the DIY route would look for pan/tilt/zoom models on thingiverse, basically just need a few servos, you can control the servos with any MCU (an arduino would work fine but has no connectivity by itself, there are similar ESP32 or ESP8266 boards that can be relatively easily programmed and have wifi included along with pins that can output PWM which is what you'll need to control the servos). For video transmission typically for DIY quads we use an analog 5GHz video transmitter (VTX) with variable amplification (20mW 200mW or 600mW is a common set of output power options, above 500mW may be regulated depending on location), but these also require a "special" analog receiver and couldn't be directly beamed into a phone (would be much easier to have standalone display hooked to receiver really). For control to get the extra distance you could use a RC transmitter/receiver (many receivers can be hooked directly to a servo to control it with PWM as well, you just need separate power for the servos and shared ground between servo power and MCU power typically).

    There are also MCU boards that can talk over the cell network https://www.particle.io/ <-- this company makes one that is all programmable through a web interface (can edit code online and send out to devices) so makes it relatively easy to get something going too (personally dealing with trying to get TLS working on these embedded devices but it's a challenge unfortunately). If you wanted to actually have the embedded computer handle the video would want a raspberry pi 3 or better for the GPU (also SD card for saving video locally).

    ---

    One other thought I just picked up some of these https://www.amazon.com/gp/product/B07N2P8FCD/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 . Not sure how well they'll work still in shipping but maybe worth checking out for experimenting with. There are also power amplified version of the nRF24L01 with an external antenna that can get a least a city block away (tried one with my RC car)
     
    Last edited: Mar 29, 2019
  3. wafflejock

    wafflejock Well-Known Member

    To clarify a bit too there are different "embedded devices" or microcontrol units (basically a CPU plus memory for a program to be saved and RAM/cache to store the running program, closer to the CPU for higher speed) that might work depending on how much you expect the little computer to do. The Arduino is a breakout board for a chip called the 328P from a company called Atmel (some use different variations of this chip but this is the most common I believe, they are all 8MHz clock speed if no external clock is present and can run on down to 3.5V without issue, if using external 16MHz clock and 5V they can run at 16MHz which is fine for controlling motors and reading basic sensors (light, temp, motion detection with IR etc.), but isn't fast enough to process say 15FPS video, you can drive small LCDs with an Arduino but only at low refresh rate (slightly beefier chip on "Arduino MEGA" the MEGA2560 is used on most 3d printers for running the printer and LCD).

    The ESP8266 and particle boards are using slightly more powerful MCUs somewhere in the few hundred MHz range in terms of clock speed (clock speed says how many operation can happen in a second, if an operation takes 1 clock cycle then it takes 1 second divided by clock speed in terms of real time, so every 1/16,000,000 of a second the atmel chips can do a very simple operation, whereas a ESP8266 or particle board is more like 1/300,000,000 of a second to do an operation (most operations take 3-10 clock cycles). The ESP32 is a minor upgrade on the ESP8266 (both have wifi and I believe bluetooth) the ESP32 adds an extra processor core (dual core) so can handle the wifi/radio at the same time as doing something else (reading sensors processing data etc.). None of these mentioned so far have HDMI or an interface for a camera though so this is where you get into raspberry pi territory (does have HDMI and camera support built in).

    So basically my thought is either go with prebuilt, or go with simple MCU plus VTX so the MCU isn't handling the video (but still need some way to send control signals to it hence maybe particle boards with cellular if you really need long range control), or go with raspberry Pi or similar for handling it all in one.
     
  4. 2aBaCa

    2aBaCa New Member

    How does a drone like dji get out to a mile?
     
  5. 2aBaCa

    2aBaCa New Member

    Thank you for your input.

    What im working on is setting up targets for long range with wireless cameras close to the targets at up to a mile. Size and weight is of no concern, in fact I will probably end up boxing it in 1/4" steel plate to protect it anyways. I might ditch the pan/tilt for simplicity, zoom would be nice, 4k is ideal.

    That being said are there wireless repeaters or extenders that would get the range im looking for?

    I have a buddy that dables in arduino, i may have to recruit him.
     
    wafflejock likes this.
  6. wafflejock

    wafflejock Well-Known Member

    https://www.heliguy.com/blog/2018/08/20/dji-transmission-systems-wi-fi-ocusync-lightbridge/

    ^^ write up here has more info than me on this one but just telling you my experience with regular wifi is the range is much more limited than 1 mile (it all depends on what is between the transmitter and receiver and the power output on transmitter and receivers ability to amplify whatever signal it gets in and eliminate any noise from the signal) . Long story short they use some proprietary technology and modified versions of the standards wifi and the really long range only works with their gear on both ends, also found a forum post asking the same thing and most users say the claimed range is above what they ever actually get (ideal conditions like miles per gallon on a car, driving on a flat surface with no wind in perfect temperature).

    There are repeaters/extenders or just plain directional antenna on the main transmitter that will improve signal strength in one direction and can get really crazy with those if you can pay the price and deal with setup

    That said I think going over the cell network for control input to the pan/tilt/zoom setup is the best way to deal with that since you don't need low latency and will get the greatest distance from cell connection (down side being monthly connection cost but think particle.io keeps their prices pretty reasonable). The video you could transmit with a VTX but they typically work at 5.8GHz which isn't as good for range compared with longer wave lower frequency 2.4GHz signals (personally like this because I'd rather video gets fuzzy before my control signal goes out in most cases).

    Also just wanted to say a 600mW 5.8GHz can get the signal pretty far especially if there are no hills or vegetation in the way I usually run my VTX at 25mW or 200mW because it's enough and will get less interference with it's own signals bouncing off of things (600mW seemed to cause some issues, may have been getting the bounced signals or may have just been too much power draw for the PDB)
     
    2aBaCa likes this.

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