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DIY Micro FPV for $25 | Tutorial

DISCLAIMER
I disclaim all responsibility if you break or damage your equipment when following this tutorial. You’ll follow this tutorial at your own risks

Hi everyone,

After having seen what Flite test did with their Micro FPV module, I thought it was an awesome idea. But too expensive…

I then looked on the internet and found a way of getting the same outcome for ~$25.

I. What do we need?

We’ll need :

  • Micro TX : TX5823, $12
  • Micro Camera : Pinhole 600TVL (Sold with a very narrow lens) $12 or this 600TVL which has a built-in wide angle lens (haven’t tried it but should be working fine!)
  • 1N4001 diode : $0,10
  • Servo Wires + a battery connector : $0,20
  • Soldering gear and hot glue
  • Optional but recommended : Wide angle lens

Quoi-besoin

Avant montage, un poids total de 5,7 grammes | Déjà léger

Before building, it weighs 5,7 grams | Already light

II. Before building

a. Preparing the TX5823

Before putting our components together, you need to know the TX5823 pinout:

TX5823 Pinout

On my version, I didn’t use dip switchs on CH1-CH2-CH3 pins because I don’t need to switch frequencies. The VTX will transmit on 5945Mhz permanently.

However, if you do want to switch frequencies. You just need to solder 3 micro dip switchs on CH1-CH2-CH3 pins on one side and on the TX5823 top on the other side.

b. Preparing the Pinhole 600TVL

There are 4 wires coming from the camera:

  • Red: VCC 3,3V to 5V
  • Black: GND
  • Yellow : Video
  • White : Audio

I advise you to cut the 4 wires ~5cms away from the camera. Then, strip them.

c. Wiring diagram

You’ll need to put everything together according to the following diagram:

Note: You can also supply the set directly from your quad/plane board by soldering the supply cables in parallel with your board’s supply cables. You may then get interference in your video. If so, had a capacitor (from 1000 to 2000µF) in parallel with your supply cables.

UPDATE 04/11/2015 : Since the camera doesn’t like low voltage (when it goes under 3.3V), I recommend you to feed the camera directly from the battery, as shown in the new diagram :

Montage V1.1

 III. Assembly :

a. Antenna soldering :

UPDATE 07/30/2015 : As Vico.C pointed out in the comment section, the antenna length should be 51,72mm if you want a 5.8G wave or 25,86mm for an half wave antenna. I had calculated with the cloverleaf formula. If you used the length indicated on the picture picture below, it’s no big deal since the length is very close to a 5.8G half wave length.

I started by soldering the antenna. In order to save weight, I used a servo wires cut to be 1.04 inch long. Which corresponds to a 5.8G wave. For a monopole, a 5,8G antenna should be 51,72mm (2.04 inches) or if you need a shorter antenna, you can make an half wave antenna wich is 25,86mm (1.02 inch).

Antenne

Une fois l'antenne soudée

Once you soldered the antenna

If you want to improve the range, you can also solder a cloverleaf antenna. Of course, It’ll get heavier.

To do so you’ll solder the copper core of your cloverleaf’s coaxial cable on ANT and the woven copper shield on ANT GND.

b. Diode soldering :

Why a diode? Because the TX5823 accepts no more than 3.3V . Any voltage above this will cause the TX5823 to overheat (note that a badly conceived antenna will also cause the VTX to overheat). The diode will allow to lower the voltage. You’ll then get ~3.3V from a 1S 4,2V fully charged battery.

To solder it, you’ll first shorten the diode’s legs by half. Then, in order to avoid short-circuits you’ll bend the forward leg to 90° and glue it to the TX5823 as shown below:

Diode

 c. Other components’ assembly :

To finish, solder the camera and the supply cable:

Soudure de la caméra

Camera soldered

Montage du câble d'alimentation

Supply cable soldered

Some hot glue and you’re done!

Diode close up

 

close up

 

For only 5 grams!

Micro FPV weight

 

Since some of you have asked me, here is DVR pictures of the Pinhole 600TVL’s quality. It’s good regarding its size and price!

In bright light conditions

In bright light conditions.

 

In low light conditions

In low light conditions.

Posted in Tutorials.

40 Comments

  1. Hello ,, i want to ask you about this assembly …. i have damage my tx 5823 once ,,,,i dont know what i have assembly wrong or what …..my received can came out video ,, but my tx 5823 is very heat ,,,even the hot glue can melt down ,,, what wrong can like this ??

    i saw all your turitorial seem i have not done wrong way ,,,only the lipo i use is 3.7 volt 650 mah is that wrong lipo ? bcause i saw the spesification is 3.3 volt ?

    thanks …hope u can help me

    • Hi Robin,

      Simple question, have you added a diode between the TX5823 and the Lipo? If not, this would be the main cause of your problem!

      If you do have a diode, what kind of antenna did you use?

  2. so if I wire the battery directly to the camera do I still need a diode? and could you show an actual picture of what your camera looks now from different angles or are the pictures displayed already updated?

    • Hi Ethan,

      I’ll try to add photos as soon as possible. The camera is not too bad compared to what I have tried!

      You’ll still need the diode, it’s here to lower the voltage of the VTX actually.

  3. I’m having trouble with RFI from my quad. I have a coax antenna to move the actual radiating part away from the frame about 8 inches and it does not share a circuit with the batteries. However, when I start the motors I intermittently loose signal. How did you deal with RFI?

    • What kind of quad do you fly?
      In order to remain very light, this kit is lacking a filter and won’t support much RF noise. It’s mainly designed for micro quads (Hubsan X4, ladybird…) than for bigger models. If you do want to use it with a larger models, the best way would be to shield the TX module with aluminium foil and tape.

  4. Regarding the monopole antenna size for 5.8 GHz, it should be between 12 to 12.9mm long in the case of a monopole antenna like yours.

    For electromagnetic waves we have:

    F=(C/wavelength),

    where F is the frequency in Hz (5800000000 Hz), C is the speed of light 3×10^8 m/s and wavelength in meters.

    (3×10^8)/(5800000000)=0.05 meter wavelenght

    You wanted a monopole, quarter wavelenght, therefore [(0.051724137×1000)mm / 4]=12.93103425 mm

    /Vito C.

    • Indeed you’re right, I’ll correct this part of this article.
      The antenna used corresponds to a halfwave monopole antenna so the range is still pretty good.
      Thanks for the input!

  5. I guess you didn’t understand me fully, I meant a picture of the new wiring for the camera, and what is the power consumption?

    • Oh okay, I’ll try to upload a new picture asap.
      I don’t have the exact measurements but if think it should be blow 50mA and for the TX around 150mA.

  6. is that 50ma an hour? do you think a 70mah battery with the fpv unit last more than ten minutes?

    • Mmh, that’s short in my opinion. Maybe you should try to build the same unit but with a 10mW VTX. Since you’re trying to build something light, a 100m range should’nt be a problem for you 😉

  7. I have the spektrum fpv unit but it is way less than 100m, what I am asking is what battery do you use and how long do you typically fly with it.

  8. I recommend adding craft foam to the bottom to keep it from shorting out and anti vibration of some sort

  9. the build works fine… BUT… the soldering to the TX is very difficult with such tiny contact points.. then the TX gets a bit warm when its running, it was not hot to touch, but even so it melted the crap plastic wiring on the camera, which shorted it out and it all went up in smoke….
    If you build this it will work, but I would keep all the camera wiring away from the heat sink on the tx.. run it over the back side instead and it should be fine..

    • Thanks for the input. You were not lucky =/
      I always use plenty of hot glue in order to avoid short circuit to happen. It has happened to me too many times by the past 😉

      • not so much unlucky as stupid, its my fault for letting it short…
        I found that the black gnd wire from the camera was melted away and the diode had burnt out, since then ive been trying to get all the adhesive off the camera to see if its ruined,
        The TX definitely is, two of the tiny solder tag points have now come away, so there is no way to get re-soldered to those spots …

    • Hi O.F,

      It’ll work with fatshark goggles as long as you have a NexWave Beta Receiver or the last Raceband RF module. If you have an ImmersionRC/Fatshark RF module (that you find in most Fatshark goggles) it won’t work!

  10. tried to post several times, but somehow didn´t work properly.

    verry nice tutorial.
    Is it possible to use a diode like that Semikron Smd-Schottky-Diode Sk 12 Sma (1A, 20V)?
    have some here and maybe i can avoid ordering the ones you mentioned.
    i m new to diy fpv and electronics, maybe you could help me.
    Thx.

    • Hi Chris,
      Thank you for your comment!

      I don’t think you should use this diode. As far as I know Schottky diodes have a lower voltage drop than other diodes. Though, in this particular application we use the diode to lower the voltage as much as possible to prevent the TX to overheat.

  11. Thank you for fast reply.
    Decided to take a different tx (fx758) and use a pololu 5v step up.
    Adds little weight but I can use my other cam too.

  12. I noticed that your pictures of the whole setup don’t have the same connections as your electrical diagram. I am about to start soldering mine together but need some clarification about the power wire. Should the camera be powered directly from battery or shared with the diode’s output voltage? I read on banggood this camera takes 3.7-5V, and the tx5823 takes 3.3V. Do you know what the output voltage after the diode is? Thank you!

    • Hi Dillon,

      Sorry for the late answer. To clarify, at first I had the camera supplied by the diode output but I realized than when the Lipo battery was half discharged the diode output was going under 3.3V and thus wasn’t supplied correctly (going black & white).

      Long story short, connect the camera directly to the battery and you’ll be fine 😉

    • I built an fpv system with the help of this tutorial and found that the camera gave a better image when powered by the lipo directly, instead of through a diode (grainy) or a 5v step up (horizontal lines and weird color effect).

      The TX5283-1202something that Banggood sells at the moment gets too hot at 5v, even though they say the voltage can be from 3.3 to 5.5 Volts. I removed the heatsink and confirmed this version has a voltage regulator that steps down the 5.5 to 3.3, thus producing heat, so you can power through the 1s lipo or use a 5v step up but i chose not to.

      I chose to run the camera with the 1s and the transmitter with 3.3v from the same lipo that power my V911 heli. The oscilation of the voltage generated by thw motors causes interference on the video. The best solution is one of those stepup&stepdown modules by pololu but their price and shipping cost was almost half the price of my heli. Thus, i bought of those blue 5v usb step up modules from ebay and a 5 to 3.3v AMS1117 step down modules for a total os €1.25. Note that the fully charged battery stands at 4.2v so i couldnt simply use a the AMS1117 , has the difference between inputh and output voltage has to be over 1.2V, therefore i steped it up to 5V first.

      Total weight is 6.2 grams and cost is around €15 euros for the transmitter.

      For the receiver, I used the RX5808 running at 3.3V and powered by the USB video capture device (UVC) also sold by banggood, that is connected to an Asus EEE 901 running Lubuntu, using guvcview as external webcam capture and recorder.

      Both TX and Rx were tuned to 5645MHz by soldering CH3 to ground. The antennas are vertical dipoles cut to quarter wave length of 5.8GHz freq, that is, 12.26mm, considering the 95% velocity factor of the wire.

      • Thank you for your input Vito C !
        I see that went through a lot to get it to work correctly ! I had abandoned the option to power it directly from a quadcopter main battery. I had tried with a Hubsan X4 and the lack of filtering in the TX5823 made it impossible to use.
        So the AMS1117 also worked as a filter as I understood ?

  13. Hi! I am very interested in this build, and have all of the parts except for the diode. Could you possibly advise me which one to get and where to buy it from? Maybe even a link? Thank you so much!
    Colin

  14. i have had very good luck with this camera, the vtx does not need the diode and i found that it uses boscam bands, not fatshark bands, the nexwave is only for the domi’s, i have done some research and have found no tx module that will support fatshark frequencies, there are also other vtx’s that are similar to the va1100 (spektrum micro fpv) that have more power and they are a higher quality but lower price

    • Well, normally the VTX should run at 3.3V. Some people reported that using it with higher voltage that 3.3V will cause it to overheat. That’s why I had decided to had the diode. Indeed this module uses Boscam Bands.
      The latest generation of Fatshark RX modules receive 32channels including Boscam Bands. We’re not forced to use Fatshark band VTXs anymore ^^

      • Hi,
        Upon throttling up on the quad that I am using this on (tiny whoop) the video goes straight to static. With no throttle, the video is clear as day. What could the problem be? By the way I also tried the cam on the blade glimpse, with the same result.
        Thanks!

  15. Hi,
    Upon throttling up on the quad that I am using this on (tiny whoop) the video goes straight to static. With no throttle, the video is clear as day. What could the problem be? By the way I also tried the cam on the blade glimpse, with the same result.
    Thanks!

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