So what do you do if you want to fly FPV but the winter weather is really bad?
You build a micro FPV quadcopter you can fly around the house!
It is an easy build and the parts are cheap. This is what it looks like:
It consists of a 5.8 Ghz video transmitter and a small camera and an antenna. It is build on top of a standard Eachine H8 Mini Quadcopter. This setup is cheap and still flies for a couple of minutes depending on the type of battery that is connected.
The H8 Mini is a quadcopter with brushed motors so if you would try to connect the video transmitter (vtx) directly you would lose signal due to the power noise from the brushed motors so that needs to be filtered. The vtx runs on 3.3v and the 1S LiPo
puts out 4.2V when fully charged so that would kill the vtx.
Therefore I decided to first boost the voltage to 5V and then use a regulator to bring it back to 3.3v. This way you always provide 3.3v regardless of the exact voltage in the 1S LiPo.
You end up with the following diagram:
Update: there is a small error in the schematic above: the camera ground wire is not connected to ground but audio out, I will fix this soon. Use the labels on the pcb: the gnd wire is the one below the audio out wire.
Please note that the tab on top of the 3.3v voltage regulator (top part of the image above) is not ground (GND) but the output voltage (v-out) so make sure you isolate the whole part well.
I started by connecting a power and ground wire to the H8 mini pcb. It is quite easy to solder a wire to the pads when you remove the battery, you don’t even need to take the quadcopter apart. See this picture:
Next step is to the solder wires to the input side of the Matek board and to the output.The latter are directly connected to the input and ground pin of the AMS1117 3.3v regulator (see schematic above). next I isolated this regulator using shrink wrap and
place it on top of the Matek board. This board was also isolated with shrink wrap and hot glued to the H8 mini. I connected the boscam vtx and the camera to the output and ground wire of the 3.3v regulator. I shortened the antenna wire a bit to save weight and connected the centre wire to the antenna output of the vtx and the outer mesh to the antenna ground pins. This results in the following:
In the future I will try to use a wire antenna as it will be lighter and I may still get good range as the vtx is 200mw.
- Eachine H8 Mini Headless Mode 2.4G 4CH 6 Axis RC Quadcopter RTF
- Boscam FPV 5.8G 200mW Wireless Audio Video Transmitter Module TX5823
- Matek VB2A5V DC-DC 1S Up to 5V Voltage Booster Regulation Module Converter
- FPV 5.8GHz Micro CL TX Antenna Lightweight
- 600TVL 1/4 1.8mm CMOS FPV 170 Degree Wide Angle Lens Camera
- AMS1117 3.3V regulator, search eBay
You will also need some wires and shrink wrap and hot glue.
I use the FrSky Taranis 9XD Plus to control my larger quads so I found a great project online that enables you to control your mico FPV quad using this controller instead of the controller that is provided with the quad, see the nrf24-multipro project on github. You can of course also use the controller that comes with the H8 mini quad.