I use a first person view (FPV) system (camera, transmitter, receiver and display) both under my drone, as well as in a LEGO train (allowing you to get a driver seat view).
Runcam 2 system
The first first person view (FPV) system I used was a Runcam 2 system.
Manufacturer website: https://shop.runcam.com/runcam2/
Despite it's build in battery, it was fairly small (21mm high, 38mm wide, 66mm deep), so fitted in the LEGO train (most action cameras are too high or too wide).
The disadvantage was that the runcam behaves as a wifi basestation, to which you connect the iPad or iPhone. This was not a stable connection. In addition, it interfered with the control of the drone, also at 2.5 GHz. Since I wanted to always be able to control my drone, I turned wifi off, and only made recordings on the included flash card. The second disadvantage was that I was frequently unable to turn the camera on: pressing the on button simply did not turn it on. I bought a second battery, but the problem persisted. After about a year with various results, I gave up using the Runcam 2.
Standard password for the "runcam"
5.8 GHz system
Instead of wifi, I later bought a camera and receiver based on 5.8 GHz transmission. This system simply transmits analog video streams, and is frequently use for racing drones. That advantage is there there is virtually no delay between the time of recording and the display on screen. In addition, when the connection becomes too weak, you will get more noise, but the video feed may still be eligible. This is unlike a wifi connection which has longer latency and drops the connection completely if there is too much noise.
Hawkeye Firefly Fortress Micro FPV Camera
The Hawkeye Micro FPV Camera is an all-in-one system, with combined camera and 5.8GHz transmitter.
Manufacturer website: http://www.cnfpv.com/portal.php?mod=view&aid=104
The modules can be separated (with 10cm wires in between), which allows better positioning in a drone or vehicle.
It allows for a wide range of input power. According to the specs 1S (3.7V), 2S, 3S up to 6S (22 V). In my experience, when connected to a single (1S) LiPo battery, the LEDs light up, but I don't get an image on the receiver. When powered with 2S, all works fine. I had good experience powering it from a LEGO Brick (with 6 NiMH batteries) that was drained to 6.5 Volt total, and the camera still worked fine. Note that the transmitter can only take 3.3-5.5V, but this is properly capped by the camera, which is connected to the battery.
The camera settings can be adjust with a small 5-button touch pad that can be connected to the camera. The settings are displayed as an on-screen display.
The transmitter settings can be adjust with a small button on the main board. a short press cycles through channels (1-8), a 2-second press cycled through the bands (A-F (and H?)), a 5-second press cycles through transmission power.
Available transmission power are: low ("0" mW), for very short distance testing, all LEDs off; 25 mW (1st LED on); 50 mW (2nd LED on); 200 mW (3rd LED on).
Camera resolution is 960 lines.
The receiver is an unbranded "5.8G FPV UAV video wireless transmission". It features a 4.3 inch screen, and build-in LiPo battery (600 mA, 3.7 Volt)
5.8 GHz frequencies
Both the Hawkeye and FPV receiver use their own intricate description to select one of the 48 or 40 channels. This table assumes the out-of-the-box frequencies for the Hawkeye transmitter. It is possible to remove a resistor to allow 72-channels, starting with (more common?) 5865 MHz for A1.
|VTX Name||Frequency||Hawkeye designation||Monitor designation||Possible Interference|
|Boscam A 1||5865 MHz||C8||CH11|
|Boscam A 2||5845 MHz||C7||CH12|
|Boscam A 3||5825 MHz||C6||CH13||wifi channel 165|
|Boscam A 4||5805 MHz||C5||CH14||wifi channel 161|
|Boscam A 5||5785 MHz||C4||CH15||wifi channel 157|
|Boscam A 6||5765 MHz||C3||CH16||wifi channel 153|
|Boscam A 7||5745 MHz||C2||CH17||wifi channel 149|
|Boscam A 8||5725 MHz||C1||CH18||wifi channel 144|
|Boscam B 1||5733 MHz||D1||CH21||(wifi channel 148 is unused)|
|Boscam B 2||5752 MHz||D2||CH22||wifi channel 149|
|Boscam B 3||5771 MHz||D3||CH23||wifi channel 153|
|Boscam B 4||5790 MHz||D4||CH24||wifi channel 157|
|Boscam B 5||5809 MHz||D5||CH25||wifi channel 161|
|Boscam B 6||5828 MHz||D6||CH26||wifi channel 165|
|Boscam B 7||5847 MHz||D7||CH27|
|Boscam B 8||5866 MHz||D8||CH28|
|Boscam E 1||5705 MHz||A4||CH31||wifi channel 140|
|Boscam E 2||5685 MHz||A3||CH32||wifi channel 136|
|Boscam E 3||5665 MHz||A2||CH33||wifi channel 132|
|Boscam E 4||5645 MHz||A1||CH34||wifi channel 128, weather radar|
|Boscam E 5||5885 MHz||A5||CH35|
|Boscam E 6||5905 MHz||A6||CH36|
|Boscam E 7||5925 MHz||A7||CH37|
|Boscam E 8||5945 MHz||A8||CH38|
|Fatshark F 1||5740 MHz||B1||CH41||wifi channel 149|
|Fatshark F 2||5760 MHz||B2||CH42||wifi channel 153|
|Fatshark F 3||5780 MHz||B3||CH43||wifi channel 157|
|Fatshark F 4||5800 MHz||B4||CH44||wifi channel 161|
|Fatshark F 5||5820 MHz||B5||CH45||wifi channel 165|
|Fatshark F 6||5840 MHz||B6||CH46|
|Fatshark F 7||5860 MHz||B7||CH47|
|Fatshark F 8||5880 MHz||B8||CH48|
|Raceband R 1||5658 MHz||E1||CH51||wifi channel 132|
|Raceband R 2||5695 MHz||E2||CH52||wifi channel 140|
|Raceband R 3||5732 MHz||E3||CH53||(wifi channel 148 is unused)|
|Raceband R 4||5769 MHz||E4||CH54||wifi channel 153|
|Raceband R 5||5806 MHz||E5||CH55||wifi channel 161|
|Raceband R 6||5843 MHz||E6||CH56|
|Raceband R 7||5880 MHz||E7||CH57|
|Raceband R 8||5917 MHz||E8||CH58|
|Diatone D 1||5362 MHz||F1||Atmospheric research|
|Diatone D 2||5399 MHz||F2||Atmospheric research|
|Diatone D 3||5436 MHz||F3||Atmospheric research|
|Diatone D 4||5473 MHz||F4|
|Diatone D 5||5510 MHz||F5||wifi channel 104|
|Diatone D 6||5547 MHz||F6||wifi channel 108|
|Diatone D 7||5584 MHz||F7||wifi channel 116|
|Diatone D 8||5621 MHz||F8||wifi channel 124, weather radar|
Beware of technical and legal limitations:
- Only frequencies between 5470 and 5925 MHz are allowed in Europe, so some of the D and E band may not be used! These are marked in red. In the US, the same limitations seem to apply.
- The maximum power for a transmitter is 25 mW, which is not very much. This formally applies to non-specific short range distance (SRD) equipment, for e.g. telemetry and alarming, operating in the 5725 – 5875 MHz range.
- For wifi equipment, operating in the 5470 – 5725 MHz range, the transmit power may be as high as 1000 mWatt, although with further limitations: max 50 mW/MHz, and compulsory use of transmission power control (TPC). Note that this is significantly higher than the max of 100 mWatt for 2.4 GHz wifi.
- Reports on the Internet noted that for clear line of sight, you can get up to 750m on 25 mW, but that is easily reduced to 200m with trees, or 50m indoors. 200 mW power would roughly double that distance. Some people reported flying with 600 mWatt, but stipulated that was in remote locations only, with no risk of interference because 5.8GHz signal are easily dampened over distance.
- Like wifi, a major source of signal block comes from water. E.g. foliage outside, moist in the air, indoor pipes, or those large moving sacks of water called humans.
- Wifi5 (802.11n) and Wifi6 (802.11ac) only use channels 36-64 and 100-144.
- The weather radar may also be a source of interference. The FCC had reserved 5600 - 5650 MHz for "meteorological aids", and the Dutch Doppler radar also operates in the C-band (5.6 GHz).