FPV

Finally received GOPRO2!

jedas — Thu, 19 Jan 2012 18:26:09 +0000

Finally came my GOPRO2 from USA. New and improved. Better resolution, handles dark better, more pro. Haven’t installed it on a plane yet, but took it on my ride to work. It was pitch black, so you can evaluate how it works at night. It’s not a night camera, but even at such conditions it’s sensitivity is reasonable. I promisse to make more videos during the daylight, once I see it.

Video taken 1080p at 30 fps.
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Dodging cliffs by PeeMax in Iceland

jedas — Wed, 04 Jan 2012 06:18:00 +0000

Simply great flying.

Flown with Dragon Link LRS
Plane: Bixler
2.4GHz 1000mw Tx (using 2.35)
Tx antenna:IBcrazy’s half wave dipole
Rx antenna: 11dbi Omni from hobbyking
Turnigy Basic FPV goggles
GoPro HD Hero2 recording 60fps at 720p

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Video on the internet: FPV adventures

jedas — Tue, 22 Nov 2011 20:30:32 +0000

Some video I’ve found on RCG. Nice scenary, music and action.

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Converted DOSD power supply to linear

jedas — Tue, 22 Nov 2011 19:00:46 +0000

My gps unit was unable to lock stable signal. I’ve found out that interference source was DOSD swithing power supply unit. I’ve removed it, and inserted linear 3.3V voltage regulator (LM1117-3.3). Works like a charm. Stable satellite lock near window where was no at all.

Adjusting video level on DOSD

jedas — Thu, 17 Nov 2011 21:46:31 +0000

While lines
I’ve recently purchased DOSD. The first I wanted to fix was these white lines on the screen. They appear if black borders are enabled in the settings and signal is fed through RF video link. When DOSD is directly connected to the goggles or the computer, this problem is not noticeable.

As I’ve noticed on youtube clips this problem is not rare one. Few of my friends has bought Dragon OSD and had the same problem.

The problem is in the black level in the composite video signal

As you may notice on the scope view, very short bursrs of signal means white letters being drawn on the screen with black border. The lower amplitude is, the darker the view is. But it should stay above reference black level, which goes right after the sync signal. Here we see, that it goes under. That probably confuses video TX or maybe RX AGC. You may hide this problem by loading video signal with parallel resistors on the composite cable, but this might degrade your contrast, colors or even a synchronization. THIS IS NOT A MAXIMUM VIDEO LEVEL PROBLEM!!!

When I’ve looked at the DOSD PCB I’ve found that two signals comes from microcontroller. One of them draws white pixels, another is for black ones. White pixels right now probably is not the part of the problem, so I’ll draw only the black color part . This scetch shows how the parts are connected (guess only, based on observation):

Accidentally I’ve damaged onboard transistor, and tried to replace it with pin-to-pin compatible BC847 (100MHz). This general purpose NPN transistor seems too slow for this task, the image was very shady. So I’ve searched and found very good and kinda cheap transistor: BRF93A. It is able to work up to 6GHz (!). It worked really nice. Not sure what was the original part number, but text in the picture now is crystal clear.

To limit voltage being shorted to ground by transistor, I’ve inserted 100 Ohm resistor on the emiter, and it solved a problem. You can see in the video how I’ve tried adjustable resistor to find optimal blackness level in the picture. There was no slot for the load resistor, so I had to lift transistor and solder 100 Ohm resistor nearby. Not very elegant, but .. it works.

As you may see, I have great picture in the screen. With solid black border and no white shading .

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Hope this will help someone to improve the image!

_________________

Never tried, but maybe there is even easier way to solve this, by increasing marked resistor:

FPV range calculator including terrain topology

jedas — Fri, 21 Oct 2011 05:29:56 +0000

Ligowave has created very useful radio link calculator http://www.ligowave.com/linkcalc/, which evaluates terrain topology, Frenell zones, radio wave attenuation, rain and foliage. You need to point on the map where are you going to fly, enter your frequency, tx power in dBm (~27), receiver sensitivity (~ -95), antennas height and you get the results. There are two modes. One calculates if you are yousing directional antenna, you’ll get information about link margin. Another point to multimpoint (P2MP) mode calculator assumes you are using omni antenna in the ground station. Even program is designed for digital links, it’s quite good for analog FPV videos too. Free registration required to use this tool.

GoPro employed

jedas — Fri, 21 Oct 2011 04:23:54 +0000

Chasing Twinstar2 with Twinstar2. It was very windy, so planes were difficult to aim at. Next time will be better! Footage is 1080p, 127 degrees FOV.

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TS2 crashed because of empty battery. Headwind was quite strong.

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Trying to reach 7km with Twinstar2

jedas — Mon, 19 Sep 2011 10:27:40 +0000

This time I was not able to achieve roundtrip. Even the plane reached 7 km, the battery depleted on the way home. No damages this time.

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Twinstar2, 8×4 props, 100ish g motors.
2700 mAh 3S1P Zippy 25-30C battery
Sunsky 500mW vtx + inverted vee antenna
Lawmate vrx + 11 dBi biquad 1280 Mhz antenna
ChainLink @ low 200mW power mode.
Smalltim OSD, modified for CL LRS
Fatshark cam

Testing biquad antenna, perfect picture over 4 km

jedas — Tue, 13 Sep 2011 19:45:30 +0000

After 2km flight with omni antennas, I've decided to make biquad antenna described by IBCrazy. It impressed me how good this antenna is. I had no video reception problems what so ever for the whole 4km flight.

RSSI level shown by OSD is not calibrated, so it show no RC control, even I had a solid control and no failsafe's.

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Finally reached 2 km range

jedas — Mon, 05 Sep 2011 05:02:15 +0000

I’ve tested my new Lawmate 1.2 GHz video rx. It seems it’s quite good receiver. Sensitivity was slightly better than sunsky rx, but selectivity is much better. It was quite immune to nearby 433 MHz LRS, contrary to sunsky vrx. Due to omni antennas signal wasn’t very strong, but good enough to do the flight.

Twinstar2 3S 2600 mAh, 8×4 APC. Inverted Vee antenna for 400mW @1280MHz sunsky video tx, omni stock antenna on lawmate video rx. Archos AV500 DVR. ChainLink 433MHz LRS stock antenna 200mW mode. Fatshark camera. Also fatshark 2.4 GHz 100mW video tx on ground station, to retransmit signal to fatshark goggles.

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New ground station, new LRS

jedas — Sun, 29 May 2011 06:44:15 +0000

Finally I've purchased ChainLink LRS. It has switchable power between 0.1mW (range test, 0.2W and 0.5W). 12 Channel receiver. We've tested it in the city without ling of sight, signal faded in 2.4 km, which was very similar to popular DragonLink (DL). I've modified Smalltime OSD to show RSSI level. Problem was in SN777 camera which was very noisy. I've did modification to remove that noise (will be described later). I've did some changes to the ground station also. I've used photo camera tripod. That helped to reduce multipathing. I've attached 100mW 2.4 GHz fatshark transmitter near after 1.2 GHz receiver to retransmit the signal to the goggles. It gives more freedom around the GS. The main reason I've did this, to reduce CL influence to video receiver, because atleast 2 meters are recommended. [There is a video that cannot be displayed in this feed. Visit the blog entry to see the video.]

Fatshark review

jedas — Fri, 18 Mar 2011 21:30:28 +0000

Recently I’ve bought FatShark 2010 Aviator edition video goggles. I’ve been using laptop as my primary navigation screen. I’ve started with EasyCap USB video adapter. It was very cheap (~7$), and very crappy product indeed. Then I’ve switched to Avermedia PCMCIA adapter. It was ok. The mayor problem is laptop screen itself. It’s very difficult to seen even there is moderate sun light outside. Even the laptop is in the dark car trunk, reflections are still very bad.

So I finnaly decided to get these goggles which I’ve heard so much about. Aviator edition is different from standart edition, because it has integrated 2.4Ghz or 5.8 GHz video receiver. Also it came with 100 mW transmitter. I didn’t tested it outside, but I don’t expect much from that power.

I had VR920 video goggles before, so I can compare them. First of all, the things I like:

+ Good field of view (FOV). It’s declared as 40ish degrees. It would be nice to have more, to get even more immersion, but it’s really enought to navigate and feel yourself in the plane. This is where it outperforms VR920.
+ Good contrast. My camera doesn’t produce good colors, so I can’t tell if there colors are good, but picture is quite good.
+ Really good sun shading. Foam around the eyes completely covers everything around, even with the bright sun outside, I’ve seen only screen. No silly caps or covers needed.

I know it’s not a big list, but it’s very important freatures in FPV goggles I think. Now what I didn’t like:
- The most important issue for me with this goggles is eyes fatigue even after very short usage. I must admit my eyes are quite bad, maybe there is something to do with it. But few people with good vision also confirmed this. I think there is something to do with focus distance and eye degree. The goggles are focused for 2 meters virtual distance. But eyes are looking straight forward, parallely into infinitive. Eyes quickly adapts to this and you can see fine in the goggles, but when you take it off, eyes needs to readjust and it feels sick for a few moments. Maybe this is something I need to get used to, but I didn’t like it at all!!!
- Lenses are very close to the eyes. Some people complained about it, personally I had no big problem with that. I guess it was needed to achieve such good FOV.
- Even you can change lenses distance to fit the distance between the eyes with two sliders in the front, it’s almost impossible to get clear picture in the whole screen. Sometimes left, sometimes right, or sometimes both sides are blurry. It’s not very big issue for me, because my osd shows main information near the center of the screen, but other people, could have some problems with osd like dragon OSD. They say that 2010 edition fixed this problem. I wonder how horrible it was before this edition?
- Battery charged came in US mains plug version. I need to buy aditional adapter to use it. I had to cut the cable, fir the T connector and use it with my primary battery charger.

Here are some pictures:

I like this label “inflatable shark not included”.

It’s not easy to take a picture of the view, because you need to be really close to the lens to see the whole picture.

This 100mW transmitter came with simple wire attached instead of antenna. I can live with that if it’s tuned to right frequency. I didn’t tested yet properly, but I’m sure inverted vee antenna will outperform this wire.

I hope this review will help you to decide if you want to purchase this unit. They are not great goggles. They are ok and do their job. Not sure if it’s possible to get anything better for such price though.

TwinStar first launches

jedas — Fri, 18 Mar 2011 06:30:16 +0000

Incorrecg CG and some other problems. Will be fixed soon

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Let’s see some twinstars

jedas — Fri, 18 Mar 2011 06:26:57 +0000

Right now I’m assembling my plane, so there is no much to show. Rather see some Twinstars made by others:

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Server upgrade

jedas — Sun, 13 Feb 2011 18:51:44 +0000

We’ve finished server upgrade. Now pages will work even faster.

Hexacopter in Cameroon

jedas — Fri, 21 Jan 2011 21:15:45 +0000

William Thielicke (Mr. Shrediquette) from Cameroon

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Calibrating OpenPilot quadrocopter

jedas — Sun, 09 Jan 2011 19:16:42 +0000

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Trying new DVR

jedas — Mon, 27 Dec 2010 14:20:26 +0000

Archos AV500 60GB

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Kaip išsilaikyti radio mėgėjo egzaminą ir legaliai skraidyti su 1.2 GHz video siųstuvu

jedas — Sat, 27 Nov 2010 21:35:58 +0000

Apribojimai
Kadangi FPV skrydžiams reikalingas video siųstuvas RC mėgėjai renkasi iš esamų rinkoje analoginių video siųstuvų. Pasirinkimas nemažas, tačiau transliuojami dažniai paprastai būna šie: 900 MHz, 1.2-1.3GHz, 2.4 GHz ar 5.8 GHz. Kai kuriose šalyse galima naudoti tik tam tikrus diapazonus. Pavyzdžiui Europoje yra draudžiamas 900 MHz dažnis, nes jis naudojamas GSM sistemose. Lietuvoje 2 diapazonai patenka į dažnių nereikalaujančių specialaus leidimo, t.y. 2.4 ir 5.8 GHz. Tai vadinamasis ISM dažnis.

Tačiau nors leidimo šiem dažniams ir nereikia, yra ribojama galia kurią gali spinduliuoti siųstuvas. 2.4 GHz skaitmeninei moduliacijai leidžiamas 100mW spinduliuotė, kai tuo tarpu analoginiam video leidžiami tiktai 10mW. 5.8Ghz ruože atitinkamai 25 mW. Kas yra bandę tokius galingumus, pastebėjo, kad realus jų panaudojimas galimas tiktai 100-200 m ribose. Bendru atveju tolimiems skrydžiams tokios galios neužtenka.

Ka daryti?
Kai kurie RC mėgėjai į šiuos apribojimus nekreipia dėmesio ir skraido stengdamiesi niekam neužkliūti. Vis dėlto administracinės teisės kodeksas ir numato ispėjimus, baudas ir/ar įrangos konfiskavimą už šitokią veiklą. Ar tie žmonės kelia žalą ir trukdo kam nors, nenagrinėsiu. Šio straipsnio tikslas kitas, ir yra skirtas žmonėms kurie šiame hobyje nenori nusižengti įstatymams, kažko apgaudinėti ir slapstytis.

Pasigilinus į radio mėgėjų veiklą, matome, kad jie gali naudotis įvairiais dažniais. Jiems prieinama nemažai dažnių, tame tarpe ir 1.2GHz, 2.4GHz, 5.8 GHz ir daugelis kitų. Radio mėgėjai šiuo metu skirstomi į 2 kategorijas: A ir B. Žemesnioji B kategorija leidžia naudotis 1.2GHz siųstuvais iki 5W, o A netgi galingesniais. FPV mėgėjai puikiai žino, kad netgi pusė vato yra per akis skrydžiams keliolika kilometrų. Iš principo radio mėgėjai pagrinde šiuos dažnius naudoja telegrafo, balso pranešimams siųsti. Tačiau taip pat egzituoja mėgėjų televizija (ATV). Lietuvoje radio mėgejams leidžiama naudotis 1240 – 1300 MHz diapazonu. Šiame diapazone IARU Region 1 plano išdėstyme yra 2 ATV diapazonai: 1243.250 – 1260 MHz ir 1272 – 1290 MHz. Paprastai FPV siųlomi siųstuvai turi 1280 MHz centrinį dažnį, kuris patenka į pastarąjį diapazoną. Taig šiuo dažnių galėtume naudotis jeigu turime radio mėgėjo leidimą.

Kaip gauti radio mėgėjo leidimą?

Ką tik gavau radio mėgėjo leidimą, taigi kol viskas neprimiršta pakomentuosiu kaip viskas vyko:

1. Siūlyčiau iš pradžių pasidomėti radio mėgėjų veikla jų puslapiuose, pvz.: hamradio.lt. Šiame puslapyje rasite A ir B egzamino klausimus su atsakymais. Oficialus klausimų sąrašas pateikiamas Ryšių reguliavimo tinklalapyje. Jeigu paskaitinėjus klausimus manote, kad atsakytumėt į daugumą iš jų, galima judėti toliau. Jeigu ne – … google it.

2. Antru etapu reikia pateikti prašymą RRT, kad norėsite laikyti radio mėgėjo egzaminą. Tai galima padaryti atsisiuntus atitinkamą formą iš rrt.lt ir užpildžius nufaksuoti jiems. Tačiau daug paprastesnis ir patogesnis būdas yra pasinaudoti e-bankininkystės sistema. Joje rasite priėjimą prie viešųjų e-paslaugų. Ten susirasite RRT ir atitinkamą šabloną. Gal sistema iki galo neatidirbta, ir tenka pildyti WORD dokumentą ištrinant underline’us ir pan. Bet principe viskas veikia. Šiame prašyme nurodysite kokį egzaminą A ar B norite laikyti. FPV reikmėms siūlyčiau B, nes jis daug paprastenis. Vienintelis galbūt aktualus minusas, kad galėsite naudotis šiais dažniais tiktai Lietuvos teritorijoje. Jei daug keliaujate, gal būt verta pamastyti apie A kategoriją. Taip pat šiamie prašyme nurodykite kokį norite gauti šaukinį. Jis turi prasidėti LY <2-3 raidės>. Aš pasirinkau LY4FPV.

3. Po kelių dienų po dokumento pateikimo, paštu atsiunčiama išankstinė sąskaita faktūra, pagal kurią reikia sumokėti 7 lt už egzamino laikymą. Ta galite padaryti per e-banką.

4. Gavę jūsų apmokėjimą su jumis susisieks RRT darbuotojas ir suderinsite egzamino datą.

5. Pasiruošę egzaminui nuvyksite į RRT būstinę. Kiek žinau visi didieji miestai turi savo filialus, taigi tikėtina, kad toli važiuoti nereikės. Aš prieš egzaminą rimtai pasinagrinėjau klausimus, pasikonsultavau su žinančiais ir pavyko teisingai atsakyti 30 atsakymų iš 30 galimų. Egzaminui užskaityti išlaikytu užtenka 25. Tačiau norėjau išlaikyti kuo geriau, tam, kad parodyt, kad tai nėra per daug sudėtinga. Atsakymus kuriuos radau hamradio.lt yra netikslumų ir manau, kad 4-6 klausimai yra atsakyti neteisingai. Kai kuriuose klausimuose yra dviprasmybių ar neaiškumų, kaip ir visose taisyklėse. Jeigu kažkam iškils klausimų, galėsime aptarti juos plačiau.

6. Išlaikius egzaminą, atsiunčiama išankstinė saskaita faktūra už leidimo išdavimą (4 lt). Apmokėjus ją, paštu ateina leidimas su RRT direktoriaus įsakymu, leidžiančiu radio mėgėjo veiklą. Sveikiname, jūs radio/fpv mėgėjas. Finito

Apie naujai galiojančius šaukinius taip pat pranešama rrt.lt svetainėje.

Po egzamino šnektelėjome su RRT darbuotojais apie FPV veiklą. Ši veikla jiem puikiai žinoma ir jų darbas yra reguliuoti, kad mūsų veikla netrukdytų kitiems. Jų nurodymai yra paprasti: netrukdyti kitiems radio mėgėjams, ypac dirbantiems 1296 MHz danžiu, nes, kaip supratau, šiame dažnyje dažnai vyksta varžybos. Taip pat neužlipti ant švyturių ir retransliatorių dažnių.

Keletas dalykų kurie aktualūs FPV:

1. Pagal esamas taisykles negalima perjunginėti dažnio veikiančiame siųstuve. Ne visi video siųstuvai turi tokią galimybę. Dažnio išstatymas trumpikliais šiuo atveju yra korektiškesnis nei mygtuko paspaudimu šokinėjimas per dažnius.

2. Esant transliacijai būtina perdavinėti savo šaukinį kas 5-kias minutes. Geriausiai tam tinka OSD. Saviškį OSD suprogramavau taip, kad ekrano viršuje visada būtų matomas šaukinys:

Kolkas trumpai tiek, gero ryšio
LY4FPV | jedas

Dėkui:

Arnui, Mariui, Zebediejui už rašybos klaidų pastabas.

Tadui, Augustinui už suteiktas konsultacijas radio mėgėjų veiklos klausimais.

————————–

Mano nuomone neteisingų atskymų sąrašas pateiktas hamradio.lt:

112. Dažniais, kuriuose maksimalus signalo juostos plotis neturi viršyti 200 Hz, galima naudoti šią moduliavimo rūšį:

Pateiktas atsakymas: 3. SSB. Mano versija: 2. CW

Komentaras: CW morzės kodo perdavimui užtenka iki 200 Hz juostos pločio, SSB moduliacija reikalauja 2700 Hz.

111. Kokia maksimali leidžiama siųstuvo išėjimo galia B klasės leidimą radijo mėgėjų veiklai turintiems radijo mėgėjams 70 cm diapazone?

Pateiktas atsakymas: 3. 1000W. Mano versija: 1. 50W

Komentaras: Remiuosi RRT dokumentu “Reikalavimai radijo stotims, B kategorija”.

121. Kuriame radijo mėgėjams skirtame diapazone leista veikti siaurajuostės FM siųstuvams?

Pateiktas atsakymas: 15 m. Mano versija. 1. 10 m

Komentaras: Remiuosi IARU organizacijos rekomenduojamu dažnių išplanavimo dokumentu IARU_Regio…lan_2009.pdf.

122. Kuriame radijo mėgėjams skirtame TB diapazone leista naudoti CW siųstuvus?

Pateiktas atsakymas: 1. Tik 10 m ir 15 m. Mano versija. 3.Visuose

Komentaras: Remiuosi IARU organizacijos rekomenduojamu dažnių išplanavimo dokumentu IARU_Regio…lan_2009.pdf.

123. Kuriame radijo mėgėjams skirtame diapazone leista naudoti AM siųstuvus?

Pateikta versija. 1. 80 m. Mano atsakymas: 3. 10 m

Komentaras: Remiuosi IARU organizacijos rekomenduojamu dažnių išplanavimo dokumentu IARU_Regio…lan_2009.pdf.

288. Kuri elektros srovė pavojingesnė žmogui?

Pateikta versija. 3. Abi vienodai pavojingos. Mano atsaktymas 2. Kintamoji

Komentaras: Remiuosi http://www.mokslai.lt/referatai/kursinis/teismo-medicina-puslapis2.html

295. Kaip geriausia apsaugoti radijo stoties aparatūrą nuo žaibo išlydžio?

Pateiktas atsakymas: 2. Atjungiant visą aparatūrą nuo įžeminimo grandinių. Mano versija: 3. Atjungiant visą aparatūrą nuo maitinimo linijų ir antenų.

Komentaras: Ta patvirtintų bet kurio prietaiso jungiamo prie antenos ir elektros tinklo vartojimo instrukcija. Įžeminimo atjungimas neapsaugos nuo žaibo pataikymo į anteną.

Is it possible turn around inside the building?

jedas — Sat, 09 Oct 2010 07:20:25 +0000

Virgis tries to flight into building, turn around and come back. Almost happened

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I was flying around. It’s getting really dark. Nice light cast from the tractor.

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51 Crash Team: Low and fast

jedas — Tue, 05 Oct 2010 05:57:01 +0000

The best of Virgis

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FPV range calculator

jedas — Thu, 30 Sep 2010 06:03:58 +0000

Try this experimental range calculator:

http://www.fpv.lt/lang/lt/fpv-range-calculator/

5.8 GHz video transmitter test

untitled — Mon, 27 Sep 2010 18:41:14 +0000

First test of 5.8 GHz video transmitter. There was 2.4 GHz RC control used and it served good for about 400 meters. As a result we have few poped Lipos and a great video
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Monumentum

jedas — Wed, 18 Aug 2010 14:36:25 +0000

Short flight near Kaunas

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Gliding

jedas — Mon, 16 Aug 2010 10:13:42 +0000

I had a chance to pilot a real glider for the first time. About 10 minutes of my own flight. Seriously cool stuff. Then instructor took over control and showed what the glider is really capable of. It means loops, free fall, “diving on the wing” etc.. Unfortunately there were no thermals due to very hot weather.