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  8. Mr.RC-Cam
    Funny and scary at the same time: HeadOCopter.
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  15. Hamed
    yes its important for me because i must use it in my collage project, i did what you said before nothing is burnt the output voltage and the current is ok, i think the problem is one these ic that i dont know what are the part number
  16. Mr.RC-Cam
    I would do a careful visual inspection for broken/burnt components and soldered joint problems. Then I'd check all the voltage regulators for proper output voltage. If these simple steps didn't help solve the problem then I wouldn't spend any more time on it. It seems it is important for you to repair it. Unfortunately success will be unlikely without an accurate schematic, RF test equipment, and access to the often difficult to procure Chinese semiconductors.
  17. Hamed
    Thank you again, in this board there is nothing to control it has only one led that is connected to 5v, i think the unsual 20 pin synthesizer is more likely to be, so now please tell me what would you do if you have these boards, let me know and i do them exactly
  18. Mr.RC-Cam
    Normally the MCU would control the front panel LED/LCD readout and handle the user input controls. I don't know if your device has these things since the information you posted is sparse. I don't see a typical RF synthesizer IC on your board. These are often 16 pin IC's (TSA5520 is popular) with a nearby 4MHz XTAL and EEProm. So perhaps your MCU is a custom device that includes the synthesizer function. Or maybe your board has an unusual 20 pin synthesizer IC (and it isn't a MCU as I thought). I can only guess at these details since I don't have your hardware in my hands. It's really up to you to reverse engineer the circuitry and do further research.
  19. Hamed
    Thank you for your answers, what microcontroller do in this video sender?
  20. Mr.RC-Cam
    My confidence is high that it is a MCU. Due to the location of the 8MHz Xtal the chip's pin-out seems to be similar to a TK68HC05J1A or something like it. But identifying the exact part number would require you to do more research. The nearby 8-Pin IC is likely to be a EEProm. Most of the low-end Chinese microcontrollers have poor code protection that can be disabled. So it's not unusual for Chinese goods producers to obscure the MCU's part number. They think tricks like that will make it more difficult to copy the code, but it's mostly wishful thinking. So why do it? Labor costs are low in China, so taking the time to grind-off some part numbers is common practice by them regardless of any real benefit.
  21. Hamed
    Are you sure that it is microcontroller? If it was a microcontroller there is no need for remove the ic mark
  22. BrainJim
    https://www.youtube.com/watch?v=31HfOOtORyU
  23. Mr.RC-Cam
    It appears to be a microcontroller because of the proximity of the 8MHz Xtal. There's nothing to be gained by determining the exact microcontroller part number. Because you'll need the proprietary firmware that is flashed into it.
  24. Hamed started following Saw filter F480-1
  25. Hamed
    i have a 1.2 GHz receiver that contain such a filer, i want to realize two ic part number that the ic mark is removed can you suggest me some part number please?
  26. Hamed
    Thread starter #1 hi i am a student and i have a video sender that its frequency as the producer said, is 1.2ghz and its not working any more, i want to repair it but the ic part number is removed by producer, can you suggest me any part number for this sender? how can i find components datasheets
  27. Terry
    I should point out that I was using very directional aerials on the receiver which also cuts down the multipathing. Also the same setup did suffer problems one time when I put the tracker on the roof of my car as I was too lazy to set the tripod up so it easy to upset. CP seems to be the thing to go for if your building a new system as linear does not seem to give any appreciable extra range. Linear is simple though and does work for long range high flight with the right aerials. No matter which system is used I would always point the aerial out the bottom though if its practical to do so. Terry
  28. Mr.RC-Cam
    The earth below your feet is a hard RF reflector. So 5.8GHz multipathing will still occur even when you fly high. But every flying location is different; So perhaps start with linear antennas and then upgrade to CP if you experience too much multipathing interference at your field. A few years ago ImmersionRC redesigned the UNO5800 and started using their NWM662JRX NexWavRF module. It has the Richwave Rx chip. Their original UNO and DUO designs had the Airwave chip based Rx module, which only has -85dBm sensitivity. ImmersionRC was a late user of the Richwave Rx chip. Long after the success of the RX5808 (which uses Richwave chip) they took notice and started using it too. There are many suppliers that clone RX5808 modules and other variants. Quality can vary. Two identical vRx's may have different performance. So like many Chinese made FPV products, you have to buy and try.
  29. swake
    I fly with an airplane MTD (My Twin Dream) which is made to fly far and high. The circular polarization is made for people who fly very low among the trees, etc ... When flying high there are no multiple reflections as we are in free field. You do not agree with her? So for me I thought linear polarization was good for high flying. I just found this on this forum: Terry say: The only other thing worth a word is that pointing the aerial out the bottom of your plane is IMO the only way. The short wavelength of 5.8Ghz seems to be blocked very easy by servos or leads or almost anything. You will get interference simular to multipath but it is not. So the frequencies 1.2 or 2.4 for the video are less sensitive to the multiple path? I understand better your question from the beginning. Do you have brands and receiver references using the Richwave Rx chip? I found on google that the UNO5800 use the module NWM662JPX, is it a specific module developed by ImmersionRC or some things like a RX5808 for example because I can not find information about this module.
  30. Mr.RC-Cam
    5.8GHz FPV will be more reliable with CP antennas due to an increase in RF multipathing. You can use RHCP or LHCP; Both the vTx and vRx will need to be the same polarization (don't mix RHCP with LHCP). Most modern 5.8GHz vRx's use the Richwave Rx chip, so -90dBm sensitivity is common. But variations in build quality can affect the actual sensitivity. Advertised sensitivity that is better than -90dBm is probably wishful thinking.
  31. swake
    I'm surprised, I did not think that frequency had a role in polarization ... I will use the 5.8Ghz.
  32. Mr.RC-Cam
    Typical recommendations will depend on the FPV video link frequency. 900MHz, 1.3GHz, 2.4GHz, or 5.8GHz?
  33. swake started following Linear or Circular?
  34. swake
    Hello, What kind of polarization do you recommend for long-distance flying so without obstacles with a plane that always flies in a straight line and flat. Another question, are there any receivers making more than -85 or -90dbm of sensitivity? Thank you
  35. charly

    Landtastic question

    charly replied to kvlasblom's topic in RC-CAM Projects

    Hi, if the question is still actual, perhaps, the change of the servo to the more stable and well balanced can help? In our classes we use this motor. It works great, diagnostics can be done via API.
  36. androidi

    Analog HD FPV Video. Why Not?

    androidi replied to Mr.RC-Cam's topic in Video Piloting (FPV/RPV)

    Ok, so I pondered this thing a bit. After digging some practical information, I found the relevant links. Looking at PAL, which has a higher frequency than NTSC, Wikipedia tells about as much as is needed for determining the data speed. – Both PAL and NTSC are irrelevant after this, except considering the modulation capabilities of el cheapo vtxs.. https://en.wikipedia.org/wiki/PAL So we are looking at 8 MHz max frequency, which is achievable quite easily. First hit points to a TI set (from 1994!): http://www.ti.com/lit/an/slwa022/slwa022.pdf Instead of just sending FM, QAM should be a no-brainer: https://www.radio-electronics.com/info/rf-technology-design/quadrature-amplitude-modulation-qam/what-is-qam-tutorial.php https://en.wikipedia.org/wiki/QAM_(television) 64QAM would give a beefy 30Mbps digital bandwidth, which is more than plenty. (Even for several HD cameras :D) I think I can ditch all that ADV-HDTV-chip sheizze, and just focus on pure signals, as HardRock pointed out. CVBS wrapper would have been a nice twist, but is totally unneeded, and is only limiting the creativity. So, the only thing left is to have H.265 output data from a HiSilicon chip, pass it through vtx-vrx pair, and decode it with another chip on the other end. Easy peasy. The problems start to emerge, when signal quality starts to suffer. By downgrading from 64QAM to QPSK/BPSK the transmission speed is lower, but still more than enough (like 5Mbps or something). One other thing to include would be some kind of error-checking / fixing mechanism. RAID striping with parity comes to mind, but it's designed for hard drives. CRC does not help, it only throws invalid data to trash. Ideally the fixing mechanism could reconstruct some useful data from a low-quality signal. There must be hundreds of these around, it's just a matter of digging one up, and implementing the needed bit-fiddling. It would be superb to be able to change the HEVC encoding bitrate and/or resolution on the fly, by e.g. utilising the RSSI from "controller" rx (that 2.4 GHz thingy), via FC board, or something (I'll have to dig the BetaFlight source some more to get a better understanding of how things work there). Resolution change on the fly could be more of a problem, but I'd imagine changing the bitrate would just be some request to encoder process (depending on the implementation, of course). But remember! Digital link for PAL video only takes some hundreds of Kbps, which already is quite "ground-breaking" (for FPV pilots, that is. The rest of the world already did this like 40 years ago. :DDD).
  37. Aciid started following Analog HD FPV Video. Why Not?
  38. Aciid

    Analog HD FPV Video. Why Not?

    Aciid replied to Mr.RC-Cam's topic in Video Piloting (FPV/RPV)

    I'm interested in working on this subject as well. I've been looking at the commercial solutions for so long and found that following the 802.11 spec is where latency lies. For example in the recent drone Parrot Anafi, they use a combination of 802.11 and rtsp streams. Parrot has made the effort to modify rtsp -library and g-streamer heavily to minimize latency ( down to 100ms, which is still too much ) , this integrated non-SOC implementation can be replicated with the following project https://github.com/bortek/EZ-WifiBroadcast I think I still need more inspection hardware to get involved more in a required lower level, talking about oscilloscopes and evaluation boards for both encoding and decoding. I've been convinced by Androidi theory and boards produced by auvIDEA. (https://auvidea.com/e10/) Fpvmodels "teaser" about building something that can fit quads reveals that they are using a wifi -module from pins in conjuction with a auvIDEA's E10 encoder. seen here https://www.facebook.com/pg/fpvmodel/photos/?tab=album&album_id=154256488115370 https://www.facebook.com/fpvmodel/photos/a.154256488115370/963966883810989/?type=3&theater Their tests for the latency are inaccurate, since they are tied to the devices they are using, but it reveals they are on the path. Really hoping we can gather a good posse to work with, does rc-cam have a slack / discord I can hop into?
  39. HardRock

    Analog HD FPV Video. Why Not?

    HardRock replied to Mr.RC-Cam's topic in Video Piloting (FPV/RPV)

    Laws may be different depending on country, but i sure it's completly legal. Limitations applied only on transmission power for selected frequency, but not for protocol. For example, 2.4Ghz RC transmitters use own protocols, not Wi-Fi, and its completly legal.
  40. androidi

    Analog HD FPV Video. Why Not?

    androidi replied to Mr.RC-Cam's topic in Video Piloting (FPV/RPV)

    From Finland. I guess it won't matter. But I'm not sure if it's legal to actually create radios of any kind in here without the license. So those devices really are dummies. That's beyond great news! No more Arduino tinkering, yesss... I actually have one custom SAMD21/RTOS-project right now, but in a couple of days I will return to this project and start poking around the CCTV board with the HiSilicon SDK. It's great to have more people interested in doing this "the other way around".
  41. HardRock

    Analog HD FPV Video. Why Not?

    HardRock replied to Mr.RC-Cam's topic in Video Piloting (FPV/RPV)

    I have try to pass variable data over radio and this works. I put video input wire of vTX on oscilloscope test signal output pin and see same signal on video output of vRX. It has noise and level shift, but it the same signal as input. vTX is TS832 and vRX is RC805. So vTX and vRX is just dummy modulator / demodulator. Where are you from? Normally you don't need any license when using general purpose frequencies like 5.8Ghz. Nobody care what signal flies in air at given frequency.
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