Hi. I'm sure this has been considered by someone more gifted than me but it occurred to me that it should be possible to find the video out feed from the camera gimbal motor multi ribbon and bypass the gimbal board to an external tx. it would save me mounting a sep 5ghz kit at 200g on the AC so I can see what the camera sees now my board is fried due to upgrades and downloading all my dat files and not using an external cooling fan (silly me). Granted it would be fiddly and maybe the providers of the aftermarket ribbons could do. I'd pay £50 to get the camera feed back.msorage to sad is perfect. Anyone got any thoughts or am I just a dreamer. Dji don't bother chiming in please but all other thoughts welcome.
Camera to fried gimbal board bypass.
- Thread starter Gazzer
- Start date
Unfortunately the gimble board contains a large proportion of the camera electronics, the only components in the lower section of the assay are the sensor board- there will be no usable video signal at that point. Even with an added 5ghz FPV you would probably get no joy even if the gimble board was working, the video signal is seemingly not available in any format that could drive a transmitter unless you could pick it up on the OFDM board somewhere. You won’t find it in the gimble board ribbons.
Video transmission in Ph3 Pro/Adv:
- camera sensor board drives the sensor, receives image data and prepares it to sending via flat wire
- digital multi-line data from sensor is sent via flat wire to Ambarella chip on gimbal top board (the data is not analog, and not serialized)
- Ambarella encodes the video; one stream is compressed for SD-card, another is either compressed (Ph3 Adv) or sent to Davinci for compression
- the digitally compressed stream for FPV is sent via ribbon cable to OFDM board, using USB-based protocol (it comes either from Ambarella USB out or Davinci USB out).
- on OFDM board, the video is received by Cypress USB controller, and deserialized for FPGA
- the Altera FPGA (or proprietary Artosyn chip with the same functionality) encrypts the video data into states for multichannel transciever, and sends it to the transciever
- The Analog Devices transciever (or Artosyn knock-off of the AD chip) does the magic of modulation
- At the end, Germanium-Silicon hi-frequency transistors are used to boost the signal before sending to antennas; only two out of four antennas are used at a time
Conclusions:
- Nowhere on the way the signal is even close to standard analog video.
- If Davinci chip gets damaged, it should be possible to change Phantom Pro board into Phantom Advanced board, with just a little soldering.
- camera sensor board drives the sensor, receives image data and prepares it to sending via flat wire
- digital multi-line data from sensor is sent via flat wire to Ambarella chip on gimbal top board (the data is not analog, and not serialized)
- Ambarella encodes the video; one stream is compressed for SD-card, another is either compressed (Ph3 Adv) or sent to Davinci for compression
- the digitally compressed stream for FPV is sent via ribbon cable to OFDM board, using USB-based protocol (it comes either from Ambarella USB out or Davinci USB out).
- on OFDM board, the video is received by Cypress USB controller, and deserialized for FPGA
- the Altera FPGA (or proprietary Artosyn chip with the same functionality) encrypts the video data into states for multichannel transciever, and sends it to the transciever
- The Analog Devices transciever (or Artosyn knock-off of the AD chip) does the magic of modulation
- At the end, Germanium-Silicon hi-frequency transistors are used to boost the signal before sending to antennas; only two out of four antennas are used at a time
Conclusions:
- Nowhere on the way the signal is even close to standard analog video.
- If Davinci chip gets damaged, it should be possible to change Phantom Pro board into Phantom Advanced board, with just a little soldering.
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Thanks Quaddamage ! At one point I spent a lot of time trying to figure out exactly what did what on these P3P gimbal assy's couldn't find anything anywhere explaining the basics..
Now if only I could find some kind of guide lines or procedures to determine, or diagnose what has failed in any given gimbal assy. As it is, i've just been assembling, try it, disassemble then reassembling with different components from other gimbals.........no luck....but I am getting pretty good now at installing ribbon cables.
I'm sorry I digress, but thanks for the info. Any thoughts on trouble shooting gimbal/video issues would be appreciated as well.
Elbert
Now if only I could find some kind of guide lines or procedures to determine, or diagnose what has failed in any given gimbal assy. As it is, i've just been assembling, try it, disassemble then reassembling with different components from other gimbals.........no luck....but I am getting pretty good now at installing ribbon cables.
I'm sorry I digress, but thanks for the info. Any thoughts on trouble shooting gimbal/video issues would be appreciated as well.
Elbert
Most of what I wrote is just reading this schematic:
dji-hardware-schematics/phantom_3_pro_overview.pdf at master · mefistotelis/dji-hardware-schematics · GitHub
It explains the gimbal arms too. You can get understanding of how most things work based on it, although some pages are unfinished.
dji-hardware-schematics/phantom_3_pro_overview.pdf at master · mefistotelis/dji-hardware-schematics · GitHub
It explains the gimbal arms too. You can get understanding of how most things work based on it, although some pages are unfinished.
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