VGA Extender (solved) - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: June 07, 2022, 11:59:42 am
content: I need to prepare a very custom setup that includes a wild hack of one of IKEA's cheap standing tables.The desk is equipped with two electric motors to move the work table (IKEA wood) vertically plus up to 18Kg or workload.On the worktable I have to install three 22" NEC VGA LCDs (4Kg each), connected to a machine that I am building with such old video technology.Don't ask me why, but I have to use CAT5 cables for the VGA, and here is where problems arises: inferences! VGA has three analog signals for the colors {R, G, B}, with two digital signals for timing { V, H }, plus a simple i2c bus to query the monitor.You can write these signals to a RJ45 connector, an use a CAT6 cable.You can even remove the i2c bus and pair twistCode:RJ45.pin1: VGA.R \/\/ twisted pair0RJ45.pin2: gnd /\/\ Ethernet Cat6RJ45.pin3: VGA.G \/\/ twisted pair1RJ45.pin4: gnd /\/\ Ethernet Cat6RJ45.pin5: VGA.B \/\/ twisted pair2RJ45.pin6: gnd /\/\ Ethernet Cat6RJ45.pin7: VGA.V \/\/ twisted pair3RJ45.pin8: VGA.H /\/\ Ethernet Cat6(idea for a VGA-to-RJ45 adapter)with R.gnd = G.gnd = B.gnd = gnd (not a good idea, but that's it)I built one of these VGA-to-RJ45 adapter and it helps a bit with the two motors, but ... since it's a "passive solution", I wonder if there is a better one- true differential pairs via differential OA? (still analog, but it should be less weak about peaks)- VGA over Ethernet 100BaseT (copper PHY)? (digital solution)- VGA over Ethernet 100BaseSX (optical fiber)? (optical digital solution, virtually nothing can disturb light)The VGA cables are only 4 meters long, but they all go together with the 230V power cables, through the same conduit.Code:. ______| |Video1 ===========VGA===========| LCD1 | ______230V ---------- 230V ---------|______| | |Video2 ===========VGA====================| LCD2 | ______230V ---------- 230V ------------------|______| | |Video3 ===========VGA=============================| LCD3 |230V ---------- 230V ---------------------------|______|230v ---------- 230v --------------------\|---------------------/ \| |MotorL MotorRCode:_______________ _______________ _______________| || || || || || || 22inc || 22inc || 22inc || || || ||_______________||_______________||_______________|| |_____Any experience?

author: darkspr1te
author_rank: Frequent Contributor
timestamp: June 07, 2022, 02:39:54 pm
content: Quote from: DiTBho on June 07, 2022, 11:59:42 amYou maybe have to use STP , Shielded Twisted pair CAT5 instead of UTP un-shielded twisted pair.Another technology i've used on long vga runs is balon boxes like this one on amazon[url=https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS]https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS] https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS]https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS]https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS] https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OSwhile this helps it's not substitute for quality STP and keep power keep wires far away and if possible in shielded casing until last inch.darkspr1te

author: DiTBho
author_rank: Super Contributor
timestamp: June 08, 2022, 09:15:41 am
content: Yes, Shielded Twisted pair CAT5/6.

author: DiTBho
author_rank: Super Contributor
timestamp: June 08, 2022, 09:22:54 am
content: Code:RJ45.pin1: VGA.R \/\/ twisted pair0RJ45.pin2: gnd /\/\ Ethernet Cat6RJ45.pin3: VGA.G \/\/ twisted pair1RJ45.pin4: gnd /\/\ Ethernet Cat6RJ45.pin5: VGA.B \/\/ twisted pair2RJ45.pin6: gnd /\/\ Ethernet Cat6RJ45.pin7: VGA.V \/\/ twisted pair3RJ45.pin8: VGA.H /\/\ Ethernet Cat6RJ45.Shield ----------- Cat6.Shieldis this wiring better? or doesn't it help?

author: Ian.M
author_rank: Super Contributor
timestamp: June 08, 2022, 09:38:36 am
content: Nothing you do to the 8P8C ('RJ45') pin order will have a significant effect on the signal quality, provided you don't split pairs, so you might as well stick to standard Ethernet pin order so you can use off-the-shelf cables.However decent quality VGA cables have three individually shielded 75 ohm miniature coax cables for the RGB signals, + an overall double-braid or braid over foil screen.CAT5/CAT6 twisted pair is nom. 100 ohms impedance, and is far more susceptible to EMI even if you use STP, and baluns to match the impedance and keep the signal return paths down the same twisted pair as each signal.Quote from: DiTBho on June 07, 2022, 11:59:42 amReally? or is it just far far far more convenient to use CAT5/CAT6?Using real fully screened VGA cable with restricted access would probably involve cutting the plug off one end, then fitting a new one after threading it through, which is an expensive PITA even if you have the correct crimp tooling for DE-15 connectors (and a far greater PITA if you have to use a solderable DE-15 connector), but its not impossible. Impossible would be if you couldn't accommodate the OD of decent quality VGA cable.

author: DiTBho
author_rank: Super Contributor
timestamp: June 08, 2022, 11:47:29 am
content: Quote from: Ian.M on June 08, 2022, 09:38:36 amOkQuote from: Ian.M on June 08, 2022, 09:38:36 amOK, now I understand why. ThanksQuote from: Ian.M on June 08, 2022, 09:38:36 amThe diameter of the conduit does not allow to pass three VGA shielded cables shaft together with four 230V cables.CAT5/6 have a smaller diameter, and look decent enough. Yes, here it's a matter of convenience; SC optic cables have smaller diameter, unfortunately VGA<=>optic converters are very expensive, 130 UKP each.If they cost less, I would have no doubt in using optical cable for video signalsCode:. ______| |Video1 VGA_to_Optic====fiber_glass====Optic_to_VGA| LCD1 | ______230V ---------- 230V ---------------------------|______| | |Video2 VGA_to_Optic==========fiber_glass=======Optic_to_VGA| LCD2 | ______230V ---------- 230V ------------------------------------|______| | |Video3 VGA_to_Optic================fiber_glass==========Optic_to_VGA| LCD3 |230V ---------- 230V ---------------------------------------------|______|230v ---------- 230v --------------------\|---------------------/ \| |MotorL MotorRQuote from: Ian.M on June 08, 2022, 09:38:36 amI have no crimping tools. Umm, I might buy some

author: DiTBho
author_rank: Super Contributor
timestamp: June 08, 2022, 11:56:03 am
content: Code:. ______| |Video1 VGA_to_udp/ip=====100BaseT====udp/ip_to_VGA| LCD1 | ______230V ---------- 230V ---------------------------|______| | |Video2 VGA_to_udp/ip===========100BaseT=======udp/ip_to_VGA| LCD2 | ______230V ---------- 230V ------------------------------------|______| | |Video3 VGA_to_udp/ip=================100BaseT==========udp/ip_to_VGA| LCD3 |230V ---------- 230V ---------------------------------------------|______|230v ---------- 230v --------------------\|---------------------/ \| |MotorL MotorRVGA_to_udp/ip: grab VGA @ 30fps, H264 encode, transmit(udp/ip)udp/ip_to_VGA: receive(udp/ip), H264 decode, shot VGA @ 30fpsThis would also be interesting, it uses 100BaseT(copper) instead of 100BaseSX (optic).I cannot find decent products.I will try with "Baluns", first.

author: Ian.M
author_rank: Super Contributor
timestamp: June 08, 2022, 12:20:15 pm
content: Could you get three VGA cables through the conduit if you only had one power cable through it? If so, split the power top-side!

author: DiTBho
author_rank: Super Contributor
timestamp: June 08, 2022, 01:47:41 pm
content: Quote from: Ian.M on June 08, 2022, 12:20:15 pmUnfortunately no

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 09, 2022, 02:41:25 am
content: How about convert the VGA to HDMI and then use HDMI over CAT6 adapters?

author: Berni
author_rank: Super Contributor
timestamp: June 09, 2022, 05:23:53 am
content: Quote from: NiHaoMike on June 09, 2022, 02:41:25 amYep convert it to HDMI and send that trough Ethernet cables. It works pretty well and you don't get any extra input lag since the data is being converted and sent live.DisplayPort can also run multiple monitors over a single cable, but that would likely require the source to be a PC graphics card.

author: DiTBho
author_rank: Super Contributor
timestamp: June 09, 2022, 07:30:37 am
content: Quote from: NiHaoMike on June 09, 2022, 02:41:25 amIt's expensive.I have already tried several VGA-to-HDMI converters from Amazon, things like the GANUA are cheap 8-15 Euro but don't offer decent quality, the convert that actually does the job ... costs 110 euro, and a Couple of RX/TX HTMI-to-from-ethernet cost 120 euro.120 Euro RX/TX HDMI-to/from-ethernet110 Euro VGA-to-HDMI-----------------------------------------------------230 Euro per VGA lineFor qty=3, it will cost 690 Euro !!! crazy!!!

author: mariush
author_rank: Super Contributor
timestamp: June 09, 2022, 07:50:52 am
content: One of the things you could do is to modify the monitor's power supply to work on DC.If they're old monitors with pre-led (CCFL or whatever it's called) backlight, then the monitor will have a 230v to 12-20v power supply and from that voltage, there's gonna be 5v and 3.3v produced for the display board.The backlight will usually work with as little as 10v, and there's also universal CCFL driver boards on eBay that can work with 10v or more... but they usually make the monitor power supply output 12-20v to reuse it for headphone / speaker amplifiers as well.So basically what I'm trying to say is that you could hack the monitor to add a DC barrel jack connector and inject 12v...18v from a laptop adapter type of power supply directly AFTER the AC to DC conversion, and this would allow you to use much thinner DC power cables instead of 230v IEC standard (like on computer power supply) cables. Making room for other cables in that channel.As for other ideas, they make flat HDMI cableshttps://www.amazon.com/Flat-HDMI-Cable-20-Supports/dp/B074N6XFF7/and they also make flat ethernet cableshttps://www.amazon.com/Ethernet-Internet-Network-Computer-Connectors/dp/B00WD017BG/If those monitors have DVI in the back, you could use a passive 2-3$ HDMI-DVI to make the monitor accept HDMI cable and you could use HDMI ... and being digital, the signal should be less sensitive to noise. You could use a cheap vga to hdmi converter on the computer side if the signals are analogue in the first place.

author: DiTBho
author_rank: Super Contributor
timestamp: June 09, 2022, 08:40:34 am
content: Quote from: mariush on June 09, 2022, 07:50:52 amNice idea. I will think about this.Quote from: mariush on June 09, 2022, 07:50:52 amYup. I have just ordered a couple of flat Ethernet cables for testing.Quote from: mariush on June 09, 2022, 07:50:52 amYup, my three LCDs have { VGA, DVI-D, DP } ports. I have also already ordered DVD-D-to-HDMI adapters (8 euro for a couple - gold contacts - so they said, we will see).Here you mean: buy qty3 VGA-to-HDMI adapter (3x110 = 330 euro) and save half the money.Great idea!

author: Berni
author_rank: Super Contributor
timestamp: June 09, 2022, 08:54:08 am
content: Quote from: DiTBho on June 09, 2022, 08:40:34 amThen why ware you even using VGA on the monitor end? Especially if you care about image quality since it adds an extra digital to analog to digital conversion.Is there a way to also sidestep VGA on the video source side?

author: mariush
author_rank: Super Contributor
timestamp: June 09, 2022, 08:54:36 am
content: Quote from: DiTBho on June 09, 2022, 08:40:34 amNo, there's also cheap vga to hdmi converters ... never used them but they could be an option if it's a must :https://www.amazon.com/QGeeM-Converter-adaptador-Computer-Projector/dp/B083K83NNX/https://www.amazon.com/dp/B071SHJ1S3/Not sure about the quality of the image but I imagine it wouldn't be awful.

author: m k
author_rank: Super Contributor
timestamp: June 09, 2022, 12:05:53 pm
content: I was wondering how this VGA over 100M Ethernet is operating since VGA pixel rate is 18M and so bitrate is 440M for truecolor.Technically frame is not a picture so is it interlaced and so 15 packed pics/sec?Not exactly a movie quality and mouse update can be a problem.

author: DiTBho
author_rank: Super Contributor
timestamp: June 09, 2022, 12:34:07 pm
content: Quote from: Berni on June 09, 2022, 08:54:08 amBecause on the host side the video graphic is VGA.

author: DiTBho
author_rank: Super Contributor
timestamp: June 09, 2022, 12:38:02 pm
content: Converting VGA (host) to HDMI (LCD) is an option (via DVI-D-to-HDMI), but it's not cheap: I have tried a lot of converters, the only VGA-to-HDMI that actually does the job costs 110 euro.I am considering this solution, anyway. Not cheap, but with flat-HDMI cables it looks an achievable sub-optimal one.

author: mariush
author_rank: Super Contributor
timestamp: June 09, 2022, 12:54:37 pm
content: Wouldn't it be cheaper to add a video card in the system, with 2-3 digital outputs?and i find it hard to believe you found no reliable vga to dvi/hdmi converter.. did you try products like the ones I linked to a few posts above?

author: DiTBho
author_rank: Super Contributor
timestamp: June 09, 2022, 04:32:58 pm
content: Quote from: mariush on June 09, 2022, 08:54:36 amYou never used, so WHY do you suggest random things?I have already tested many with no decent result with chap converters.

author: DiTBho
author_rank: Super Contributor
timestamp: June 09, 2022, 04:33:50 pm
content: Quote from: mariush on June 09, 2022, 12:54:37 pmOff course, I cannot!

author: DiTBho
author_rank: Super Contributor
timestamp: June 09, 2022, 04:36:16 pm
content: Solved. I contacted a company and bought three second hand VGA-to/from-optic units, 60 euro each.Not bad. Plus 40 euro for SC-SC optic cables