HDMI repeater - Page 1
Forum section: electronics / beginners

author: fxr
author_rank: Contributor
timestamp: August 03, 2020, 10:51:25 pm
content: Hello everyone!I need to make a very long (more 30 meters) connection for transmitting 4K video by HDMI cable.This big problem for me, because the maximal length of HDMI cable maybe around 15 meters.I think about to make a repeater of HDMI video signal.Please advise the video signal repeater circuit.

author: tooki
author_rank: Super Contributor
timestamp: August 03, 2020, 11:52:00 pm
content: Just buy an active repeater. There is absolutely no way you could build one cheaper than it can be bought, and a homemade one isn’t even likely to work well, as HDMI signals are extremely high frequency and require skill in advanced PCB design. (And the signal is so fast that you can’t use a regular oscilloscope to probe it to troubleshoot — you need a scope that costs as much as a luxury car.)

author: 0culus
author_rank: Super Contributor
timestamp: August 04, 2020, 12:05:57 am
content: Yeah...this firmly in the "just buy one and be done with it" category. Unless you already have expertise in this areaandhave access to some very high end test equipment, you won't be able to make one.Here's one, just under 20 Yankee bux:https://www.amazon.com/Repeater-Extender-Booster-Lossless-Transmission/dp/B01N0OISVS

author: fxr
author_rank: Contributor
timestamp: August 04, 2020, 12:52:44 am
content: Thanks for yours answers!You are right, buying a ready-made device is easier and cheaper.But, I want to build a custom solution, it is interested for me.Also I can get access for measurement equipment.I found recommendations for routing HDMI traces.https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/138/5706.Texas-Instruments-HDMI-Design-Guide.pdf

author: tooki
author_rank: Super Contributor
timestamp: August 04, 2020, 05:53:13 pm
content: This stuff falls well into the category of “if you have to ask for suggested circuits, the task is well beyond your skill level”. No offense intended, just emphasizing that this is an area where if you have to ask, you shouldn’t be doing it. It’s too advanced, and reading a white paper won’t solve that.I also suspect that if you had access to the caliber of test equipment that is needed for HDMI debugging, you wouldn’t need to ask questions.Just buy one.

author: RoadRunner
author_rank: Frequent Contributor
timestamp: August 04, 2020, 06:16:48 pm
content: Making stuff yourself is either to Earn or Learn or for fun. As pointed out by other, there nothing to earn here.And when it come to learning, Skill you may gain by making your own HDMI repeater, There are other projects which will have better learning curves.When it comes to fun, One can certainly have lots of fun making HDMI repeater.

author: fxr
author_rank: Contributor
timestamp: August 04, 2020, 11:11:04 pm
content: tookiI already bought one repeater.And you right, this project out of my skill level.RoadRunnerThis project not for earn.Anyway I want make this job.I found not bad solution based the specialized chip.I believe most of the work can be simulated by software.The required measurement equipment is not on my work bench.But I can go to a measuring laboratory and take measurements for little money.I would be grateful if in the process of designing the circuit you point out flaws.

author: free_electron
author_rank: Super Contributor
timestamp: August 04, 2020, 11:46:05 pm
content: You may not be able to get those chips and even if you do , the programming manual will be under NDA. Anything HDMI involves licensing ...

author: amyk
author_rank: Super Contributor
timestamp: August 05, 2020, 12:16:50 am
content: You shouldn't need to decode the signal, just amplify it, and I'm pretty sure there are single-chip solutions available. Finding one and copying the reference design exactly is probably your highest chance of success.

author: fxr
author_rank: Contributor
timestamp: August 05, 2020, 01:35:42 am
content: I want to use single-chip solutions without signal decode as saidamyk.I found this one TMDS181 from TI.Manufacturer also offer the developing board with complete schematic and layout.Main features:HDMI™ Input Port to Output Port With CDR Supporting Up to 6 Gbps Data RatesCompatible With HDMI™ Electrical Parameters Up to 6 Gbps in Retimer ModeSupport 4k2k60p and Up to WUXGA 16-Bit Color Depth or 1080p With Higher Refresh RatesRetimes Input Stream to Compensate for Random JitterAdaptive Receiver Equalizer or Programmable Fixed EqualizerI2C and Pin Strap ProgrammableInter-Pair Skew Compensation of 5+ BitsSingle-Ended Mode ARC SupportLink Debug Tools Including Eye Diagram After the RX Equalizer48-Pin 7-mm × 7-mm 0.5-mm Pitch VQFN PackageExtended Commercial Temperature Support 0°C to 85°C (TMDS181)Industrial Temperature Support: –40°C to 85°C (TMDS181I)