Hi all,
I have a very old raspberry pi (maybe version 1) running some software sucessfully.
It is a timer system for sporting competitions.
It outputs to multiple monitors via hdmi and a splitter cable. One side of the splitter runs a local monitor while the other sides heads off to a fibre optics system which again splits the hdmi and shoots is off over the cables to monitors approx 25 to 30 metress of cable distance away. This all works fine and has been in place for a number of years.
Recently went ot upgrade it to a Pi4 which i discovered uses micro hdmi so i bought an adaptor cable from amazon.
It worked well during my testing at home on a single monitor but once i use the splitter cable I think it gets some sort of signal degregation as I can see poor quality display on the local monitor and after a couple of minutes all the displays start flashing on and off.
Is this due to the micro hdmi suppling a signal that is not as strong a a normal hdmi or is the convertor cable more likely to be the culprit?
I’m over budget to do this upgrade for the club so any more parts I need are most likely going to have to come from my pocket.
I’d love to hear what people think. I could try another micro cable and run the monitors off different hdmi ports (there are 2 on the Pi4) or maybe i need a powered splitter to boost the hdmi signal?
thanks
Darren
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Hey @Darren130430,
I wouldn’t think this issue would be caused by the micro HDMI adapter or output from the Pi. Micro HDMI should have pretty similar specs to standard HDMI. Feel free to share a link to this adapter if you like for us to double-check.
It sounds like it may be something to do with the splitter cable or the output signal coming from the Pi.
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Hi Samuel, this is the adaptor I am using CY Micro HDMI Male to HDMI Female Cable Adapter,HDMI Female to Micro HDMI Male Cable for HDTV Camera 10CM : Amazon.com.au: Electronics. The only hardware difference in the system between existing and upgraded is this adapter and the actual PI.
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Hi @Darren130430, thanks for that link!
Hmmmm, I can’t see anything on that product page that would make me think that the cable is the problem.
Doing some digging, it seems like this could be an issue with what kind of monitors the Pi thinks it is connected to. Most displays will talk to the Pi and send it an EDID (Extended Display Identification Data), which lets the Pi know the display’s resolution and some other useful bits of information.
With multiple displays connected through a splitter, it could be possible that the Pi is getting confused about to type of output to give to multiple displays and has landed on a less than ideal output.
From what I can find online, adding the line hdmi_ignore_edid=0xa5000080 to the bottom of the config file on the Pi seems to help. You can find the config file on your Pi at /boot/firmware/config.txt
This line tells the Pi to ignore any EDID information it receives which may make a difference.
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