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Headless Ghost is a 4K display emulator (dummy plug) that fits discreetly in to a HDMI socket.
Headless Ghost is a 4K display emulator (dummy plug) that fits discreetly in to a HDMI socket.
545 backers pledged £8,157 to help bring this project to life.

PCBs, Delivery & DisplayPort

Posted by Dev Joshi (Creator)

It has been a busy week here at Headless Ghost HQ - let's round up what has been happening behind the scenes. 

DisplayPort adapter testing

I got a lot of emails about DisplayPort this week. Lots of people would like to see a DP version of the Headless Ghost and/or have been asking if the modules work with DisplayPort outputs using an adapter. 

The short answer is, "yes, for the most part." Stick with me...

DisplayPort and HDMI are fundamentally different technologies and as such their interoperability varies with the specific implementation of that technology on a particular device. There are also different versions of both DisplayPort and HDMI in common circulation which further complicates the issue. Attaching a Headless Ghost to a DisplayPort socket with an adapter will work but all of the resolutions present in the Headless Ghost memory may not be available. The resolutions which are available will be determined by the type of adapter that you use.

Some DisplayPort adapters are active and some are passive, some support HDMI 1.3 and others HDMI 1.4. As per my current test results, a passive adapter doesn't allow access to some of the higher resolutions stored in the Headless Ghost. Active adapters will allow you to simulate a 4K display, but only if the adapter is HDMI 1.4 compliant. There are some DisplayPort outputs in the world which are dual mode and actually natively support HDMI which means you don't need an active adapter. The number permutations of adapter, port type and working outputs are more numerous than I can realistically test for.

DVI and MiniHDMI adapters don't suffer from this issue because the adapters aren't doing anything clever; those technologies all come from a common linage. 

A native Headless Ghost for DisplayPort is possible, but to get it working reliably will take more time and testing than is reasonable to fit within the scope of a stretch goal so for now I'm not going to push it. Naturally, if I figure out a way to get it done, I'll make it available.

TL:DR - Headless Ghost at 4K is great when attached to a HDMI port, when using a DisplayPort adapter your mileage may vary but it will work for the most part.

Any questions, drop me a message and I'll try and answer them.

Production & delivery

The production machine for Headless Ghost has been gearing up this week as I have been talking with contract manufactures and supply chain people. 

With more than half of the campaign still left to run, there are almost twice as many orders than I had originally anticipated. Bigger order quantiles mean adjustments need to be made to the production pipeline so that the modules can still be made in a timely way all the while keeping build quality as high as I would like. 

More backers means that there are more modules to move around, package up and ship to you guys. While I had originally planned to have to have a 'postage, packaging and pizza' party with my friends the fulfilment of rewards to you is now being dealt with by a specialist firm. 


Not all circuit boards are created equal. Given that the Headless Ghost modules are mostly made of circuit board, I've been paying particular attention to the way they are being produced. PCBs come in a wide variety of colours and finishes - here are some examples that I had on my desk:

Clockwise from top left: A blue Arduino, matte black and gloss black sample boards, a red XTAG debug interface and a  green component reference board
Clockwise from top left: A blue Arduino, matte black and gloss black sample boards, a red XTAG debug interface and a green component reference board

All of the images of the Headless Ghost you have seen so far are of green circuit boards from my prototyping service. The production units will be made on circuit boards that have a super sexy matte black finish and gold (ENIG) plating on the exposed metal pads. Something like this:

The gold helps to prevent corrosion and tarnishing on the exposed parts of the modules. 

Further updates from the front lines of manufacturing are forth coming but that's all for now folks. Thanks again for your continued support.

Best regards from rainy London,


Norah Lewis, Walter Kuntner, and 2 more people like this update.


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    1. Missing avatar

      edzieba on

      For clarification of DisplyaPort:

      If you DisplayPort is labelled as "DP++", then it can both act as a native DisplayPort output, OR as a just-happens-to-be-DP-shaped HDMI (or single-link DVI) output. This allows for use with a passive adapter that literally just rearranges the pins so you can plug in a HDMI cable. The Headless Ghost will work just as if it were plugged into a HDMI port.

      If your DisplayPort is labelled just as 'DP', then it can only output DisplayPort. An active adapter (that converts from DisplayPort's packetised data stream to the linear pixel stream of HDMI and DP) will be needed.

      With the active adapter, you're limited by how the adapter implements EDID, which will likely be that it generates its own EDID describing what its internal converter can handle, possibly after polling the device plugged into the adapter and then announcing only timings the two have in common.