Chris Brown's Arduino MKR Vidor 4000 Carrier Is "Possibly the World's Cheapest SDI Signal Generator"

Designed as a test device for Serial Digital Interface (SDI) circuits, this FPGA-powered gadget pushes signals at 1.485Gbps.

Chris Brown, of sports media technology firm Tempus Ex, has designed "possibly the world's cheapest SDI signal generator" — based on an Arduino MKR Vidor 4000.

"In the world of professional video, SDI (Serial Digital Interface) is the industry standard for getting video from point A to point B," Brown explains by way of background. "It's the professional's equivalent of HDMI for consumer electronics. At any large-scale, televised event, you can bet that somewhere behind the scenes, there's a rat's nest where all of the video comes together and is distributed via SDI."

This carrier board for the Arduino MKR Video 4000 may be the cheapest SDI signal generator around. (📷: Chris Brown)

As you might expect from something aimed at professionals, SDI hardware is typically priced towards the upper end of the market — but, Brown points out, while SDI can offer high bitrates, the standard itself is relatively simple. To prove it, he's designed a low-cost SDI signal generator — which he describes as "the 'hello world'" of SDI hardware.

"To keep it simple, we'll just make the signal some flashing colors. And we'll aim to make this a 1080p30 signal, which can be transmitted via HD-SDI," Brown writes. "In theory, we just need to program a microcontroller that can send a 1.485Gbps signal to a cable driver. This would work if we could get our hands on such a microcontroller, but 1.485Gbps is quite fast. To be able to generate a signal at that speed, we'll need an FPGA, which can be programmed using a lower-level hardware description language to perform much faster operations."

The Arduino MKR Vidor 4000, handily, has both a microcontroller and an Intel Cylone 10 FPGA — just what the project needs. While its performance sits somewhere below the level required for nearly 1.5Gbps of data throughput, a Semtech GS2962 serializer finishes the build — in which ten data lines, each delivering 148.5Mbps, are run in parallel to hit the performance level required.

The project uses 10 parallel FPGA pins into a serializer to hit its impressively high bandwidth. (📷: Chris Brown)

"As far as I know," Brown writes, "this is the first time an Arduino has been capable of generating and emitting arbitrary SDI video signals, and as far as I know, this is also the cheapest SDI signal generator available anywhere. SDI signal generators typically cost anywhere from $350 to $2,000. This one costs ~$87 for the Arduino and ~$95 for the transmitter parts and assembly at low volumes. Although I don't recommend using an Arduino like this in mission critical workflows, it can be a valuable tool in the lab."

Brown's full write-up is available on the Tempus Ex blog, while the design files and source code are available on GitHub under an unspecified open-source license.

ghalfacree

Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire: freelance@halfacree.co.uk.

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