sdi

3 Articles

Arduino Does SDI Video With FPGA Help

February 6, 2023 by 12 Comments

If you are running video around your home theater, you probably use HDMI. If you are running it in a professional studio, however, you are probably using SDI, Serial Digital Interface. [Chris Brown] looks at SDI and shows a cheap SDI signal generator for an Arduino.

On the face of it, SDI isn’t that hard. In fact, [Chris] calls it “dead simple.” The problem is the bit rate which can be as high as 1.485 Gbps for the HD-SDI standard. Even for a super fast processor, this is a bit much, so [Chris] turned to the Arduino MKR Vidor 4000. Why? Because it has an FPGA onboard. Alas, the FPGA can’t do more than about 200 MHz, but that’s fast enough to drive an external Semtech GS296t2 serializer which is made to drive SDI signals.

The resulting project contains the Arduino, the serializer, a custom PCB, and both FPGA and microcontroller code. While the total cost of the project was a little under $200, that’s still better than the $350 to $2000 for a commercial SDI signal generator.

If you want to play along, the files are out on GitHub. We used the Vidor back in 2018 when it first came out. If you need a quick start on FPGAs, there’s always our boot camp.

Updating The Language Of SPI Pin Labels To Remove Casual References To Slavery

June 29, 2020 by 288 Comments

This morning the Open Source Hardware Association (OSHWA) announced a resolution for changing the way SPI (Serial Peripheral Interface) pins are labelled on hardware and in datasheets. The protocol originally included MOSI/MISO references that stand for “Master Out, Slave In” and “Master In, Slave Out”. Some companies and individuals have stopped using these terms over the years, but an effort is being taken up to affect widespread change, lead by Nathan Seidle of Sparkfun.

The new language for SPI pin labeling recommends the use of SDO/SDI (Serial Data Out/In) for single-role hardware, and COPI/CIPO for “Controller Out, Peripheral In” and “Controller In, Peripheral Out” for devices that can be either the controller or the peripheral. The change also updates the “SS” (Slave Select) pin to use “CS” (Chip Select).

SPI is widely used in embedded system design and appears in a huge range of devices, with the pin labels published numerous times in everything from datasheets and application notes to written and video tutorials posted online. Changing the labels removes unnecessary references to slavery without affecting the technology itself. This move makes embedded engineering more inclusive, an ideal that’s easy to get behind.

[2022 Editor’s Note: The OSHWA changed its recommended naming to PICO/POCI for “Peripheral In, Controller Out” and “Peripheral Out, Controller In”. Fine by us! I’ve updated this throughout the rest of the article because it doesn’t change Mike’s original argument at all.]

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Gimbal SDI Camera Mod

June 4, 2017 by 4 Comments

Sometimes when you need something, there is a cheap and easily obtainable product that almost fits the bill. Keyword: almost. [Micah Elizabeth Scott], also known as [scanlime], is creating a hovering camera to follow her cat around, and her Feiyu Mini3D 3-axis brushless gimbal almost did everything she’d need. After a few modifications, [Micah] now has a small and inexpensive 3-axis gimbal with a Crazyfire HZ-100P SDI camera and LIDAR-Lite distance sensor.

At thirty minutes long, [Micah’s] documenting video is rife with learning moments. We’ve said it before, and we’ll say it again: “just watch it and thank us later.” [Micah Elizabeth Scott] has a way of taking complicated concepts and processes and explaining things in a way that just makes sense (case in point: side-channel glitching) . And, while this hack isn’t exactly the most abstractly challenging, [Micah’s] natural talent as a teacher still comes through. She takes you through what goes right and what goes wrong, making sure to explain why things are wrong, and how she develops a solution.

Throughout her video, [Micah] shares small bits of wisdom gained from first-hand experience. From black hot glue to t-glase (a 3D printing filament), we learned of a few materials that could be mighty useful.

We’re no strangers to the work of [Micah Elizabeth Scott], she’s been on the scene for a while now. She’s been a Hackaday Prize Judge in 2015 and 2016 and is always making things we love to cover. She’s one of our three favorite hackers and has a beautiful website that showcases her past work.

Video after the break.

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