i.mx

2 Articles

SLR To DSLR Conversion Becomes Full Camera

August 22, 2023 by 8 Comments

At least as far as the inner workings are concerned, there’s not a whole lot of difference between an single-lens reflex (SLR) camera that uses film and a digital SLR (DSLR) camera that uses an electronic sensor except the method for capturing the image. So adding the digital image sensor to a formerly analog camera like this seemed like an interesting project for [Wenting Zhang]. But this camera ballooned a little further than that as he found himself instead building a complete, full-frame digital camera nearly from scratch.

The camera uses a full-frame design and even though the project originally began around the SLR mechanism, in the end [Wenting] decided not to keep this complex system in place. Instead, to keep the design simple and more accessible a mirrorless design is used with an electronic viewfinder system. It’s also passive M lens mount, meaning that plenty of manual lenses will be available for this camera without having to completely re-invent the wheel.

As far as the sensor goes, [Wenting] wanted something relatively user-friendly with datasheets available so he turned to industrial cameras to find something suitable, settling on a Kodak charge-coupled device (CCD) for the sensor paired with an i.MX processor. All of the electronics have publicly-available datasheets which is important for this open-source design. There’s a lot more work that went into this build than just picking parts and 3D printing a case, though, and we’d definitely recommend anyone interested to check out the video below for how this was all done. And, for those who want to go back to the beginnings of this project and take a different path, it’s definitely possible to convert an analog SLR to a digital one.

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How Many LEDs Can You Drive?

February 18, 2020 by 35 Comments

Driving more than a handful of LEDs from a microcontroller is often a feat that takes tedious wiring, tricking the processor, or a lot of extra external hardware. Charlieplexing is perhaps the most notorious of these methods, and checks two of those three boxes. This library for the Teensy 4.0 checks all three, but it can also drive a truly staggering 32,000 LEDs at one time.

The TriantaduoWS2811 library is able to drive 32 channels of LEDs from a Teensy 4.0 using only three pins and minimal processor resources. It uses the FlexIO and DMA subsystems of the i.MX RT1062, the particular ARM processor on the Teensy, to drive four external shift registers. Together, the system is able to achieve 30 frames per second on with 1,000 LEDs per channel, for a total of 32,000 LEDs. Whoah.

[Ward] aka [wramsdell] wondered what one would do with all of the horsepower of a Teensy microcontroller when he first saw its specifications, and was able to build this project to take advantage of its features. What’s surprising, though, is that it doesn’t use nearly everything the processor is capable of, so you can do other tasks at the same time as driving that giant LED display.