Around here we love technology for its own sake. But we have to admit, most people are interested in applications–what can the technology do? Those people often have the best projects. After all, there’s only so many blinking LED projects you can look at before you want something more.
[Landingfield] is interested in astrophotography. He was dismayed at the cost of commercial camera sensors suitable for work like this, so he decided he would create his own. Although he started thinking about it a few years ago, he started earnestly in early 2016.
The project uses a Nikon sensor and a Xilinx Zynq CPU/FPGA. The idea is the set up and control the CMOS sensor with the CPU side of the Zynq chip, then receive and process the data from the sensor using the FPGA side before dumping it into memory and letting the CPU take over again. The project stalled for a bit due to a bug in the vendor’s tools. The posts describe the problem which might be handy if you are doing something similar. There’s still work to go, but the device has taken images that should appear on the same blog soon.
Industrial hardware needs to be reliable, tough, and interoperable. For this reason, there are a series of standards used for command & control connections between equipment. One of the more widespread standards is ModBus, an open protocol using a master-slave architecture, usually delivered over RS-485 serial. It’s readily found being used with PLCs, HMIs, VFDs, and all manner of other industrial equipment that comes with a TLA (three letter acronym).
[Absolutelyautomation] decided to leverage ModBus to control garden variety digital cameras, of the type found cluttering up drawers now that smartphones have come so far. This involves getting old-school, by simply soldering wires to the buttons of the camera, and using an Arduino Nano to control the camera while talking to the ModBus network.
This system could prove handy for integrating a camera into an industrial production process to monitor for faults or defective parts. The article demonstrates simple control of the camera with off-the-shelf commercial PLC hardware. Generally, industrial cameras are very expensive, so this hack may be useful where there isn’t the budget for a proper solution. Will it stand up to industrial conditions for 10 years without missing a beat? No, but it could definitely save the day in the short term for a throwaway price. One shortfall is that the camera as installed will only save pictures to its local memory card. There’s a lot to be said for serving the images right to the engineer’s desk over a network.
Digital cameras are great, because you can take thousands of pictures without running out of film. But there’s something to be said for having a tangible image you can hold in your hand. The Polaroid cameras of yesteryear were great for this, but now they’re hard to find and the price per photograph is ludicrously expensive.
Over the past few years, a few people have sought a way to create printed photographs at a lower cost. One of the best ways to do this is to find something much cheaper than Polaroid film — like thermal paper.
[Fabien-Chouteau]’s thermal printing camera isn’t the first — you’ve got the Gameboy Camera/Printer and a few others to thank for that. But it’s a great example of the form. The camera combines an Adafruit thermal receipt printer with an OpenMV camera, both easily sourced, if not exactly cheap. It even adds a ST7735 LCD for live display of the camera’s image, just like consumer-grade cameras!
It’s not just a slapped together kludge of parts bin components, however. While the thermal printer is only capable of printing black or white pixels, its resolution is much higher than the image from the camera. This allows the camera to use a 3×3 block of printed pixels to represent a single pixel from the camera, and with some fancy dithering techniques, can emulate shades of grey quite effectively. It’s tricks like this that really add polish to a project, and make a big difference to the picture quality at the end of the day.
It’s not the first thermal printer camera we’ve seen – [Ch00f]’s woodgrain instant camera build highlighted the issues of careful camera selection when pursuing this type of build.
The Raspberry Pi Camera is a great tool; it allows projects that require a camera to be put together quickly and on a budget. Plus, having a Linux back end for a little processing never hurt anybody. What can be difficult however, is imaging in low light conditions. Most smartphones have an LED flash built in for this purpose. [Wim Van Gool] decided to follow suit and build an LED flash for the Raspberry Pi.
The project consists of a custom PCB with surface-mount LEDs in an attractive concentric layout. This is a good way to get a nice even distribution of light, particularly when taking photos close up. The board is designed around the Texas Instruments TPS61169 LED driver, which is controlled by a PWM signal from the Raspberry Pi. The flash mounts as a Raspberry Pi HAT, and there’s a hole routed in the centre to allow the camera to fit in nice and snug when using standard 11mm standoffs. It might seem simple, but it’s an impressively tidy piece of engineering and a testament to [Wim]’s abilities.
Think you need some fancy equipment to get stunning shots of the night sky? Surely those long-exposure shots that show the Milky Way in all its glory take expensive telescopes with complicated motor-driven equatorial mounts, right? Guess again – you can slap together this simple barn door tracker for a DSLR for a couple of bucks and by wowing people with your astrophotography prowess tonight.
Those stunning, deeply saturated shots of our galaxy require a way to cancel out the Earth’s movement, lest star trails ruin your long exposure shots. Enter the barn door tracker, a simple device to let you counter the Earth’s rotation. [benrules2]’s version of the tool is ridiculously simple – two boards connected by a hinge. A short length of threaded rod with a large handle passes through a captive nut in the upper board.
A little trig allows you to calculate how much and how often to turn the handle (by hand!) to counter the planet’s 0.25°/minute diurnal rotation. Surprisingly, the long exposure times seem to even out any jostling introduced by handling the rig, but we’d still imagine a light touch and a sturdy tripod would be best. Those of you with less patience might automate this procedure.
It seems a lot to ask of a rig that you could probably throw together in an hour from scrap, but you can’t argue with [benrules2]’s results. His isn’t the only barn door tracker we’ve covered, but it looks like the simplest by far and would be a great project to build with kids.
Untold miles of film were shot by amateur filmmakers in the days before YouTube, iPhones, and even the lowly VHS camcorder. A lot of that footage remains to be discovered in attics and on the top shelves of closets, and when you find that trove of precious family memories, you’ll be glad to have this Raspberry Pi enabled frame-by-frame film digitizer at your disposal.
With a spare Super 8mm projector and a Raspberry Pi sitting around, [Joe Herman] figured he had the makings of a good way to preserve his grandfather’s old films. The secret of high-quality film transfers is a frame-by-frame capture, so [Joe] set about a thorough gutting of the projector. The original motor was scrapped in favor of one with better speed control, a magnet and reed switch were added to the driveshaft to synchronize exposures with each frame, and the optics were reversed with the Pi’s camera mounted internally and the LED light source on the outside. To deal with the high dynamic range of the source material, [Joe] wrote Python scripts to capture each frame at multiple exposures and combine the images with OpenCV. Everything is stitched together later with FFmpeg, and the results are pretty stunning if the video below is any indication.
We saw a similar frame-by-frame grabber build a few years ago, but [Joe]’s setup is nicely integrated into the old projector, and really seems to be doing the job — half a million frames of family history and counting.
[Robin] is a hobby photographer with some very nice old film camera gear. But who has the money or patience for developing film these days? (Well, lots of people, especially artists, but that’s a different Hackaday article.) So to update his old gear without breaking the bank, he glommed a Sony Nex digital camera onto the back of a nice old Nikon, and documented the process for us.
A friend of mine once said, “never underestimate what a good engineer can do with a file and patience.” [Robin]’s hack essentially consists of grinding the Sony’s CMOS sensor to fit exactly where the film plane would be in the old Nikon. For him, this meant relocating the IR filter glass, because it wouldn’t fit with the shutter, and then slowly and accurately trimming down the edges of the CMOS sensor’s retaining frame until it was just right.