When it comes to high-performance desktop PCs, particularly in the world of gaming, water cooling is popular and effective. However, in the world of datacenters, servers rely on traditional air cooling more often than not, in combination with huge AC systems that keep server rooms at the appropriate temperature.
However, datacenters can use water cooling, too! It just doesn’t always look quite how you’d expect.
Continue reading “The Weird World Of Liquid Cooling For Datacenters”
While low-contrast, blue-on-slightly-less-blue 16-character by 2-line LCDs are extremely popular, they really are made specifically for alphanumeric use. They do an admirable job of displaying a few characters, but they don’t exactly spring to mind as a display for non-character purposes. But displaying video on a 16×2 LCD is possible, as long as you’re willing to stretch the definition of “video” a bit and use some imagination while watching.
Normally, a 16×2 display can only display a single character in each spot, chosen from a fixed character set. But [arduinocelantano] was able to leverage the eight custom character slots the display allows to build up images from arbitrary 5×8 pixel bitmaps. After using ffmpeg to scale the original video to a viewport of eight characters, a Python program was used to turn every frame of the scaled video into code to generate the custom bitmaps for each chunk of the viewport. Even with the low refresh rate of the display and the shrunken frame size, the result is a recognizable video, helped no doubt by the choice of the shadow-puppet Bad Apple!! video. Check it out after the break to see how it looks.
We saw a similar rendering of the same video on LCD a while back; that effort was amazing in that it was an EEPROM-only implementation, along with a somewhat bigger LCD with better contrast. That project served as inspiration for [arduinocelantano]’s build here, which in some ways we think looks a bit better — perhaps it’s the inverted pixels. Either way, hats off to both builders for pushing past the normal constraints and teaching us something interesting.
Continue reading “Pushing The Limits Of A 16×2 LCD With Bad Apple!!“
If you’ve ever spent time watching the goings-on at a seaport, you must have seen tugboats at work: those little boats that push, pull and nudge enormous cargo ships through tight corners in the harbor. They manage to do that thanks to hugely powerful engines sitting inside their relatively small hulls; their power-to-tonnage ratio can be ten times that of most commercial ships.
One hardware hacker who enjoys building similarly-overpowered machinery is [Luis Marx], and it might not come as a surprise that his latest project is an actual tugboat. Living on the shores of Lake Constance in southern Germany, [Luis] likes to spend time on the water, but got fed up with the chore of paddling. Local regulations restrict the use of outboard motors but allow the use of R/C model boats; therefore, building an R/C tugboat to move yourself around the lake should be perfectly legal.
While we’re not sure if the Lake Constance Police will follow the same reasoning, [Luis]’s model tugboat is a wonderful piece of engineering. With a design inspired by 3DBenchy, the standard 3D printer benchmark that probably anyone with a 3D printer has printed at some point, it took about 30 hours to create the parts plus a generous helping of epoxy resin to make it all waterproof. A beefy lithium-ion battery pack drives two brush-less DC motors designed for racing drones, which together can put out nearly one kilowatt of power.
That, unfortunately, turned out to be way more than the little boat could handle: any attempt at using it simply caused it to leap out of the water and land on its back. Setting the motor controller to around 50% made it much more controllable, yet still strong enough to move [Luis] around on his standup paddle board. The boat is controlled through a custom-made handheld R/C controller that communicates with the ESP8266 inside the boat through WiFi. With no rudder, left-right control is effected by simply reducing the power of one motor by half.
A fully-charged battery pack provides enough juice for about 40 minutes of tugging, so it’s probably a good idea to bring along paddles in any case. Unless, of course, you’ve also got a solar-powered autonomous tugboat ready to come to your rescue.
