Inspired by battle-hardened military robots, [Engineering Juice] wanted to build his own remote controlled rover that could deliver live video from the front lines. But rather than use an off-the-shelf tracked robot chassis, he decided to design and 3D print the whole thing from scratch. While the final product might not be bullet proof, it certainly doesn’t seem to have any trouble traveling through sand and other rough terrain.
Certainly the most impressive aspect of this project is the roller chain track and suspension system, which consists of more than 200 individual printed parts, fasteners, bearings, and linkages. Initially, [Engineering Juice] came up with a less complex suspension system for the robot, but unfortunately it had a tendency to bind up during testing. However the new and improved design, which uses four articulated wheels on each side, provides an impressive balance between speed and off-road capability.
Internally there’s a Raspberry Pi 4 paired with an L298 dual H-bridge controller board to drive the heavy duty gear motors. While the Pi is running off of a standard USB power bank, the drive motors are supplied by a custom 18650 battery pack utilizing a 3D printed frame to protect and secure the cells. A commercial night vision camera solution that connects to the Pi’s CSI header is mounted in the front, with live video being broadcast back to the operator over WiFi.
[Russell Graves] lives in Idaho and recently connected his solar installation to the grid, which meant adhering to regulatory requirements for both the National Electric Code (NEC) as well as complying with the local power company’s own regulations. His blog post is an interesting look at the whole regulatory process and experience, and is of interest to anyone curious about running their own solar farm, whether they have plans to connect it to the grid or not.
The power company has a very different set of priorities from the NEC, and part of [Russell]’s experience was in having to meet requirements that weren’t documented in the expected places, so study of the materials didn’t cut it. In particular, the power company needed the system to have disconnects with conductors that visually move out of position when disconnected. [Russell] was using NEC-compliant circuit breakers that met NEC code, but they didn’t meet the power company requirement for conductors that can be visually confirmed as being physically disconnected. Facing a deadline, [Russell] managed to finesse a compliant system that was approved, and everything got signed off just as winter hit.
How well does his solar farm work out? Sometimes the panels produce a lot of power, sometimes nearly nothing, but it has been up and running for all of winter and into spring. Over the winter, [Russell] pulled a total of 3.1 MWh from the grid, mainly because his home is heated with electric power. But once spring hit, he started pushing considerably more into the grid than he was pulling; on some days his setup produces around 95 kWh, of which about 70 kWh gets exported.
We’re always fans of interesting clock builds around here, whether it’s a word clock, marble clock, or in this case a clock using a unique display method. Of course, since this is a build by Hackaday’s own [Moritz v. Sivers] the display that was chosen for this build was a custom thermochromic display. These displays use heat-sensitive material to change color, and his latest build leverages that into one of the more colorful clock builds we’ve seen.
The clock’s display is built around a piece of thermochromic film encased in clear acrylic. The way the film operates is based on an LCD display, but using heat to display the segments. For this build, as opposed to his previous builds using larger displays, he needed to refine the method he used for generating the heat required for the color change. For that he swapped out the Peltier devices for surface mount resistors and completely redesigned the drivers and the PCBs around this new method.
Of course, the actual clock mechanism is worth a mention as well. The device uses an ESP8266 board to handle the operation of the clock, and it is able to use its wireless capabilities to get the current time via NTP. All of the files needed to recreate this are available on the project page as well, including code, CAD files, and PCB layouts. It’s always good to have an interesting clock around your home, but if you’re not a fan of electronic clocks like this we can recommend any number of mechanical clocks as well.
The battery and its associated support circuitry is a mite unconventional in its design, but it gets the job done. The build uses two lithium polymer pouch cells in place of the original four cell sealed-lead acid battery, to replicate the roughly 7.2V nominal voltage. Because of this, unfortunately the stock PowerBook charger can’t provide enough voltage to fully charge the LiPo cells up to their full 8.4 volts.
The workaround selected is that when the batteries fall below 80% state of charge, relays disconnect the cells from their series configuration powering the laptop, and instead connect each cell to its own single-cell charger board. Once charging is complete, the relays switch back out of charging mode so the batteries power the laptop once more. The only major drawback is that withdrawing the power adapter while the batteries are on charge will cut all power to the laptop.
It may not be perfect, but [360alaska] has succeeded in building a drop-in battery solution for the PowerBook 100 that can be used with the stock charger. Laptop batteries can be a fraught thing to deal with; often there are safeguards or DRM-type issues to navigate to get them to work around. Sometimes open-source designs are the best solution out there.
1985 saw the release of the Casio SK-1, a compact sampling keyboard that brought the technology to a lower price point than ever before. However, one drawback of this was that it comes stock with only a 2.5 octave keyboard. [Jonas Karlsson] wanted a little more range out of the instrument, so set about hacking in his own octave mod.
The build consists of fiddling with the SK-1’s microprocessor clock to change the pitch of the notes generated by the instrument. The original clock is generated by a simple LC circuit, which in this mod is fed to an inverter, and then a pair of flip-flops to divide the clock by four. The original clock and the divided version are then both sent to a mux chip. With the flick of the switch, either the original or downshifted clock can be sent to the microprocessor.
With the slower clock feeding the microprocessor, all the notes are downshifted an octave. The resulting sound, which you can listen to on Soundcloud, is similar to what you get when chopping down sample rates. It bears noting, however, that as this mod changes the master clock, other features such as rhythms are also effected.
Land speed racing is one of the oldest forms of motorsport, and quite literally consists of going very, very fast in (ideally) a straight line. The higher the speed your car can attain, the better! It’s about the pure pursuit of top speed above all else, and building a car to compete is a calling for a dedicated few. If you’d like to join them, here’s how to go about it.
Racers often pick a record or set of records they wish to beat – for example, wanting to set the the fastest speed for a gasoline-powered, naturally-aspirated four cylinder – and build their car to that end. Alternatively, a racer might build a car with a large V8 engine, for example, to compete in one class, and then disable several cylinders on a later run to try and snatch records in lower classes as well. Continue reading “How To Get Into Cars: Land Speed Racing”→
The result is a gloriously colorful keyboard and controller set up to work with a PC. The stock membrane keyboard was removed entirely, which is possible without interfering with the gamepad hardware inside the controller shell. It was replaced with a Preonic keyboard PCB, fitted with Lubed Glorious Panda switches and those wonderful pastel DSA Vilebloom keycaps. The keyboard also features a Durock screw-in stabilizer to make sure the space key has a nice smooth action. The controller itself received a set of colored buttons to match the theme, setting off the aesthetic. It’s still fully functional, and can be used with an adapter to play games on the attached PC.
Overall, it’s a tidy controller casemod and one hell of a conversation starter when the crew are scoping out your battlestation. The added weight might make it a little straining for long gaming sessions in controller mode, but it looks so pretty we’re sure we wouldn’t notice.