Axiom, A 100+kW Motor Controller For Making Big Motors Move

We’ve seen a lot of motor driver boards for robots and the odd electric skateboard. What we haven’t see a lot of is one big enough to drop into an electric vehicle. 

The Axiom motor controller was a winner of the bootstrap contest and is a Finalist in the 2019 Hackaday Prize. The driver aims to deliver 300A continuous at 400V all day long. Which is a very impressive amount of power from a board that appears to be quite compact.

The brains of the device is an ice40 FPGA from Lattice running software based on the VESC Project. Its open source roots will certainly allow for some interesting hacks and an increasingly stable platform over time. Not to mention the existing software tools will aid in the sometimes cumbersome motor-driver tuning process.

The board designs are available, but we agree with the team that the complexity of assembly is likely going to be high (along with the price). The amount of research and skill going into this complicated kit is a bit mind-boggling, but we hope it will really enable some cool hacks, from cars, to ATVs, and maybe even an electric flyer.

Ferrofluid Display Fuels The Fun, And The Procrastination

When deadlines loom and your future is on the line, do what top college students through the ages have always done: procrastinate! [Simen] and [Amund] did that in grand style by starting a YouTube channel, delightfully and aptly named “Applied Procrastination”, wherein they plan to avoid their responsibilities as long as possible in favor of making a large-scale ferrofluidic display panel. (Video, embedded below.)

We suppose we should encourage them to hit the books, but honestly they look like they’re having much more fun and learning more than they would in class. The idea isn’t new; we’ve seen ferrofluid clocks before, after all. [Amund] and [Simen] have grander plans for their display, but they’re wisely starting small with basic experiments. They had an early great idea to use a double-pane window as a tank for their display, but coatings on the inside of the glass and the aluminum frame conspired to cloud the display. They also did some tests to make sure they can control 252 electromagnets safely. They did manage to get a small test display working, but really the bulk of the video is just them playing with magnets and ferrofluid. And again, we’re OK with that.

It looks like this is going to be an interesting project, with hopefully regular updates to the channel now that summer break is upon us. Unless they find something else to do, of course.

Continue reading “Ferrofluid Display Fuels The Fun, And The Procrastination”

Test PCBs On A Bed Of Nails

While it might be tempting to start soldering a circuit together once the design looks good on paper, experience tells us that it’s still good to test it out on a breadboard first to make sure everything works properly. That might be where the process ends for one-off projects, but for large production runs you’re going to need to test all the PCBs after they’re built, too. While you would use a breadboard for prototyping, the platform you’re going to need for quality control is called a “bed of nails“.

This project comes to us by way of [Thom] who has been doing a large production run of circuits meant to drive nixie tubes. After the each board is completed, they are laid on top of a number of pins arranged to mate to various points on the PCB. Without needing to use alligator clamps or anything else labor-intensive to test, this simple jig with all the test points built-in means that each board can be laid on the bed and tested to ensure it works properly. The test bed looks like a bed of nails as well, hence the name.

There are other ways of testing PCBs after production, too, but if your board doesn’t involve any type of processing they might be hard to implement. Nixie tubes are mostly in the “analog” realm so this test setup works well for [Thom]’s needs.

The Complete Beginner’s Guide To Building A CNC Machine

Despite appearances, [This Old Tony]’s latest series has little to do with CNC-ifying an Etch A Sketch. Although he certainly achieves that, more or less, automating the classic toy is just the hook for a thorough lesson in CNC machine building starting with the basics.

Fair warning: we said basics, and we mean it. [Old Tony]’s intended audience is those who haven’t made the leap into a CNC build yet and need the big picture. Part one concentrates on the hardware involved – the steppers, drivers, and controller. He starts with one of those all-in-one eBay packages, although he did upgrade the motion controller to a Mach4 compatible board; still, the lessons should apply to most hardware.

By the end of part one, the Etch A Sketch is connected to two of the steppers and everything is wired up and ready to go for part two, the first part of which is all about inputs and outputs. Again, this is basic stuff, like how relays work and why you might need to use them. But that’s the kind of stuff that can baffle beginners and turn them off to the hobby, so kudos to [Old Tony] for the overview. The bulk of the second part is about configuring Mach4 Hobby, with a ton of detail and some great tips and tricks for getting a machine ready to break some end mills.

For someone looking to get into a CNC build, [Old Tony]’s hard-won CNC experience really fills in the gaps left by other tutorials. And it looks like a third part, dealing with making all this into something more than an automated Etch A Sketch, is in the works. We’re looking forward to that.

Continue reading “The Complete Beginner’s Guide To Building A CNC Machine”

A Guide For Driving LED Matrices

Building an LED matrix is a fun project, but it can be a bit of a pain. Usually it starts with hand-soldering individual LEDs and resistors together, then hooking them up to rows and columns so they can be driven by a microcontroller of some sort. That’s a lot of tedious work, but you can order an LED matrix pre-built to save some time and headache. You’ll still need a driver though, and while building one yourself can be rewarding there are many pitfalls and trade-offs to consider when undertaking that project as well. Or, you can consider one of a number of drivers that [deshipu] has outlined in detail.

The hangups surrounding the driver board generally revolve around the issue of getting constant brightness from LEDs regardless of how many in the row or column are illuminated at one time. Since they are typically driven one row or column at a time, the more that are on the lower the brightness each LED will have. Driver boards take different approaches to solving this problem, which usually involve a combination of high-speed scanning of the matrix or using a constant-current source in order to eliminate the need for resistors. [deshipu] outlines four popular chips that achieve these purposes, and he highlights their pros and cons to help anyone looking to build something like this.

Most of these boards will get you to an 8×8 LED matrix with no problem, with a few going a few pixels higher in either direction. That might be enough for most of our needs, but for something larger you’ll need other solutions like the one found in this 64×32 LED matrix clock. There are also even more complicated drivers if you go into extra dimensions.

Photo credit: Komatta [Public domain], from Wikimedia Commons

Make The Surface Dial Do More Things, Such As MIDI

The Surface Dial is a $100+ rotary control. You can turn it, and it’ll make some basic stuff happen on your Microsoft Surface. It’s silver and sleek and elegant but fundamentally, it just works via emulated keyboard shortcuts. This doesn’t really do much for translating analog rotational motion into digital feedback in a nice way, so [SaveTheHuman5] created Elephant to fix this issue.

As standard, there are two ways to work with the Surface Dial as an end-user. The easiest way is to use existing utilities to map dial actions to shortcut keys. However, for interfacing with knobs and sliders in user interfaces, this is clunky. Instead, [SaveTheHuman5] drilled down and created their own utility using the Surface Dial API provided by Microsoft. This allows raw data to be captured from the dial and processed into whatever interactions your heart desires – as long as you’ve got the coding muscles to do it!

The Elephant software allows the knob to be used in two distinct modes – mouse capture, and MIDI. Mouse capture allows one to use a regular mouse to select UI objects, such as knobs in a music application, and then turn the Surface Dial to adjust the control. Anyone that’s struggled with tiny emulated rotary controls on a VST synth before would instantly know the value of this. In MIDI mode, however, the knob simply presents itself as a MIDI device outputting commands directly which would be more useful in performance environments in particular.

Overall, it’s a tidy hack of an otherwise quite limited piece of hardware – the only thing we’d like to see is more detail on how it was done. If you’ve got a good idea on how this could work, throw it down in the comments. And, if your thirst for rotary controls is still not satiated, check out this media controller. Video after the break.

Continue reading “Make The Surface Dial Do More Things, Such As MIDI”

Custom LCD Module Is Unexpectedly Cheap And Easy

Looking to take your project to the next level in terms of functionality and appearance? A custom LCD display might be the thing that gets you there, at least compared to the dot-matrix or seven-segment displays that anyone and their uncle can buy from the usual sources for pennies. But how does one create such a thing, and what are the costs involved? As is so often the case these days, it’s simpler and cheaper than you think, and [Dave Jones] has a great primer on designing and specifying custom LCDs.

The video below is part of an ongoing series; a previous video covered the design process, turning the design into a spec, and choosing a manufacturer; another discussed the manufacturer’s design document approval and developing a test plan for the module. This one shows the testing plan in action on the insanely cheap modules – [Dave] was able to have a small run of five modules made up for only $138, which included $33 shipping. The display is for a custom power supply and has over 200 segments, including four numeric sections, a clock display, a bar graph, and custom icons for volts, amps, millijoules, and watt-hours. It’s a big piece of glass and the quality is remarkable for the price. It’s not perfect – [Dave] noted a group of segments on the same common lines that were a bit dimmer than the rest, but was able to work around it by tweaking the supply voltage a bit.

We’re amazed at how low the barrier to entry into custom electronics has become, and even if you don’t need a custom LCD, at these prices it’s tempting to order one just because you can. Of course, you can also build your own LCD display completely from scratch too.

Continue reading “Custom LCD Module Is Unexpectedly Cheap And Easy”