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The VM205 Oscilloscope and Logic Analyzer, Part 3

Virtual Machines.

Turns out I can emulate a raspberry pi in software using QEMU. QEMU is not for the faint of heart, because it’s all command line and you have to start on a Linux system. Should I have splurged for the UTM Mac app? Probably. But if you’re going to do this, here are useful links.
The doc is rotting, change the “buster”-specific stuff to a Bullseye install.

To get around the fact that libvert is fucked:

Still no joy.

After all that, it’s still no good, because the Versatile Board used in the emulation has a … Read the rest

The VM205 Oscilloscope and Logic Analyzer: Part 2

Getting it working.

TL;DR: I extended an API I found on GitHub to support the pigpio libraries.

This was an exercise in updating a C++ API to support a library now shipped with newer versions of the Raspberry Pi. As mentioned earlier, I found and forked a GitHub repo as a place to start.

That API supported a specific Broadcom chipset used on older Raspberry Pi boards, but I have a Pi 3B+ and a much newer 64bit OS, so I needed to go another way.

The pigpio libraries and dev libraries are available as Debian packages, so installing … Read the rest

VEX and Attribute Subscripts

So many things about Houdini can trip you up, then eat your face off while you’re down. Today’s example is the VEX dot operator. I haven’t ridden the VEX horse into battle in a very, very long time, and like any horse, if you’re not paying attention, it’ll do what it wants, not what you want.

I’m a visual person. I see stuff and make choices based on that. So what I see in Houdini’s Geometry Spreadsheet are columns with headers like this:

P[x]    P[y]     P[z]   direction[0] direction [1]  distance

P is a vector with 3 components. Any time you … Read the rest

Houdini HDA Python Module and You

I’m getting reacquainted with Houdini of late, and getting back to grips with Houdini Digital Assets.  these are encapsulated chunks of pipeline that support all manner of neat stuff, and they’re usually full of Python scripts that do interesting things with whatever’s going into and out of them.   But they can have some glitchy behavior.

One that’s now bitten me in the ass twice (6 years apart) is the fact that the HDA’s Python Module has no idea where the hell it is.  It doesn’t know where it’s instantiated and it doesn’t know anything about what’s attached to it, or … Read the rest

Threads and Cores.

Eventually, I’ll need to upgrade my dev workstation from the 4-core Intel Core i5 I have now to something a little speedier and beefier. Unreal Engine 4 likes to recompile its shader library often enough that it slows me down, and building for multiple platforms can take its toll as well.

I think I’m going to go AMD this round, probably a 12 or 16 core Threadripper, and in my poking around, I found this article by Sebastian Aaltonen, founder of Second Order Games and formerly a lead rendering engineer at Ubisoft.

Lots of solid advice and test results in … Read the rest

Windowpane – Through the Device

The biggest irritation I’ve found with the Magic Leap so far (there are others, but they’re not as big) is the state of video capture.

  • The capture camera and the render camera are offset from each other, so nothing lines up in a recorded video
  • The FOV is not good.  If you want something captured, it needs to be pretty much dead center of your view.
  • Getting media off the device is OK, on par with pulling movies from iPhone onto a PC, and the Device Bridge app in the Lab makes it easy.

I won’t pretend to understand the … Read the rest

Milestone: MagicWax MVP

So a thing happened over the weekend. My scheme to mash up spatial computing and DJing became real. Here’s a clip:

So what’s happening here is this: The earlier Raspberry Pi with AudioInjector HAT now has a twin, with a cloned SD card of the first one.

There is a Pyle 444 preamp on each one:

This is necessary to unwrap the RIAA curve from the turntable signal and turn it into line level, which is what the Audioinjector HAT needs. In order to cure the abysmal latency brought on by the import process over X11, a single-deck instance of … Read the rest