Software Development

784 Articles

Remoticon Video: How To Use Max In Your Interactive Projects

December 17, 2020 by 14 Comments

When you want to quickly pull together a combination of media and user interaction, looking to some building blocks for the heavy lifting can be a lifesaver. That’s the idea behind Max, a graphical programming language that’s gained a loyal following among anyone building art installations, technology demos (think children’s museum), and user Kiosks.

Guy Dupont gets us up to speed with a how to get started with Max workshop that was held during the 2020 Hackaday Remoticon. His crash course goes through the basics of the program, and provides a set of sixteen demos that you can play with to get your feet under you. As he puts it, if you need sound, video, images, buttons, knobs, sensors, and Internet data for both input and output, then Max is worth a look. Video of the workshop can be found below.

Continue reading “Remoticon Video: How To Use Max In Your Interactive Projects” →

Learn Compilers Online From Cornell

December 16, 2020 by 29 Comments

It sounds like the start of a joke, but what’s the difference between taking Cornell’s CS6120 online and in-person? The instructor, [Adrian Samspon] notes that the real class has deadlines, an end-of-semester project, and a discussion board that is only open to real-life students. He also notes that you only earn “imagination credits.”

Still, this is a great opportunity to essentially audit a PhD-level computer science class on a fascinating topic. The course consists of videos, papers, and open source projects using LLVM and a custom internal representation based on JSON that is made for the class. It is all open source, too. You do however need access to the papers, some of which are behind paywalls. Your local library can help if you can’t otherwise find copies of the papers.

Continue reading “Learn Compilers Online From Cornell” →

Bare-Metal STM32: Blinky And The Secret Of Delay Functions

December 11, 2020 by 35 Comments

One of the very first examples for an MCU or SoC usually involves the famous ‘Blinky‘ example, where an LED is pulsed on and off with a fixed delay. This is actually a lot more complicated than the ‘Pushy‘ example which we looked at in the first installment of this series. The reason for this is that there’s actually quite a story behind a simple call to delay() or its equivalent.

The reason for this is that there are many ways to implement a delay function on a microcontroller (MCU), each of which comes with their own advantages and disadvantages. On an STM32 MCU, we get to choose between essentially an active delay (while loop), one implemented using the SysTick timer and using one of the peripheral timers. In the latter two cases we also have to use interrupts.

In this article we’ll take a look at all three approaches, along with their advantages and disadvantages.

Continue reading “Bare-Metal STM32: Blinky And The Secret Of Delay Functions” →

Inside CHIP-8

December 7, 2020 by 4 Comments

Certain old computers — most frequently those using the RCA 1802 — were fond of using an early form of byte-code interpreter for programs, especially games. The interpreter, CHIP-8, was very simple to create but offered high-level features that were tedious to recreate in the native assembly language. Because there are a fair number of simple games written in CHIP-8, there are of course, emulators for it, and [River Gillis] decided to look inside the CHIP-8 byte code interpreter.

Part of the power of CHIP-8 was it only had 35 virtual instructions. That was important when you were trying to shoehorn a game and the interpreter into a very small memory. Remember, in those days 1K of memory wasn’t an unusual number, although the prototypical CHIP-8 host would have 4K.

Continue reading “Inside CHIP-8” →

Procedurally Generated Trees

November 20, 2020 by 16 Comments

As the leaves fall from the trees here in the Northern Hemisphere, we are greeted with a clear view of the branches and limbs that make up the skeleton of the tree. [Nicolas McDonald] made a simple observation while looking at trees, that the sum of the cross-sectional area is conserved when a branch splits. This observation was also made by Leonardo Da Vinci (according to Pamela Taylor’s Da Vinci’s Notebooks). Inspired by the observation, [Nicolas] decided to model a tree growing for his own curiosity.

The simulation tries to approximate how trees spread nutrients. The nutrients travel from the roots to the limbs, splitting proportionally to the area. [Nicolas’] model only allows for binary splits but some plants split three ways rather than just two ways. The decision on where to split is somewhat arbitrary as [Nicolas] hasn’t found any sort of rule or method that nature uses. It ended up just being a hardcoded value that’s multiplied by an exponential decay based on the depth of the branch. The direction of the split is determined by the density of the leaves, the size of the branch, and the direction of the parent branch. To top it off, a particle cloud was attached at the end of each branch past a certain depth.

By tweaking different parameters, the model can generate different species like evergreens and bonsai-like trees. The code is hosted on GitHub and we’re impressed by how small the actual tree model code is (about 250 lines of C++). The power of making an observation and incorporating it into a project is clear here and the results are just beautiful. If you’re looking for a bit more procedurally generation in your life, check out this medieval city generator.

Bare-Metal STM32: From Power-Up To Hello World

November 17, 2020 by 59 Comments

Some may ask why you’d want to program a Cortex-M microcontroller like the STM32 series using nothing but the ARM toolchain and the ST Microelectronics-provided datasheet and reference manual. If your first response to that question wasn’t a panicked dive towards the nearest emergency exit, then it might be that that question has piqued your interest. Why, indeed?

Definitely, one could use any of the existing frameworks to program an STM32 MCU, whether the ST HAL framework, plain CMSIS, or even something more Arduino-flavored. Yet where is the fun in that, when at the end of the day one is still fully dependent on that framework’s documentation and its developers? More succinctly, if the contents of the STM32 reference manuals still look like so much gibberish, does one really understand the platform?

Let’s take a look at how bare-metal STM32 programming works, and make the most basic example run, shall we? Continue reading “Bare-Metal STM32: From Power-Up To Hello World” →

FreeCAD Debugging

November 16, 2020 by 20 Comments

Powerful software programs often have macro programming languages that you can use, and if you know how to program, you probably appreciate them. However, sometimes the program’s built-in debugging facilities are lacking or even nonexistent If it were just the language, that wouldn’t be such a problem, but you can’t just grab a, for example, VBA macro from Microsoft Word and run it in a normal Basic interpreter. Your program will depend on all sorts of facilities provided by Word and its supporting libraries. [CrazyRobMiles] was frustrated with trying to debug Python running inside FreeCAD, so he decided to do something about it.

[Rob’s] simple library, FakeFreeCad, gives enough support that you can run a FreeCAD script in your normal Python development environment. It only provides a rude view of what you are drawing, but it lets you explore the flow of the macro, examine variables, and more.

Continue reading “FreeCAD Debugging” →