Building a USB bootloader for an STM32


Kevin Cuzner writes:

As my final installment for the posts about my LED Wristwatch project I wanted to write about the self-programming bootloader I made for an STM32L052 and describe how it works. So far it has shown itself to be fairly robust and I haven’t had to get out my STLink to reprogram the watch for quite some time.
The main object of this bootloader is to facilitate reprogramming of the device without requiring a external programmer.

More details on Projects & Libraries’ homepage.

Raspberry Pi GPIO programming in C


Steve Chamberlin has written an article about Raspberry Pi GPIO programming in C:

The Raspberry Pi’s 40-pin GPIO connector often gets overlooked. Typical Pi projects use the hardware as a very small desktop PC (RetroPie, Pi-hole, media center, print server, etc), and don’t make any use of general-purpose IO pins. That’s too bad, because with a little bit of work, the Raspberry Pi can make a powerful physical computing device for many applications.

More details at Big Mess o’ Wires homepage.

Programmable LED dimmer


Programmable LED dimmer from Soldernerd:

Around one and a half years ago I’ve designed and built various LED dimmers for both white and RGB LEDs. Then late last year someone approached me asking if I could make an RGB dimmer for him, too. But my designs were really tailored to their specific applications and built with home-made, i.e. milled PCBs which are time-consuming to make. So I decided to make a more universal version based on a proper, etched board which could be built in a small series and used for all kind of applications, both white and RGB. The result is this versatile, programmable 4-channel dimmer.
The design is based on my previous RGB dimmer but with a number of improvements.

Project info at Soldernerd homepage and the GitHub repository here.

“Hello world” in the BCPL language on the Xerox Alto simulator


Ken Shirriff writes:

The first programming language for the Xerox Alto was BCPL, the language that led to C. This article shows how to write a BCPL “Hello World” program using Bravo, the first WYSIWYG text editor, and run it on the Alto simulator.
The Xerox Alto is the legendary minicomputer from 1973 that helped set the direction for personal computing. Since I’m helping restore a Xerox Alto (details), I wanted to learn more about BCPL programming. (The influential Mesa and and Smalltalk languages were developed on the Alto, but those are a topic for another post.)

Full details at Ken Shirriff’s blog.