Minimal ATSAMD21 computer


Johnson Davies shared detailed instructions of how to build an ATSAMD21-based computer on a prototyping board using a 32-pin ATSAMD21E:

If you’re looking for something more powerful than the ATmega328 in the Arduino Uno a good choice is the ATSAMD21. This is an ARM Cortex M0+ processor with up to 256KB flash memory, 32KB RAM, and a 48MHz clock, so it’s substantially better equipped than the ATmega328. In addition it has a USB interface built in, so there’s no need for a separate chip to interface to the serial port.
Arduino have designed several excellent boards based on the ATSAMD21, such as the Arduino Zero or smaller-format MKRZERO. However, these boards are an expensive way to use an ATSAMD21 as the basis for your own project, and they probably include many features you don’t need.

More details on Technoblogy.

Scott’s Z80SBC: Z80 single board computer


Dr. Scott M. Baker published a new build:

When I was first getting started with electronics, wanted a Heathkit ET-3400 Microproccessor trainer, but could never afford one at the time. Eventually both I and the world moved on, to fancier more capable computers. However, I’ve still always wished I had an iconic trainer, complete with LED displays and a hexadecimal keypad. So I decided to build something of my own.

Project info at and the GitHub repository here.

Check out the video after the break.

Repairing a 1960s mainframe: Fixing the IBM 1401’s core memory and power supply


Ken Shirriff wrote a great article describing the repair process of  the vintage IBM 1401 mainframe computer:

The problem started when the machine was powered up at the same time someone shut down the main power, apparently causing some sort of destructive power transient. The computer’s core memory completely stopped working, making the computer unusable. To fix this we had to delve into the depths of the computer’s core memory circuitry and the power supplies.

See the full post on his blog.

Pick-And-Place Machine for Candy

Every December and May the senior design projects from engineering schools start to roll in. Since the students aren’t yet encumbered with real-world detractors (like management) the projects are often exceptional, unique, and solve problems we never even thought we had. Such is the case with [Mark] and [Peter]’s senior design project: a pick and place machine that promises to solve all of life’s problems.

Of course we’ve seen pick-and-place machines before, but this one is different. Rather than identifying resistors and capacitors to set on a PCB, this machine is able to identify and sort candies. The robot — a version of the MeARM — has three degrees of freedom and a computer vision system to alert the arm as to what it’s picking up and where it should place it. A Raspberry Pi handles the computer vision and feeds data to a PIC32 which interfaces with the hardware.

One of the requirements for the senior design class was to keep the budget under $100, which they were able to accomplish using pre-built solutions wherever possible. Robot arms with dependable precision can’t even come close to that price restraint. But this project overcomes the lack of precision in the MeArm by using incremental correcting steps to reach proper alignment. This is covered in the video demo below.

Senior design classes are a great way to teach students how to integrate all of their knowledge into a final class, and the professors often include limits they might find in the real world (like the budget limit in this project). The requirement to thoroughly document the build process is also a lesson that more people could stand to learn. Senior design classes have attempted to solve a lot of life’s other problems, too; from autonomous vehicles to bartenders, there’s been a solution for almost every problem.

Filed under: robots hacks

Zeta 2 single board computer


Scott Baker has a nice write-up on building a Zeta v2 single board computer designed by Sergey Kiselev:

A few of the features of the Zeta 2:

  • 512K Flash Memory, allows CP/M to be booted from Flash, and mounts Flash as a CP/M disk including many tools (assembler, editor, …)
  • 512K Flash ROM, can be used as RAM Disk. Supports battery backup.
  • 16550 UART provides a single serial port
  • 8255 PIO supports up to three 8-bit serial ports
  • Dallas 1210 Real-Time Clock
  • WD37C65 floppy controller, easily supports 3.5″ PC Floppy Drives

Project info at Scott Baker’s blog.

Check out the video after the break.

Script Your Way Out Of Video Editing Drudgery

[Victor Frost] has a deep voice and a fancy top of the line camera. While one would assume this to be a more than generous situation for life to put a person in; it’s got its own set of problems. Mainly that his fantastic fancy camera uses the most modern version of the popular h.264 encoding scheme, h.265. Gasp!

While that too seems like a pro, unfortunately h.265 doesn’t play as nice with his editing software. The solution seems easy, just transcode it and get on your way. However, when you start talking about transcoding 4K video from a top-of-the line source and retaining the quality. Well… It can bring a processor to its knees. Since he’d rather be playing overwatch than transcoding video on his main computer, he decided to offload and automate the drudgery to his spare.

That’s how the Ingest-a-Tron 9000 came into play. It uses a lot of open source software and, yes, windows batch files to take the files off his camera, process it on one computer, and dump it to another. Now he can game (or edit) while he waits. For those of us who are estranged from Linux thanks to our favorite software, it’s good to know that there are still ways to automate away the pain. Video after the break.

Filed under: computer hacks, video hacks

Hook Any Mouse to an Acorn

Acorn was one of the great IT giants that rose high and then fell to obscurity during the rise of personal computing. However, for many hobbyists these computers are as important and as loved as the Commodore 64. [Simon Inns] has made a great adapter to interface modern USB mice to these old boxes. 

After thirty years of interaction with people, one might be hard pressed to find a working mouse for an older computer. On top of that, even if you did, these mice are likely a lackluster experience to begin with. They were made long before industrial designers were invited to play with computers and are often frustrating and weird. Cotton swabs and alcohol are involved, to say the least.

[Simon]’s box converts a regular USB HID compliant mouse to a quadrature signal that these 8-bit computers like. The computer then counts the fake pulses and happily moves the cursor around. No stranger to useful conversion boxes, he used an Atmel micro (AT90USB1287) with a good set of USB peripherals. It’s all nicely packed into a project box. There’s a switch on the front to select between emulation modes.

If you’d like one for yourself the code and schematics are available on his site. As you can see in the video below, the device works well!

Filed under: computer hacks