FPGAs are a fascinating piece of technology. Gaming can also fascinate. Merging the two in a retro recreation of a the classical NES means that I have to write about it.
Ludde (from Gothenburg, just as myself) built a NES inside a Xilinx Spartan-6 FPGA as a project over Christmas. The system drives a VGA output and emulates the CPU, PPU and APU, i.e. processing, graphics and audio units. Conveniently enough, the controllers are hooked up via USB, so you do not have to dig out the originals.
Over the last year, or there about, we’ve had Flattr links at the bottom of all posts on Digital Fanatics. The total yield of these is EUR0.52, or which one payment came from Thingiverse and the other from my account on Flattr.
The conclusion of this is that this site either targets the wrong audience, or that Flattr does not work. I kind of liked their idea, but for now, the link goes away.
Jörg Wolfram has re-created the ZX81 system using an ATMega AVR MCU. The system uses a PS2 keyboard, NTCS (or VGA/LCD) for graphics and an SD-card instead of a tape. Looks like a great recreation of the past. The curious can read more about it here (Google translated, original German here)
We have a large scanner / copier / printer at the office. Large and rather expensive, it carries out some basic tasks. One of my favorite features of this oversized beast is that it can scan documents and sending them to me over email. Great for expense reports!
Now you can do this using your Raspberry Pi and an old scanner instead. Eduardo Luís has come up with a solution with a single button for scan-and-email and a pair of LEDs for the status. Seems like a very convenient solution to me. All that is missing to replace the big scanner here would be a printer and a way to select where the scan would go (to who or to the printer). Still, it is 35$ and an old scanner – and it takes up less space than the office style scanner / copier / printer.
Ken Shirriff has been working hard lately. In two great reads, he presented details from the classic CPUs 6502 and 8085. Basically, what he does is that he picks apart the overflow flag of the 6502 and the ALU of the 8085 in very, very, very great detail. For the 6502, he actually shows the wires and junctions on the silicon.
All the information comes from the Visual 6502 project, but the interpretation and explanation is all Ken’s. Great read, and nice to see that a full CPU really only consists of the basic components everyone can grasp.
As fun as bitbanging might be, hardware implementation of wire-level protocols can be really handy. Hackaday writes about Louis Thiery‘s and Brian Hensley‘s work towards enabling SPI on the Raspberry Pi.
They both show how to get SPI working on the RPi, and then Louis continues to show how to interact with it from Python. This opens up a whole world of cheap peripherals that can be connected to the RPi. Before you go shopping though, a word of caution. The RPi is not very fond of 5V on the GPIO pins. It is recommended that you get a level shifter before you play.
One of the problems when 3D printing is the cost of filament. Especially since you tend to improve designs incrementally and end up with lots of intermediate step test prints that you need to scrap.
The Filabot team wants to change this. They want to enable you to take your scrap plastic and turn it into filament again. They also want to let you take your plastic items in your home and turn them into filament. Basically, they want to let you make your own filament from whatever you have laying around.
Earlier we wrote of an OS for FPGAs. Today, we turn our attention for a real-time operating system for TI microcontrollers: TI-RTOS. The good part: it is a complete RTOS with support for USB, TCP/IP and FAT filesystems. The less good part: the license limits the OS to be used for TI devices.