Printer Scrap Becomes FPGA Devboard

These days, if you want to start learning about FPGAs, it can be a daunting experience. There’s a huge variety of different platforms and devboards and it can be difficult to know where to start. [RoGeorge] decided to take a different tack. Like a 16-year-old drag racer, he decided to run what he brung – a printer control panel cum FPGA development board (Romanian, get your Google Translate on).

[RoGeorge] was lucky enough to score a couple of seemingly defective control panels from HP Laserjets discarded by his workplace. Seeing potentially good parts going to waste, like keypads and LCDs, he decided to investigate them further – finding a 50,000 gate Xilinx Spartan IIE running the show. Never one to say no to opportunity, [RoGeorge] dived in to learning how to work with FPGAs.

The forum posts are a great crash course in working with this sort of embedded FPGA platform. [RoGeorge] covers initial mapping of the peripherals on the board & finding a JTAG connector and programming solution, before moving on to basic FPGA programming and even covers the differences between sequential programming on microcontrollers and the parallel operation of FPGAs. Even if you don’t intend to get down and dirty with the technology, spend half an hour reading these posts and you’ll be far more knowledgeable about how they work!

In the end, [RoGeorge] showed how to teach yourself to work with FPGAs for the price of a couple of programming cables – not a mean feat by any means. It’s a testament to the hacker spirit, and reminds us of [SpriteTM]’s efforts in hacking hard drive controllers.

Zork Comes to Custom FPGA CPU (Again)

[Robert Baruch] wanted to tackle a CPU project using an FPGA. One problem you always have is you can either mimic something that has tools and applications or  you can go your own way and just build everything from scratch (which is much harder).

[Robert] took the mimic approach–sort of. He built a CPU with the express idea of running Infocom’s Z-machine virtual machine, which allows it to play Zork. So at least when you are done, you don’t have to explain to your non-tech friends that it only blinks an LED. Check out the video, below, for more details.

Continue reading “Zork Comes to Custom FPGA CPU (Again)”

Adding IceZero To The Raspberry Pi

[Kevinhub] noticed there were quite a few FPGA hats for the Raspberry Pi. Instead going out and buying one of these boards like a filthy commoner, he decided to spin up his own FPGA Pi accessory. This IceZero FPGA board combines the best features from other FPiGA boards, and does it in a form factor that fits right on top of the minuscule Pi Zero.

If you think slapping a Lattice FPGA onto a Pi has been done before, you’re right. Here’s a hat for the Pi using an iCE5LP4K-SG48, an FPGA with 3520 LUTs. The CAT Board from Xess has a slightly bigger FPGA with 7680 logic cells, and the FleaOhm has a monster FPGA on board that costs about $70 USD.

[Kevin]’s IceZero is at the lower end of these Raspberry Pi FPGA hats, using a Lattice ICE40HX4K. That’s only 3520 logic cells, but it only costs about $7 USD in quantity one. The board design is a standard two layer board that shouldn’t be too terrible for hand soldering. The boards are shared on OSH Park, should you want to test this little guy out.

This Pi Hat is specifically designed to be used with Project IceStorm, the Open toolchain for Lattice’s iCE40 FPGAs. That means there’s already a few projects out in the wild that can be easily ported to this platform, and already [Kevin] has a logic SUMP example going on his board.

Ice, Ice, Radio Uses FPGA

Building a software defined radio (SDR) involves many trades offs. But one of the most fundamental is should you use an FPGA or a CPU to do the processing. Of course, if you are piping data to a PC, the answer is probably a CPU. But if you are doing the whole system, it is a vexing choice. The FPGA can handle lots of data all at one time but is somewhat more difficult to develop and modify. CPUs using software are flexible–especially for coding user interfaces, networking connections, and the like) but don’t always have enough horsepower to cope with signal processing tasks (and, yes, it depends on the CPU).

[Eric Brombaugh] sidestepped that trade off. He used a board with both an ARM processor and an ICE FPGA at the heart of his SDR design. He uses three custom boards: one is the CPU/FPGA board, another is a 10-bit converter that can sample at 40 MSPS (sufficient to decode to 20 MHz), and an I2S DAC to produce audio. Each board has its own page linked from the main project.

Continue reading “Ice, Ice, Radio Uses FPGA”

Persistence Of Vision Death Star

Death Stars were destroyed twice in the Star Wars movies and yet one still lives on in this 168 LED persistence of vision globe made by an MEng group at the University of Leeds in the UK. While Death Stars are in high demand, they mounted it on an axis tilted 23.4° (the same as the Earth) so that they can show the Earth overlaid with weather information, the ISS position, or a world clock.

More details are available on their system overview page but briefly: rotating inside and mounted on the axis is a Raspberry Pi sending either video or still images through its HDMI port to a custom made FPGA-based HDMI decoder board.  That board then controls 14 LED driver boards mounted on a well-balanced aluminum ring. All that requires 75W which is passed through a four-phase commutator. Rotation speed is 300 RPM with a frame rate of 10 FPS and as you can see in the videos below, it works quite well.

Continue reading “Persistence Of Vision Death Star”

FPGA Computer Covers A to Z

[F4HDK] calls his new computer A2Z because he built everything from scratch (literally, from A to Z). Well, strictly speaking, he did start with an FPGA, but you have to have some foundation. The core CPU is a 16-bit RISC processor with a 24-bit address bus and a 128-word cache. The computer sports 2 megabytes of RAM, a boot ROM, a VGA port and keyboard, and some other useful I/O. The CPU development uses Verilog.

Software-wise, the computer has a simple operating system, a filesystem, and basic programs like a text editor and an image viewer. Development software includes an assembler and a compiler for a BASIC-like language that resides on the PC. You can also run an emulator to experiment with A2Z without hardware. You can see a “car game” running on A2Z in the video below. You can also see videos of some other applications.

Continue reading “FPGA Computer Covers A to Z”

Retro ZX Spectrum Lives a Spartan Existence

FPGAs (like Xilinx’s Spartan series) are great building blocks. They often remind us of the 100-in-1 electronic kits we used to get as kids. Lots of components you can mix and match to make nearly anything. However, like a bare microcontroller, they usually don’t have much in the way of peripheral devices. So the secret sauce is what components you can surround the chip with.

If you are interested in retro computing, you ought to have a look at the ZX-Uno board. It hosts a Spartan 6 FPGA. They are for sale, but the design is open source and all the info is available if you prefer to roll your own or make modifications. You can see a video of the board in action, below (as explained in the video, the color issues are due to the capture card trying to deal with the non-standard sync rate).

Here are the key specifications:

  • FPGA Xilinx Spartan XC6SLX9-2TQG144C
  • Static Memory 512Kb, AS7C34096A-10TIN
  • 50MHz Oscillator
  • Video output (composite)
  • PS/2 keyboard
  • Stereo audio jack
  • EAR jack connector (for reading cassette tapes)
  • Connectors for JTAG and RGB
  • Slot for SD Cards
  • Expansion port with 3 male pin strips
  • Micro-USB power connector
  • PCB Size: 86×56 mm. (Compatible with Raspberry Pi cases)

Continue reading “Retro ZX Spectrum Lives a Spartan Existence”