For years now, people have been trying to stuff an Intel processor on a credit card sized board. An x86 board that can fit in your pocket is an intriguing device – after all, that’s what Gumstix, the forerunner of the Raspberry Pi, were. Efforts to put x86 on a dev board have included the Minnowboard, the Intel Galileo and Edison, and even the Intel Compute Stick. These have not seen the uptake you would expect from a small x86-powered board, but that tide may soon turn. The UP board is exactly what you would expect from a Raspberry Pi-inspired board with a real Intel processor.
The feature set for the UP board is impressive for a credit card sized board; it’s powered by a quad-core Intel Atom x5-Z8300 CPU running at 1.84 GHz. The board comes equipped with 1GB of RAM, 16GB of eMMC Flash, Gigabit Ethernet, five USB 2.0 ports (one on a pin header) and one USB 3.0 port. Up also includes a real-time clock, HDMI, the same 40-pin GPIO pin connector found in the Raspberry Pi Model B Plus, and DSI and CSI connectors for the Raspberry Pi camera and touch screen.
To be fair to all the previous attempts at making a board built around an x86 chip that borrows heavily from the Raspberry Pi, there haven’t been many chips out there that have been suitable for credit card-sized applications. Only in the last year or so has Intel released chips suitable for an x86 single board computer, and the growing market of Windows 10 tablets bears this out. While it remains to be seen if the UP board will be a success, more than a few people will pick one of these up for a miniature Skype box.
FPGA development has advanced dramatically in the last year, and this is entirely due to an open-source toolchain for Lattice’s iCE40 FPGA. Last spring, the bitstream for this FPGA was reverse engineered and a toolchain made available for anything that can run Linux, including a Raspberry Pi. [Dave] from Xess thought it was high time for a Raspberry Pi FPGA board. With the help of this open-source toolchain, he can program this FPGA board right on the Raspberry Pi.
The inspiration for [Dave]’s board came from the XuLA and StickIt! boards that give the Raspberry Pi an FPGA hat. These boards had a problem; the Xilinx bitstreams had to be compiled on a ‘real’ PC and brought over to the Raspberry Pi world. The new project – the CAT Board – brings an entire FPGA dev kit over to the Raspberry Pi.
The hardware for the CAT Board is a Lattice iCE-HX8K, 32 MBytes of SDRAM, a serial configuration flash, LEDs, buttons, DIP switches, grove connectors, and SATA connectors (although [Dave] is just using these for differential signals; he doesn’t know if he can get SATA hard drives to work with this board).
Despite some problems with his board house, [Dave] eventually got his FPGA working, or at least the bitstream configuration part, and he can blink a pair of LEDs with a Raspberry Pi and programmable logic. The Hello World for this project is done, and now the only limit is how many gates are on this FPGA.
Continue reading “FPGAs For The Raspberry Pi”
An icon of Computer Science, [Edsger Dijkstra], published a letter in the Communications of the Association of Computer Machinery (ACM) which the editor gave the title “Go To Statement Considered Harmful“. A rousing debate ensued. A similar criticism of macros, i.e. #define, in C/C++ may not rise to that level but they have their own problems.
Macros are part of the preprocessor for the C/C++ languages which manipulates the source code before the actual translation to machine code. But there are risks when macros generate source code. [Bjarne Stroustrup] in creating C++ worked to reduce the need and usage of the preprocessor, especially the use of macros. In his book, The C++ Programming Language he writes,
Don’t use them if you don’t have to. Almost every macro demonstrates a flaw in the programming language, in the program, or in the programmer.
As C retrofitted capabilities of C++, it also reduced the need for macros, thus improving that language.
With the Arduino using the GNU GCC compilers for C and C++ I want to show new coders a couple of places where the preprocessor can cause trouble for the unwary. I’ll demonstrate how to use language features to achieve the same results more cleanly and safely. Of course, all of this applies equally when you use any of these languages on other systems.
We’re only going to be looking at macros in this article but if you want to read more the details about them or the preprocessor see the GNU GCC Manual section on the preprocessor.
Continue reading “Code Craft: When #define is Considered Harmful”
[Kratz] just turned into a rock hound and has a bunch of rocks from Montana that need tumbling. This requires a rock tumbler, and why build a rock tumbler when you can just rip apart an old inkjet printer? It’s one of those builds that document themselves, with the only other necessary parts being a Pizza Hut thermos from the 80s and a bunch of grit.
Boot a Raspberry Pi from a USB stick. You can’t actually do that. On every Raspberry Pi, there needs to be a boot partition on the SD card. However, there’s no limitation on where the OS resides, and [Jonathan] has all the steps to replicate this build spelled out.
Some guys in Norway built a 3D printer controller based on the BeagleBone. The Replicape is now in its second hardware revision, and they’re doing some interesting things this time around. The stepper drivers are the ‘quiet’ Trinamic chips, and there’s support for inductive sensors, more fans, and servo control.
Looking for one of those ‘router chipsets on a single board’? Here you go. It’s the NixCoreX1, and it’s pretty much a small WiFi router on a single board.
[Mowry] designed a synthesizer. This synth has four-voice polyphony, 12 waveforms, ADSR envelopes, a rudimentary sequencer, and fits inside an Altoids tin. The software is based on The Synth, but [Mowry] did come up with a pretty cool project here.
Over on Hackaday.io, [Dave Vandenbout] has posted the CAT board, a Raspberry Pi
daughterboard hat that features a Lattice FPGA, 32 MB of RAM, EEPROM, and a few Grove and PMOD connectors. The CAT takes advantage of the open source tool chain available for Lattice including the Python-based MyHDL (although, you could just use Verilog directly, if you prefer) and Icestorm. One interesting point: you can run the tool chain on the Raspberry Pi, resulting in a self-contained and largely portable FPGA development environment.
Continue reading “Open Source FPGA Pi Hat”
Not everyone likes Scratch — the block-oriented programming language that MIT developed to help kids program. While dyed-in-the-wool programmers probably find it limiting, it can be an effective way to teach basic programming to newcomers and there are some people who enjoy the graphical style of programming.
The latest Raspbian release (the operating system image for Raspberry Pi) has a new and improved version of Scratch for those who want to use it on the Pi. According to the Raspberry Pi blog, the new version is up to ten times faster than previous versions and also includes an improved method for Scratch programs to access the board’s general purpose I/O and other I/O devices.
Continue reading “Latest Raspberry Pi Images have Improved Scratch”
War, huh, what is it good for? Absolutely nothing, except as an excuse to build a Raspberry Pi powered sentry turret that will track and fire upon your enemies. That’s what [Matt Desmaris] decided to do, and he has released the full details of his build.
It lacks the polished elegance of most military hardware, but what do you expect of a quick and dirty hack? It’s not shiny or ominous, but it has that killer motion-tracking feature. [Matt] is using OpenCV to detect movement from a USB webcam, two servos to pan and tilt the camera and gun and a small relay to pull the trigger. Manual control over the Interwebs is also available.
We’ve seen lots of similar builds using weaponry such as rubber bands and Nerf guns, but this one is a great start if you are interested in seeing how you can tie together tools like OpenCV and servos to create a camera that actively tracks movement.