标签: GPAK4

Much like Douglas Adams' fictional detective Dirk Gently, I'm a great believer in "the fundamental interconnectedness of all things" and how one thing so often leads to another.   Several days ago, for example, I received a bunch of emails requesting consideration for a free GPAK4 development board. The problem was that I'd written about it yonks ago.   So I asked one of the guys what had led him to that article, and he responded that he'd seen a reference to it on the DangerousPrototypes.com website. Well, this sounded like an intriguing destination, so I immediately bounced over there to take a look, and the first thing I saw was something called the DigiRule.     This little beauty was created by a guy called Brad. You can find out more about Brad and his creations at BradsProjects.com . In a nutshell, the DigiRule is a 6-inch (15 cm) ruler whose divisions are marked in binary rather than decimal.   On the rear of the ruler we find useful information like logic gate and flip flop truth tables, a binary conversion chart, a few select SMD component footprints, and some hole sizes. On the front -- as you can see in this video -- we find a bunch of buttons and LEDs and digital functions like primitive logic gates, different types of register elements, and a 4-bit binary up/down counter (all of these functions are actually implemented using one of Microchip Technology's PIC18F43K20 microcontrollers).   As I've said before on many occasions: "Show me a flashing LED and I'll show you a man drooling!" I want one. Brad isn’t selling them. I'm going to have to build my own. Even better, maybe I can persuade my chum Duane Benson to build some for us, because (a) he can whip out a new board design much faster than yours truly and (b) his designs usually work first time.   But if we're going to build our own, then you can bet we're going to add a few features of our own. For example, we could make the little rascal Arduino/chipKIT compatible and provide it with a USB port so folks can hack it if they wish (we'd make this an open source design, of course).   I do like the simple logic functions and registers on Brad's ruler, but -- in the case of the simple logic gates, for example -- he uses only one color of LED. Thus, in the case of the AND, function, the LED representing the output is only on (logic 1) if both of the inputs are on (logic 1). I'd prefer to use bi-colored LEDs, where green represents logic 0 and red represents logic 1, for example.   What else could we add? How about a real-time clock capability, possibly with a small OLED display to present the time? (I think we're going to need to use a rechargeable battery.) Maybe connection points for two flying lead probes and a piezoelectric sounder so we could use it as a continuity tester -- perhaps even a simple multimeter...   What say you? If you were going to do this, what would you include on the little scamp? Any suggestions will be gratefully received, but you'd better throw them into the mix quickly.

Twenty-five of Silego's GPAK4 mixed-signal FPGA development kits are currently winging their way to the folks who teased and tempted me the most with their imaginative project proposals.   One of these guys was Harjit Singh, who hails from the state of Washington. In his email to me, Harjit managed to press two of my hot buttons at the same time -- space and robots.   More specifically, in Harjit's message he said: "I'd like to be considered for a GPAK4 development kit because I want to see if I can use it to create a robust watchdog system for use in space. Also, I build robots and I would like to see if I can use a GPAK4 for sensor conditioning."   Now, when someone says "robot," I have to admit that my knee-jerk reaction is of a full-size humanoid creation like Ada in my Alex + Ada column. In this case, however, Harjit was actually referring to a micro-mouse incarnation as illustrated in this video (also, you can click here to see a bunch of videos staring Harjit as himself along with his performing mice).   Did you see how fast the mouse was? If that scampered across the floor in front of me when I wasn't expecting it, I think you'd hear me squealing like a schoolgirl while leaping onto the nearest table. These micro-mice are really rather impressive, especially when you compare them to this demonstration by Claude Shannon in the 1950s. My initial reaction when I first saw this was: "Good grief, how on earth could they make robot mice this small in the 1950s?"   It only took me a few seconds to realize what they must have done -- or at least, to decide the way in which I would have achieved this using the technology of the time -- and I was right. As you'll see if you watch the video, the "brain" of the mouse is a honking big relay computer that's hidden out of sight, while its "muscles" (motive force) are actually located in the table.   Returning to today's micro-mice, Harjit informs me that mouse competitions take place across the US, and that the next big one will occur in March at APEC 2016 .   All of this has set my mind buzzing. First, I wonder what Claude Shannon's reaction would have been if I were to hop into my trusty time machine and take one of Harjit's micro-mice back to the 1950s. Second, I want to build my own micro-mouse. I'm hoping to persuade Harjit and his fellow Mouseketeers (I'm sorry, I couldn’t help myself) to write a column telling us more about the physical specifications for the mice and the goals of the competition. Until then, if you'll excuse me, I'm going to watch some more mouse videos (and it's not often you'll hear me say that).

The vast majority of the embedded designers I know generally create MCU-based systems -- they rarely even consider using a Field-Programmable Gate Array (FPGA).   Now, I think just about every embedded designer has at least heard of FPGAs. They understand that these devices can be configured to perform different tasks, and they may also know that FPGA designers typically use languages like Verilog and VHDL to capture their designs, but that's about it -- they don’t actually know how these devices perform their magic, and they don’t really understand how the design in Verilog or VHDL is "compiled" into the FPGA.   One important thing to note here is that not all FPGAs are created equal. At one end of the spectrum we have humongous devices from Xilinx and Altera that can contain multiple processor cores and the equivalent of multiple millions of ASIC gates. Then we have some very tasty and affordable mid-range devices from companies like Lattice Semiconductor. And we also have some very interesting PSoC (Programmable SoC) devices from Cypress Semiconductor that contain a 32-bit processor core along with programmable analog fabric and programmable digital fabric.   All of these devices are capable of extraordinary things, yet embedded designers still tend to steer clear of them. Perhaps what is required is some way of "dipping one's toes into the water," as it were -- some way to experiment with programmable device technology without making one's brains leak out of one's ears. If so, Silego's teeny-tiny mixed-signal GPAK devices might be just what you are looking for.   I think of these GPAK chips as super-small mixed-signal FPGAs that you can literally design and program in just a few minutes, and that cost only a few cents each. GPAK mixed-signal FPGAs allow you to replace a number of off-the-shelf "glue" chips and gather their functionality into a single low-cost device. In addition to minimizing the component count and reducing costs, this shrinks board size and reduces power consumption.   The most recent addition to the GPAK family is the GPAK4 , and the first member of this fourth generation is the SLG46620V. Presented in a 20-pin STQFN package (2.0 x 3.0 x 0.55mm with an 0.4mm pitch) and supporting a supply voltage of 1.8V to 5.0V, this little rascal boasts 18 general-purpose input/outputs (GPIOs), 6 analog comparators ACMPs, 3 digital comparators/pulse-width modulators DCMPs/PWMs, 2 digital-to-analog converters (DACs), 25 lookup tables (LUTs), and a variety of counter, delay, and flip-flop macrocells.     These tiny devices can be used to implement a wide variety of system functions, including comparators, logic, delays, counters, resets, power sequencing, voltage sensing, and interface circuits -- all while minimizing component count, board space, and power consumption.   One of the things the folks at Silego have done really well is to create an intuitive, easy-to-use, drag-and-drop graphical user interface (GUI) interface called GreenPAK Designer that allows you to play "what-if" games with different configuration scenarios, including defining input stimulus and simulating the way in which the GPAK will behave.     The image above shows relatively simple stimulus waveforms, but you can use the custom wizard to literally draw any waveforms you wish, thereby allowing you to verify how your design will respond to "interesting" input signals (e.g., signals with noise spikes). The GreenPAK Designer software is available free for Windows, Mac, and Linux platforms -- in fact I just downloaded the latest version to play with myself.   Once you've evaluated your design in the virtual world, you might decide to invest in a GreenPAK4 Development Kit as shown below.   This kit -- which costs only $59 -- includes a Universal Development Board, a GreenPAK4 TQFN-20 Socket Adapter, some SLG46620V samples, a USB Cable (A to Mini B), and a Quick Start Guide. Using this kit, you can verify your stimulus against a real device and monitor its real-world responses. When you're ready to rock-and-roll, you can program your design into the GPK4's non-volatile memory, pop it out of the socket adapter, and solder it onto your board. (When you are ready to go into production, Silego can make your life easy by delivering pre-programmed GPK4s to you.)   Now, Silego's target markets typically involve large-volume production runs. Having said this, for only $59 for the development kit with SLG46620V sample devices, I personally can see myself using these little beauties in my hobby projects and prototypes. If you have a few moments spare, why not download a free copy of the GreenPAK Designer software, have a play, see what you think, and then post a comment here sharing your findings with the rest of us. You never know; if you like working with GPAK4 devices, you might start thinking about experimenting with larger FPGAs in the future.