Exploiting Hardware-Level Parallelism In The Manticore Hardware-Accelerated RTL Simulator

May 10, 2023 by Maya Posch 10 Comments

Before a chip design is turned from a hardware design language (HDL) like VHDL or Verilog into physical hardware, testing and validating the design is an essential step. Yet simulating a HDL design is rather slow due to the simulator using either only a single CPU thread, or limited multi-threading due to the requirements of fine-grained concurrency. This is due to the strict timing requirements of simulating hardware and the various clock domains that ultimately determine whether a design passes or fails. In a recent attempt to speed up RTL (transistor) level simulations like these, Mahyar Emami and colleagues propose a custom processor architecture – called Manticore – that can be used to run a HDL design after nothing more than compiling the HDL source and some processing. Continue reading “Exploiting Hardware-Level Parallelism In The Manticore Hardware-Accelerated RTL Simulator” →

Op-Amp Challenge: A Low Noise Amplifier For Those Truly Low Noise Measurements

May 6, 2023 by Jenny List 8 Comments

When something is described as “Low Noise”, it is by the nature of the language a relative phrase. The higest quality magnetic tape is low noise compared to its cheaper sibling for example, but still has noise many would consider unacceptable. In instrumentation however, “Low Noise” has to really mean just that, with a range of specialist techniques to produce circuitry with a truly low noise level for the most demanding of signal applications. As an example [Floydfish] has created a low noise instrumentation amplifier that should serve as a learning exercise for anyone interested in pushing low noise circuitry to the limit.

Anyone who can dredge the hazy recesses of their mind for barely-remembered electronics lectures will know that the overall noise figure of a system is dictated by that of its first component. Thus perhaps the most interesting part of the schematic is at the input, where a row of low-noise op-amps are presented in parallel. We have to admit having to look this one up, to find that it’s a technique whereby the signal outputs of each chip are the same and thus sum, while the noise output of each is different and thus the summed noise output is proportionally lower. This stage is then followed by a buffer and a set of filters for different output frequency ranges.

Our op-amp competition of which this is a part is certainly delivering the goods when it comes to the amny techniques with which these versatile parts can be used. Few of us may need to make such a low noise amplifier, but at least now we’ve learned how.

Op-Amp Challenge: Light Up Breadboard Shows Us The Signals

May 5, 2023 by Jenny List 5 Comments

Most Hackaday readers will no doubt at some point used a solderless breadboard for prototyping. They do the job, but sometimes their layout can be inflexible and keeping track of signals can be a pain. There’s a neat idea from [rasmusviil0] which might go some way to making the humble breadboard easier to use, it’s a breadboard in which each line is coupled via an op-amp buffer to an LED. In this way it can be seen at a glance some indication of the DC voltage present.

It’s an idea reminiscent of those simple logic probes which were popular years ago, but its implementation is not entirely easy. Each circuit is simple enough, but to replicate it across all the lines in a breadboard makes for a huge amount of quad op-amp chips stuffed onto one piece of stripboard as well as a veritable forest of wires beneath the board.

The effect is of a breadboard crossed with a set of blinkenlights, and we could see that for simple digital circuits it could have some utility if not so much for higher frequency or analogue signals. Certainly it’s an experiment worth doing, and indeed it’s not the first tricked out breadboard we’ve seen.

Op-Amp Challenge: Get More From A Single Wire With An Analogue Adder

May 4, 2023 by Jenny List 10 Comments

It’s been a running battle in some quarters for years, whether analog sensor processing is better than digital. Proponents of digital are sometimes driven by lack of familiarity with analog circuitry, while analog die-hards point to delays and software crashes in microcontrollers. We’d probably toe the line that a mixture of the two skills is best, but [paul] has gone full-on for the analog side with his position and limit sensor for a remote telescope. The ‘scope had only one control wire carrying a digital signal, so how was he to get extra information down it? The solution was to overlay a DC voltage, and use a summing network composed of a series of op-amps to encode position and limit data as voltage.

In operation, the circuit is a straightforward DC summing amplifier of the type that op-amps were designed for and at which they excel. We’re not so sure it needs the high-precision resistors and the choice of op-amps seems the wrong way round with the AD8532’s high current output being better suited to driving the line than straightforward summing, but we can see it does the job. If you’re after a demonstration of a DC summing amplifier using an op-amp, here’s your project. Meanwhile if you’re curious about an op-amp inside the black box, take a look at one of the simplest integrated circuit op-amps ever made.

Four square, unpopulated purple PCBs sit in front of a tube of soldering flux on a light grey work surface. The PCBs are only 1"x1".

BeagleStamp Makes Soldering Linux Into Your Projects Easier

May 4, 2023 by Navarre Bartz 44 Comments

There are a lot of things you can do with today’s powerful microcontrollers, but sometimes you really need a full embedded Linux setup. [Dylan Brophy] wanted to make it easier to add Linux to his own projects and designed the BeagleStamp.

Squeezed onto a 1″ square, the BeagleStamp puts the power of a PocketBeagle into an easy to solder module you can add to a project without all that tedious mucking about with individually soldering all the components of a tiny Linux computer every time. As a bonus, the 4 layer connections are constrained to the stamp as well, so you can use lower layer count boards in your project and have your Linux too.

The first run of boards was delivered with many of the pins unplated, but [Brophy] plans to work around it for the time being so he can spot any other bugs before the next board revision. Might we suggest a future version using RISC-V?

Op-Amp Challenge: Reliable Peak Power Measurement

May 3, 2023 by Jenny List 15 Comments

As part of our Op-Amp Challenge we’re seeing a wide diversity of entries showcasing the seemingly endless capabilities of these extremely versatile parts. Another one comes from [Joseph Thomas], who when faced with the need to measure the properties of an automotive spark plug, came up with a precision peak detector to hold on to the energy level used when firing it.

It starts with an op-amp buffer feeding a diode and capacitor. The capacitor is charged through the diode and holds the level, which can be read through another op-amp. Finally there’s an opto-isolated transistor to discharge the capacitor before a fresh reading is taken.

It’s a simple enough circuit but a very effective one. The op-amps used are bit old-school FET devices, but aside from the high impedance input their performance is hardly critical. Yet another op-amp circuit to hold in reserve should you ever need to perform this task.

Electroosmotic Haptics For More Tactile Touch Devices

May 2, 2023 by Navarre Bartz 18 Comments

If you’re like us, one of the appeals of retro tech is the tactile feedback you get from real buttons. Researchers at Carnegie Mellon have developed a new method for bringing haptic feedback to touchscreen devices.

Using an array of miniaturized electroosmotic pumps, the current prototype devices offer 5 mm of displacement from a 5 mm stackup which is a significant improvement over previous technologies which required a lot more hardware than the displacement provided. When placed under a flexible screen, notifications and other user interactions like the keyboard can raise and lower as desired.

Each layer is processed by laser before assembly and the finished device is self-contained, needing only electrical connections. No need for a series of tubes carrying fluid to make it work. Interaction surfaces have been able to scale from 2-10 mm in diameter with the current work, but do appear to be fixed based on the video (below the break).

You might find applications for haptics in VR or want to build your own Haptic Smart Knob.

Continue reading “Electroosmotic Haptics For More Tactile Touch Devices” →