Indian RISC-V Chip Is Team’s Third Successful Chip

October 3, 2020 by Al Williams 20 Comments

There was a time when creating a new IC was a very expensive proposition. While it still isn’t pocket change, custom chips are within reach of sophisticated experimenters and groups. As evidence, look at the Moushik CPU from the SHAKTI group. This is the group’s third successful tapeout and is an open source RISC-V system on chip.

The chip uses a 180 nm process and has 103 I/O pins. The CPU runs around 100 MHz and the system includes an SDRAM controller, analog to digital conversion, and the usual peripherals. The roughly 25 square mm die houses almost 650 thousand gates.

This is the same group that built a home-grown chip based on RISC-V in 2018 and is associated with the Indian Institute of Technology Madras. We aren’t clear if everything you’d need to duplicate the design is in the git repository, but since the project is open source, we presume it is.

If you think about it, radios went from highly-specialized equipment to a near-disposable consumer item. So did calculators and computers. Developing with FPGAs is cheaper and easier every year. At this rate it’s not unreasonable to think It won’t be long before creating a custom chip will be as simple as ordering a PCB — something else that used to be a big hairy deal.

Of course, we see FPGA-based RISC-V often enough. While we admire [Sam Zeloof’s] work, we don’t think he’s packing 650k gates into that size. Not yet, anyway.

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Even More Firmware In Your Firmware

October 1, 2020 by Kerry Scharfglass 13 Comments

There are many ways to update an embedded system in the field. Images can fly through the air one a time, travel by sneaker or hitch a ride on other passing data. OK, maybe that’s a stretch, but there are certainly a plethora of ways to get those sweet update bytes into a target system. How are those bytes assembled, and what are the tools that do the assembly? This is the problem I needed to solve.

Recall, my system wasn’t a particularly novel one (see the block diagram below). Just a few computers asking each other for an update over some serial busses. I had chosen to bundle the payload firmware images into the binary for the intermediate microcontroller which was to carry out the update process. The additional constraint was that the blending of the three firmware images (one carrier and two payload) needed to happen long after compile time, on a different system with a separate toolchain. There were ultimately two options that fit the bill.

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Pulse Generator Does The Job With An STM8

October 1, 2020 by Lewin Day 16 Comments

When working with hardware, whether a repair or a fresh build, it’s often necessary to test something. Depending on what you’re working with, this can be easy or a total pain if you can’t get the right signal to the right place. To eliminate this frustrating problem, [WilkoL] built a useful pulse generator for use in the lab.

[WilkoL] notes that historically, the job of generating pulses of varying length and frequency would be achieved with a smattering of 555 timers. While this is a perfectly cromulent way to do so, it was desired to take a different approach for the added flexibility modern hardware can offer. The pulse generator is instead built around an STM8 microcontroller; an unusual choice in this era, to be sure. [WilkoL] specified the part for its incredibly low cost, and highly capable timer hardware – perfect for the job.

Combined with an ST7735 TFT LCD screen, and programmed in bare metal for efficiency’s sake, the final project is installed in a project box with controls for frequency and pulse length – no more, no less. Capable of pulse lengths from 250 ns to 90 s, and frequencies from 10 mHz to 2 MHz, it’s a tool that should be comfortable testing everything from servos to mechanical counters.

Of course, if you need to get down to picosecond timescales, an avalanche pulse generator might be more your speed. Video after the break.

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ESP32 Vulnerability Affects Older Chips

September 24, 2020 by Al Williams 24 Comments

There is a scene from the movie RED (Retired, Extremely Dangerous) where Bruce Willis encounters a highly-secure door with a constantly changing lock code deep inside the CIA. Knowing the lock would be impossible to break, he simply destroyed the wall next to the door, reached through, and opened the door from the other side. We thought about that when we saw [raelize’s] hack to bypass the ESP32’s security measures.

Before you throw out all your ESP32 spy gadgets, though, be aware that the V3 silicon can be made to prevent the attack. V1 and V2, however, have a flaw that — if you know how to exploit it — renders secure boot and flash encryption almost meaningless.

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Circuit Board Origami Puts You Face-to-Face With Low-Poly Electronics

September 21, 2020 by Kristina Panos 16 Comments

Paper craft has been around almost as long as paper itself. It’s fun to mimic paper craft and origami with low-poly 3D prints, and [Stephen Hawes] wondered whether it could be done with copper-clad PCBs. Two years after the question arose, we have the answer in the form of a fantastical mask with light-up eyes. Check it out in the video below.

[Stephen] started with a model (Update: [kongorilla]’s 2012 low poly mask model from back in 2012 was the starting point for this hack) from the papercraft program Pepakura Designer, then milled out dozens of boards. Only a few of them support circuitry, but it was still quite the time-consuming process. The ATmega32U4 on the forehead along with the fold-traversing circuitry serve to light up the WS2812B eyes. Power runs up the copper tube, which doubles as a handy mounting rod to connect to the 3D printed base.

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A Big Computer Needs A Big Keyboard

September 19, 2020 by Al Williams 36 Comments

It seems like many keyboard aficionados have been gravitating towards ever smaller boards, but not [Ren]. He’s mostly completed a 433% keyboard with a whopping 450 distinct keys. Using two off the shelf PCBs and Teensy to control it all, this keyboard means you’ll never need to strain to make some awkward chord.

The PCBs have a diode matrix arrangement for 225 keys, which we would have thought was big enough. After all, a Scrabble board has 225 squares, so we assume that’s why the vendor calls them scrabbleboards. Honestly, we’re jealous someone has the desk space for this monster. We were also thinking what other sorts of switch-like sensors you could use with this board. Imagine a home system, for example, with 225 occupancy sensors, each with its own key you could easily read via USB.

There was a time when building your own keyboard of any sort would have been challenging. But now there’s a cottage industry supplying chips, switches, caps, and PCBs to those looking to craft their own custom input devices. The ready availability of 3D printers has also sparked a minor revolution in custom keyboard enclosures and keycaps.

If you’re a fan of the tiny keyboards, we’ve seen some impressive specimens that might catch your fancy. If nothing else, at least they require less soldering. Especially when they only have seven keys.

Thanks [ptkwilliams] for the tip!

Casio Computer Rebuild Puts New Wine In An Old Bottle

September 18, 2020 by Mike Szczys 8 Comments

With a glut of vintage consumer electronics available from eBay it should be easy to relive your glory days, right? Unfortunately the march of time means that finding gear is easy but finding gear that works is not. So was the case when [Amen] acquired not one, but two used calculator/computer units hoping to end up with one working device. Instead, he went down the rabbit hole of redesigning his own electronics to drive the Casio QT-1 seen here.

Especially interesting is the prototyping process for the replacement board. [Amen] used a “BluePill” STM32 microcontroller board at its heart, and used point-to-point soldering for the rest of the circuitry on a rectangle of protoyping board. That circuit is non-trivial, needing a 23 V source to drive the original VFD from the computer, a battery-backed real-time-clock (MCP7940), and a GPIO expander to scan the keys on the keypad.

It worked great, but couldn’t be cut down to fit in the case. The solution was a PCB designed to fit the footprint of the original. The modern guts still need more firmware work and a couple of tweaks like nudging that 23 V rail a bit higher to 26 V for better brightness, but the work already warrants a maniacal cry of “It’s Alive!”.

This isn’t [Amen’s] first rodeo. Back in March we looked in on another vintage Casio refurb that sniffed out the display protocol.