34C3: Hacking into a CPU’s Microcode

Inside every modern CPU since the Intel Pentium fdiv bug, assembly instructions aren’t a one-to-one mapping to what the CPU actually does. Inside the CPU, there is a decoder that turns assembly into even more primitive instructions that are fed into the CPU’s internal scheduler and pipeline. The code that drives the decoder is the CPU’s microcode, and it lives in ROM that’s normally inaccessible. But microcode patches have been deployed in the past to fix up CPU hardware bugs, so it’s certainly writeable. That’s practically an invitation, right? At least a group from the Ruhr University Bochum took …read more http://pje.fyi/Q81W8x

Paul Jacob Evans

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An Mbed In Your Browser

If you have dabbled in the world of ARM microcontrollers, you might be familiar with the Mbed platform, a software abstraction layer for a range of ARM-based small dev boards. If you don’t have an Mbed board but fancy giving it a go, you might imagine that you’d be out of luck, but [Jan Jongboom] could have an answer to your problem in the form of an Mbed simulation in your browser.

We’re not high-end ARM microcontroller developers here at Hackaday so beyond observing that it brings the Mbed abstraction layer binaries to the browser through the magic of Emscripten …read more http://pje.fyi/Q6RCfN

Paul Jacob Evans

Snitch On Your AC Devices With Stolen Power

Low power devices are always intriguing, as they open up possibilities for applications with the need to operate remotely, or for very long periods without attention. There are all manner of techniques for powering such devices, too, such as using solar panels, super capacitors, or other fancy devices. The Micro Power Snitch is one such device, which can report wirelessly on your AC-powered appliances.

The device is built around a tiny ARM microcontroller and an RFM69 radio module. The entire circuit is run by leeching power from an AC current transformer, wrapped around one of the power lines of an …read more http://pje.fyi/Q4kS1b

Paul Jacob Evans

Build one, get two: CPLD and STM32 development on a single board

Programmable logic devices have claimed their place in the hobbyist world, with more and more projects showing up that feature either a CPLD or their bigger sibling, the FPGA. That place is rightfully earned — creating your own, custom digital circuitry not only adds flexibility, but opens up a whole new world of opportunities. However, this new realm can be overwhelming and scary at the same time. A great way to ease into this is combining the programmable logic with a general purpose MCU system that you already know and are comfortable with. [Just4Fun] did just that with the CPLD …read more http://pje.fyi/Q11PRc

Paul Jacob Evans

Tiny Tensor Brings Machine Deep Learning to Micros

We’ve talked about TensorFlow before — Google’s deep learning library. Crunching all that data is the province of big computers, not embedded systems, right? Not so fast. [Neil-Tan] and others have been working on uTensor, an implementation that runs on boards that support Mbed-OS 5.6 or higher.

Mbed of course is the embedded framework for ARM, and uTensor requires at least 256K of RAM on the chip and an SD card less than (that’s right; less than) 32 GB. If your board of choice doesn’t already have an SD card slot, you’ll need to add one.

The project is under …read more http://pje.fyi/Q0k8Cc

Paul Jacob Evans

Global Thermonuclear War: Tweeted

[Andreas Spiess] did a video earlier this year about fallout shelters. So it makes sense now he’s interested in having a Geiger counter connected to the network. He married a prefabricated counter with an ESP32. If it were just that simple, it wouldn’t be very remarkable, but [Andreas] also reverse-engineered the schematic for the counter and discusses the theory of operation, too. You can see the full video, below.

We often think we don’t need a network-connected soldering iron or toaster. However, if you have a radiological event, getting a cell phone alert might actually be useful. Of course, if …read more http://pje.fyi/PtJzTs

Paul Jacob Evans

The Tiny, $25 PocketBone

It was announced a day or two ago, but now the PocketBone has made its first real-world appearance at the World Maker Faire in New York this weekend. This is a tiny, tiny Linux computer that’s small enough to fit on a keychain, or in an Altoids mini tin. It’s only $25 USD, and from the stock lists on Mouser and Digikey, there are plenty to go around.

The specs for the PocketBeagle are more or less exactly what you would expect from any BeagleBone. There’s an ARM Cortex-A8 running at 1GHz, 512 MB of RAM, and SD card storage. …read more http://pje.fyi/Ppzh6p

Paul Jacob Evans