How not to build a semiconductor lapping machine

electronupdate writes:

One area of silicon reverse engineering which has interested me is the delayering of a chip to see each layer which allows superior visibility into the circuitry. I know of two ways: chemical etch and mechanical means.
In this video I try to make a mechanical grinder which can take micron levels of material away: a partial success. Parts are ground but I was not able to keep the silicon absolutely flat. More study of the commercial units is warranted!

See the full post on electronupdate blog.

Attiny85 pogo backpack programmer


Facelesstech published a new build:

So you are using a bare attiny85 in your next project but don’t have room for the programming header, What do you do? I came up with the idea of using pogo pins layed out on A PCB so that they will sit on top of the Attiny85 legs. I used standard male jumps at each end of the chip to help line it up.

More details on Facelesstech homepage. Project files are available at Github.

Check out the video after the break.

HP 8566B Spectrum Analyzer “YTO unlock” repair


Kerry Wong did a repair of an HP 8566B Spectrum Analyzer “YTO unlock” and documented the repair process on his blog:

While I was making a video on how to use HP 8671A as the frequency reference for an improved version of my simple DIY tracking generator for my HP 8566B spectrum analyzer, my spectrum analyzer suddenly decided to call it quits and displayed the dreaded “YTO Unlock” message. Although it wasn’t the first time it had done so — other times the “YTO Unlock” message only appeared once in a blue moon and rarely affected any measurements — this time however the problem seemed to be permanent and the error message wouldn’t go away.

Check out the video after the break.

App note: Avoidance of ceramic-substrate-based LED chip cracking induced by PCB bending or flexing


Application note from CREE on the causes of ceramic-substrate-based failures due to PCB board stresses and how to minimize their occurrence. Link here (PDF)

Printed circuit board (PCB) bending and/or flexing is an unavoidable phenomenon that is known to exist and is easily encountered during electronic board assembly processes. PCB bending and/or flexing is the fundamental source of tensile stress induced on the electronic components on the board assembly. For more brittle components, like ceramic-based electronic components, micro-cracks can be induced, which can eventually lead to a fatal failure of the components. For this reason, many standards organizations throughout the world specify the methods under which electronic board assemblies must be tested to ensure their robustness, sometimes as a precondition to more rigorous environmental tests such as thermal cycling or thermal shock.

App note: Power management solution – Constant Voltage (CV) pulse charging of hybrid capacitors


App note from Vishay about constant voltage (CV) pulse charging as the most cost-efficient solution to use on Hyrid capacitors. Link here (PDF)

Rechargeable energy storage solutions are of high interest because of their flexibility, low maintenance requirements, and reduced cost over their life-cycle.

For compact applications, classic electrolytic capacitors are environmentally friendly alternatives and available for a wide range of rated voltages. However, they soon reach their energy storage limit with output requirements exceeding a few 100 mWs.

Electric double-layer capacitors (EDLC) offer high power and energy density, as well as long working life, but are limited to low working voltages in the same range as batteries. Electronic systems require a compromise between these technologies, namely solutions that combine the advantages of classic batteries and double-layer capacitors without the limitations.


Using DC motors to power computers


Electric generator experiment from HomoFaciens:

The generators I am using are in fact geared DC motors, left over from a project with my sponsor RS Components. The modern abacuses being powered during my experiments are a Raspberry Pi Model, a SIMATIC IOT2020 and an Arduino Uno. A 2×16 characters LCD is used to display results. Two geared DC motors are on my board with the test setup

More info at

Check out the video after the break.



Stylophone business card project from

Printed Circuit Boards as a business card are a great gimmick. I’d seen ones with USB ports etched into them, which enumerate as a keyboard and then type a person’s name or load up their website. It’s just about possible to build them cheap enough to hand out as a business card, at least if you’re picky about who you give them to.
A couple of years ago I took a stab at making one for myself, but I didn’t want it to be pointless. I wanted it to do something useful! Or at least entertain someone for longer than a few seconds. I can’t remember quite how I got the idea of making a MIDI-stylophone, but the idea was perfect.

More info at

Check out the video after the break.

Raspberry Pi virtual floppy for ISA (PC XT/AT) computers


Dr. Scott M. Baker wrote an article detailing how he turned a Raspberry Pi into a virtual storage device for ISA bus computers:

I’m tired of carrying compact flash cards and/or floppies back and forth to my XT computer. I like to do development at my desk using my modern windows PC. While I can certainly use a KVM switch to interact with the retro computer from my Windows desktop, it would be a lot more convenient if I could also have a shared filesystem. There are several alternatives, from serial port solutions, to network adapters. However, I wanted something that would emulate a simple disk device, like a floppy drive, something I could even boot off of, so I implemented a virtual floppy served from a Raspberry pi.

See the full post on his blog here.

Check out the video after the break.

LoRa module in DIL form


Mare writes:

Murata produces LoRa module CMWX1ZZABZ-xxx based on SX1276 transceiver and STM32L072CZ microcontroller. The soldering of the LGA module is not very hobby-friendly. I constructed small breakout PCB for this module with additional buck/boost switcher and place for SMA connector. The transceiver features the LoRa®long-range modem, providing ultra-long-range spread spectrum communication and high interference immunity, minimizing current consumption. Since CMWX1ZZABZ-091 is an “open” module, it is possible to access all STM32L072 peripherals such as ADC, 16-bit timer, LP-UART, I2C, SPI and USB 2.0 FS (supporting BCD and LPM), which are not used internally by SX1276.

More details on Mare & Gal Electronics site. Project files are available at Github.