FLOSS Weekly Episode 785: Designing GUIs And Building Instruments With EEZ

This week Jonathan Bennett chats with Dennis and Goran about EEZ, the series of projects that started with an Open Source programmable power supply, continued with the BB3 modular test bench tool, and continues with EEZ Studio, a GUI design tool for embedded devices.

Continue reading “FLOSS Weekly Episode 785: Designing GUIs And Building Instruments With EEZ”

Pixel Graphics From An HD44780, By Cutting Wires

[Felipe Tavares] wasn’t satisfied with the boring default fonts on an HD44780-based display. And while you can play some clever tricks with user-defined characters, if you want to treat the display as an array of pixels, you’ve got to get out your scalpel and cut up a data line.

The hack builds on work from [MisterHW] who documented the bits going from the common display driver to the display, and suggested that by cutting the data line and sending your own bits, you could send arbitrary graphics. The trick was to make sure that they’re in sync with the display, though, which means reading the frame sync line in user code.

This done, it looks like [Felipe] has it working! If you can read Rust for the ESP32, he has even provided us with a working demo of the code that makes it work.

We can’t help but wonder if it’s not possible to go even lower-level and omit the HD44780 entirely. Has anyone tried driving one of these little LCD displays directly from a microcontroller, essentially implementing the HD44780 yourself?

Any way you slice it, this is a cool hack, and it opens up the doors to DOOM, or as [MisterHW] suggests, Bad Apple on these little displays . If you do it, we want to see it.

If your needs aren’t so exotic, the classic HD44780 display is a piece of cake to get working, and an invaluable tool in anyone’s toolbox.

Printing A Replacement Case For The ThinkPad 701c

Even among ThinkPads, which are nearly universally loved by hardware hackers and Linux tinkerers alike, the 701c is a particularly rare and desirable machine. Best known for it’s “butterfly” slide out keyboard, the IBM-designed subnotebook from the mid-1990s has gained a following all its own, with active efforts to repair and restore any surviving specimens still out in the wild.

[polymatt] has already taken on a number of 701c restoration projects, but the recent release of a 3D printable case for the vintage laptop is arguably the most impressive to date. After spending an untold number of hours with an original case and a pair of calipers, the final design has been released under the Creative Commons Attribution-NonCommercial license — in other words, you’re free to print one to spruce up your 701c, but don’t run off a stack of them and start trying to move them on Etsy.

Continue reading “Printing A Replacement Case For The ThinkPad 701c”

Digital Meter From 1973, A Teardown

[Thomas] found an interesting probable millivoltmeter with some Beckman displays. Like many instruments from that time period, this one had a lot of tobacco smoke residue inside. The display unit inside had a sticker that not only showed the company that made it, but also had their Telex number on it, another sign of the times. You can see the device in the video below.

The unit looked like a one-off made by a hobbyist or a technician but the case looked suspiciously like old Bang and Olfusen equipment. Someone in the video comments mentions it was built for the service department.

Continue reading “Digital Meter From 1973, A Teardown”

Hackaday Podcast Episode 272: Desktop EDM, Silence Of The Leaves, And The Tyranny Of The Rocket Equation

With Elliot off on vacation, Tom and Dan made a valiant effort to avoid the dreaded “clip show” and provide you with the tastiest hacker treats of the week. Did they succeed? That’s not for us to say, but if you’re interested in things like non-emulated N64 games and unnecessarily cool filament sensors, this just might be one to check out.

We also came across a noise suppressor for a leaf blower, giant antennae dangling from government helicopters, and a desktop-friendly wire EDM setup that just might change the face of machining. We waxed on about the difference between AI-generated code and just pulling routines from StackExchange, came to the conclusion that single-stage-to-orbit is basically just science fiction, and took a look at the latest eclipse from 80,000 feet, albeit a month after the fact.

Worried about attracting the Black Helicopters? Download the DRM-free MP3 and listen offline, just in case.

Continue reading “Hackaday Podcast Episode 272: Desktop EDM, Silence Of The Leaves, And The Tyranny Of The Rocket Equation”

Design Review: USB-C PD Input For Yaesu FRG7700

Today is another board from a friend, [treble], who wants to convert a Yaesu FRG7700 radio to USB-C PD power. It’s yet another review that I’ve done privately, and then realized I’ve made more than enough changes to it, to the point that others could learn from this review quite a bit. With our hacker’s consent, I’m now sharing these things with you all, so that we can improve our boards further and further.

This board’s idea is thought-out and executed well – it replaces a bespoke barrel jack assembly, and is mechanically designed to fit the screw holes and the free space inside the chassis. For USB-PD, it uses a CH32V003 coupled with FUSB302 – I definitely did help pick the latter! For mechanical reasons, this board is split into two parts – one has the USB-C port, whereas the other has the MCU and the PD PHY.

In short, this board is a PD trigger. Unlike the usual PD triggers, however, this one is fully configurable, since it has a 32-bit MCU with good software support, plus, the PD PHY is also well known and easily controllable. So, if you want special behavior like charger-power-dependent profile selection for powering a static resistance load, you can implement it easily – or, say, you can do PPS for variable voltage or even lithium ion battery charging! With a bit of extra code, you could even do EPR (28 V = 140 W power) with this board, instantly making it into a pretty advanced PD trigger, beyond the ones available on the market.

Also, the board has some PCB art, and a very handy filter to get some of the USB-C charger noise out. Let’s take a look at all of these!

Current Flow Improvements

Continue reading “Design Review: USB-C PD Input For Yaesu FRG7700”

An image of a grey plastic carrying case, approximately the size of an A5 notebook. Inside are darker grey felt lined cubbies with a mirror, piece of glass, a viewfinder, and various small printed parts to assemble a camera lucida.

Camera Lucida – Drawing Better Like It’s 1807

As the debate rages on about the value of AI-generated art, [Chris Borge] printed his own version of another technology that’s been the subject of debate about what constitutes real art. Meet the camera lucida.

Developed in the early part of the nineteenth century by [William Hyde Wollaston], the camera lucida is a seemingly simple device. Using a prism or a mirror and piece of glass, it allows a person to see the world overlaid onto their drawing surface. This moves details like proportions and shading directly to the paper instead of requiring an intermediary step in the artist’s memory. Of course, nothing is a substitute for practice and skill. [Professor Pablo Garcia] relates a story in the video about how [Henry Fox Talbot] was unsatisfied with his drawings made using the device, and how this experience was instrumental in his later photographic experiments.

[Borge]’s own contribution to the camera lucida is a portable version that you can print yourself and assemble for about $20. Featuring a snazzy case that holds all the components nice and snug on laser cut felt, he wanted a version that could go in the field and not require a table. The case also acts as a stand for the camera to sit at an appropriate height so he can sketch landscapes in his lap while out and about.

Interested in more drawing-related hacks? How about this sand drawing bot or some Truly Terrible Dimensioned Drawings?

Continue reading “Camera Lucida – Drawing Better Like It’s 1807”