Release Less Magic Smoke, With A Bulb Limiter

January 8, 2023 by 29 Comments

As electronics have moved lower in voltage, it’s perhaps less common to work on live-mains equipment. Thus particularly among younger hardware hackers it sometimes seems as though such work is viewed as so dangerous as to be only for the foolhardy. In practice it remains safe, so long as appropriate precautions are taken and a few pieces of useful safety equipment are present. One of those mains bench essentials is something less common in 2022, a mains current limiter using a set of switched incandescent light bulbs. [Donna LaRocco] shares a modern take on the idea, incorporating a digital mains voltmeter.

The idea is that a mains device under test is connected in series with a light bulb of a suitable wattage to let through enough current to run the device in normal operation, but to light up and bring down the voltage if the device draws too much. It’s an extremely simple but effective tool. Traditionally these are built using household electrical fittings on a board, and this one is no exception. The voltmeter comes from the RV market where voltage drop is an issue, no doubt giving European readers a chance to chuckle with their 230 V outlets.

If mains safety needs your attention, it’s a subject we’ve addressed in the past.

Classic Video Chip Drives A Modern TFT

January 7, 2023 by 11 Comments

A lot of us have a soft spot for retrocomputers, and there’s nothing quite like running original hardware. Unfortunately if you’re after the truly original touch then that means carrying along the family TV from 1982, and that’s where life becomes annoying. What if there were a way you could easily drive an LCD panel from a classic video controller? Help is at hand for owners of TI TMS9928A video chips, courtesy of [umaker], with a clever interface board that drives an SPI or parallel TFT.

At its heart is not the FPGA you might expect, but an STM32G4 microcontroller on an STM Nucleo board. This digitizes the R-Y and Y components from the TMS chip which would originally have been destined for an NSC or PAL encoder, does the color conversion through its algorithm, and transfers the result to the screen. This is a task which would back in the day when NTSC or PAL were king have been seen as extremely computationally intensive, so it’s a mark of just how capable an STM can be that a few dollar microcontroller can do it.

We can see this technique proving to be extremely useful across a lot of different retro color graphic applications. We’re not sure whether its lag would be too much for a light gun game, but it would be nice to think that it would result in handheld retro machines.

We encountered this project previously, when as part of its development he needed a sync separator.

Tiny Robots That Bring Targeted Drug Delivery And Treatment A Little Bit Closer

January 7, 2023 by 8 Comments

Within the world of medical science fiction they are found everywhere: tiny robots that can zip through blood vessels and intestines, where they can deliver medication, diagnose medical conditions and even directly provide treatment. Although much of this is still firmly in the realm of science-fiction, researchers at Stanford published work last year on an origami-based type of robots, controlled using an external magnetic field. Details can be found in the Nature Communications paper. Continue reading “Tiny Robots That Bring Targeted Drug Delivery And Treatment A Little Bit Closer” →

Gorgeous Sunflower Macropad Will Grow On You

January 7, 2023 by 3 Comments

Once [Hide-key] saw the likes of the banana and corn macro pads, they knew they had to throw their hat in this strange and wonderful ring. Some family members suggested a sunflower, and off they went looking for inspiring images, finally settling on a more iconic and less realistic design which we think is quite beautiful.

This lovely little macro pad has seven keys hiding under those petals, with the eighth major petal concealing a XIAO RP2040 microcontroller. The rest of the major petals actuate a low-profile Kailh choc in — what else? — brown. Don’t worry, the middle isn’t a wasteland — there’s a low-profile rotary encoder underneath. Part of the reason this flower looks so great is that [Hide-key] started with SLA prints, but the paint choices are aces as well. If you’d like to grow your own sunflower, everything about this garden is open-source.

Oh yes, we totally covered the banana and the banana split, though we must have missed out on the corn. We hear that when you try it with butter, everything changes.

Via KBD #109

Wireless CNC Pendant Implemented With ESP-NOW

January 7, 2023 by 6 Comments

As a fervent fan of twiddly and twirly widgets and tactile buttons in a device’s user interface, [Steve M Potter] created a remote control (pendant) for his CNC machine, which he explains in a recent video that’s also linked down below. In addition to all the tactile goodness, what is perhaps most interesting about this controller is that it uses Espressif’s ESP-NOW protocol. This still uses the same 2.4 GHz as WiFi would, but uses a system more akin to the pairing of a wireless mouse or keyboard.

Advantages of ESP-NOW include the lower power usage, longer range, no requirement for a router and WiFi SSID & password. As far as latency goes, [Steve] measured a round-trip latency of 2.4 ms, which is fast enough for this purpose. Since it does control a potentially dangerous machine, all transmissions are acknowledged and re-transmitted at higher power if needed.

The lower power usage means that the pendant will last a lot longer on a single charge from the 18650 Li-ion cell, while ESP-NOW’s fixed address pairing saves time when turning the pendant on. Meanwhile, on the CNC side, another ESP32 acts as the receiving end for commands, although theoretically an ESP8266 could be used as well, if size or power was a concern there.

As for the transparent enclosure? It’s to make it easier to show it off to interested folk, apparently.

Continue reading “Wireless CNC Pendant Implemented With ESP-NOW” →

New Part Day: ESP32-P4 Espressif RISC-V Powerhouse

January 7, 2023 by 63 Comments

It seems every day there’s a new microcontroller announcement for which the manufacturer is keen to secure your eyeballs. Today it’s the turn of Espressif, whose new part is the ESP32-P4, which despite being another confusingly named ESP32, is a high-performance addition to their RISC-V line-up.

On board are dual-core 400 MHz and a single-core low power 40 MHz RISC-V processors, and an impressive array of hardware peripherals including display and camera interfaces and a hardware JPEG codec alongside the ones you’d expect from an ESP32 part. It’s got a whopping 768 KB of on-chip SRAM as well as 8 K of very fast cache RAM for intensive operations.

So after the blurb, what’s in it for us? It’s inevitable that the RISC-V parts will over time displace the Tensilica parts over time, so we’ll be seeing more on this processor in upcoming Hackaday projects. We expect in particular for this one to be seized upon by badge developers, who are intent on pushing extra functionality out of their parts.So we look forward to seeing the inevitable modules with this chip on board, and putting them through their paces.

Thanks [Renze] for the tip.

Happy New Year, Hackaday!

January 7, 2023 by 4 Comments

[Tom Nardi] and I were talking on the podcast about 2022, and how it went from the hacker’s perspective. As the global chip shortage entered its second full year, we both thought back on the ways that we all had to adapt and work around the fact that we just couldn’t get the parts we were accustomed to picking up with ease.

What had previously been an infinite supply of knockoff Arduino clones and STM32 Blue Pill boards all of a sudden just dried up. Sometimes you just couldn’t get the DAC chip you wanted, or at least not without many weeks’ lead time, and even then, it’d cost you. Raspberry Pi single-board computers became hard to find. PCB designs had to change and new SDKs needed to be learned. I know I had to grab twice for unfamiliar microcontroller platforms this year.

We hacked around the problems. It would be absurd to say that the chip shortage wasn’t a pain in the posterior, but in the end we all managed to carry on and keep creating. We created more flexible footprints, learned to design around what we could get, and definitely had to do more planning. We pulled parts for projects out of the junk box or shelf stock. Or, as Tom noted, we did what everyone in the parts of the world who aren’t as fortunate to get free expedited shipping does – we made do.

Making do often meant learning new environments, questioning old habits, and double-checking pinouts. But if you’re like me, not all of that time was wasted. Sometimes it’s good to get shaken out of comfy workflows, even if by force. So while we wish you parts-in-stock and easy availability for 2023, don’t forget the lessons learned from 2022. Stay scrappy, Hackaday!

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