Take The Minimal Pain Out Of ESP32 Programming

Perhaps without many of us realising it, our single board computers perform the task of making programming their processor or SoC a lot easier. They take care of setting the right lines or commands to put the chip in programming mode, they deal with timings, such that we simply fire our code from our dev environment without having to expend much thought. It’s not as though it’s difficult to program most microcontrollers, but there is usually a procedure to set the chip in programming mode. Tired of pressing buttons to achieve this with the ESP32, [DoganM95] took the time to create an all-in-one USB ESP32 programming board.

It’s a straightforward enough CH340C design that also has a USBC-PD chip on-board allowing powering of an attached ESP32 from PD sources. It’s all the stuff you’d find incorporated on a little dev board, without the ESP32, so while it’s nothing earth-shattering it’s also a neat and useful little addition to your arsenal. Unsurprisingly it’s not the first time someone’s created a similar board for a commercially available ESP32 module.

Inside Electronic Gain Control

Normally, if you want to control the gain of an amplifier, you’ll use a variable resistor. You know, like a volume control. But what if you want to control the amplifier’s gain with a voltage? [Engineering Prof] explains a circuit that can do this using a pair of op amps and a pair of matched JFETs.

The analysis is simple because you assume the op amps are not in saturation, so you can assume that the op amp will do what it needs to do to make the input terminals equal. The left-hand op amp has one input grounded, so the output will drive the first FET  to ensure the negative terminal is also 0V. It is easy to see that the current through R1 must then be the current through the FET, which is going to be the control voltage (which is negative) divided by R1.

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1D LED PONG, Arduino-Style

Maybe it’s just us, but isn’t it kind of amazing that in a world of pretty darn realistic games, PONG is still thrilling to play? This 1D implementation by [newsonator] is about as exciting as it gets.

It works like you’d probably expect — the light moves back and forth between the two players. Keep it in the green and you have a nice, gentle volley going. Let it hit your red LED and you’ve lost a point. But if you can push your button while your yellow LED is lit, the light speeds up tremendously until the next button press in the green.

Our only wish is that subsequent yellow-light button presses would make it speed up even more. But there are really just the two speeds with the current programming.

Inside the cool laser-cut box is an Arduino Uno and a 9V battery, plus a current-limiting resistor and the all-important buzzer. We like how [newsonator] wired up the LEDs to the Arduino by soldering them to a row of header pins and sticking that into the Arduino so it can be used in other projects down the line. We also like how [newsonator] shoved a couple of dowels through the box to ultimately support the two buttons.

Check out the intro video after the break for the overall details. The build is done over a few different short videos which follow.

Although this is pretty small, it isn’t quite the minimum viable.

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Repairing An HP Power Supply

One of the interesting things about living in modern times is that a confluence of the Internet and rapid changes in the electronics industry means that test gear that used to be astronomically priced is now super affordable. Especially if, like [Frankie Mashockie], you can do a little repair work. He picked up an HP6038A power supply for $50. We couldn’t find the original list price, but even refurbs from “professional” sources go for around $800. However, the $50 price came with a “for parts” disclaimer.

The power supply is autoranging. You usually think of that as a feature of meters. In a power supply, autoranging means the device can adjust the voltage based on load as you can see explained in the video below.

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Hackaday Podcast Episode 248: Cthulhu Clock Radio Transharmonium, Thunderscan, And How To Fill Up In Space

This week, Elliot sat down with Dan for the penultimate podcast of 2023, and what a week it was. We started with news about Voyager; at T+46 years from launch, any news tends to be bad, and the latest glitch has everyone worried. We also took a look at how close the OSIRIS-REx mission came to ending in disaster, all for want of consistent labels.

Elliot was charmed by a Cthulhu-like musical instrument, while Dan took a shine to a spark gap transmitter that’s probably on the FCC’s naughty list. Any sufficiently advanced technology is indistinguishably from magic, and we looked at the laser made possible by the magician-in-chief himself, C.V. Raman. Why would you stuff a PSU full of iron filings? Probably for the same reason you’d print fake markings on a 6502 chip. We also took a look at the chemistry and history of superglue, a paper tape reader that could lop off your arm, and rocket gas stations in space.


Grab a copy for yourself if you want to listen offline.

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Mods Turn Junk UPS Into A Long-Endurance Beast

If you’ve got a so-called uninterruptible power supply (UPS) on your system, you’re probably painfully aware that the “uninterruptible” part has some pretty serious limits. Most consumer units are designed to provide power during a black out only long enough to gracefully shut down your system. But with a few hacks like these, you can stretch that time out and turn it into a long-endurance UPS.

As many good stories do, this one starts in the trash, where [MetaphysicalEngineer] spotted an APC home office-style UPS. It was clearly labeled “broken,” but that just turned out to be a dead battery. While he could have simply replaced it with a 12-volt sealed lead-acid battery, [Meta] knew that his computer setup would quickly deplete the standard battery. A little testing showed him that a car battery would extend the run time significantly, especially if he threw in some extra cooling for the onboard inverter.

His final design uses a marine deep-cycle battery in a plastic battery box with the UPS mounted on top. The vacated battery compartment made a great place to add a cooling fan, along with a clever circuit to turn it on only when the beeper on the UPS sounds, with a bonus volume control for the annoying sound. He also added accessories to the battery box top, including a voltmeter, a USB charger, and a switched 12-volt power outlet. And kudos for the liberal use of fuses in the build; things could get spicy otherwise. The video below shows the entire build along with all the testing. [MetaphysicalEngineer] managed to triple the estimated runtime for the load he’s trying to power, so it seems like a win to us.

If your needs run more toward keeping your networking gear running through a blackout, you might want to check out this inverter-less DC UPS.

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This Week In Security: Traingate, DNS, And JMP Slides

Remember Dieselgate, the scandal where certain diesel vehicles would detect an emissions test, and run cleaner for it, “cheating” the test? Traingate may just put that one into perspective. We’ll tell the story from the beginning, but buckle up for a wild and astonishing ride. It all starts with Polish trains getting a maintenance overhaul. These trains were built by Newag, who bid on the maintenance contract, but the contract was won by another company, SPS. This sort of overhaul involves breaking each train into its components, inspecting, lubricating, etc, and putting it all back together again. The first train went through this process, was fully reassembled, and then refused to move. After exhausting all of the conventional troubleshooting measures, SPS brought in the hackers.
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