Microcontrollers

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The Open-Source Multimeter: The HydraMeter

Designing An Open Source Multimeter: The HydraMeter

July 20, 2025 by 6 Comments

Our hacker [John Duffy] wrote in to let us know about a video he put together to explain the design of his open-source multimeter, the HydraMeter.

If you’re interested in how the circuitry for a voltmeter, ohmmeter, or ammeter might work, this video is a masterclass. In this long and detailed video, [John] walks us through his solutions to various challenges he had while designing his own multimeter. We covered this multimeter last year, and this new video elaborates on the design of the HydraMeter which has been a work in progress for years now.

Continue reading “Designing An Open Source Multimeter: The HydraMeter” →

One ROM to rule them all.

Software Defined Retro ROMs

July 19, 2025 by 6 Comments

Here’s something fun from our hacker [Piers]: Software Defined ROMs.

In this series of three videos, [Piers] runs us through what a software defined ROM is, how to make them, and then how to use them.

As [Piers] explains, one frustration a retro technician will face is a failed ROM chip. In the era he’s interested in, there are basically three relevant kinds of ROM chip, all 24-pin Dual Inline Package (DIP):

  • 2364 ROM chip: 8KB; 1x chip-select line
  • 2332 ROM chip: 4KB; 2x chip-select lines
  • 2316 ROM chip: 2KB; 3x chip-select lines

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ESP32 Plugs In To Real-Time Crypto Prices

July 17, 2025 by 7 Comments

In today’s high-speed information overload environment, we often find ourselves with too much data to take in at once, causing us to occasionally miss out on opportunities otherwise drowned out in noise. None of this is more evident in the realm of high-speed trading, whether it’s for stocks, commodities, or even crypto. Most of us won’t be able to build dedicated high speed connections directly to stock exchanges for that extra bit of edge over the other traders, but what we can do is build a system that keys us in to our cryptocurrency price of choice so we know exactly when to pull the trigger on a purchase or sale.

[rishab]’s project for doing this is based on an ESP32 paired with a 10″ touchscreen display. It gathers live data from Binance, a large cryptocurrency exchange that maintains various pieces of information about many digital currencies. [rishab]’s tool offers a quick, in-depth look at a custom array of coins, with data such as percentage change over a certain time and high and low values for that coin as well. The chart updates in real time, and [rishab] also built a feature in which scales coins up if they have been seeing large movements in price over short timeframes.

Although it’s not a direct fiber link into an exchange, it certainly has its advantages over keeping this information in a browser window on a computer where it could get missed, and since it’s dedicated hardware running custom firmware it can show you exactly what you need to see if you’re day trading crypto. Certainly projects like this are in the DIY spirit that crypto enthusiasts tout as ideals of the currency, and as people move away from mining and more into speculative trading we’d expect to see more projects like this.

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Improved Jumping Bean

2025 One Hertz Challenge: Building A Better Jumping Bean

July 17, 2025 by 4 Comments

Do you feel nostalgia for a childhood novelty toy that had potential but ultimately fell short of its promise? Do you now have the skills to go make a better version of that toy to satisfy your long-held craving? [ExpensivePlasticCrap] does and has set off on a mission to make a better jumping bean.

Jumping beans, the phenomenon on which the novelty of [ExpensivePlasticCrap]’s childhood is based, are technically not beans, and their movement is arguably not a jump — a small hop at best. The trick is that the each not-a-bean has become the home to moth larvae that twitches and rolls on the ground as the larvae thrash about, trying to move their protective shells out of the hot sun.

The novelty bean was a small plastic pill-like capsule with a ball bearing inside what would cause the “bean” to move in unexpected ways as it rolled around. [ExpensivePlasticCrap]’s goal is to make a jumping bean that lives up to its name.

Various solenoids and motors were considered for the motion component of this new and improved bean. Ultimately, it was a small sealed vibrating motor that would be selected to move the bean without getting tangled in what was to become a compact bundle of components.

An ATtiny microcontroller won out over discrete components for the job of switching the motor on and off (once per second), for ease of implementation. Add this along with a MOSFET, battery and charging board for power into a plastic capsule, and the 1  Hz jumping bean was complete.

[ExpensivePlasticCrap] offers some thoughts on how to get more jump out of the design by reducing the weight of the build and giving it a more powerful source of motion.

If insect-inspired motion gets you jumping, check out this jumping robot roach and these tiny RoboBees.

2025 Hackaday One Hertz Challenge

Pulling At Threads With The Flipper Zero

July 15, 2025 by 13 Comments

Gone are the days when all smart devices were required an internet uplink. The WiFi-enabled IoT fad, while still upon us (no, my coffee scale doesn’t need to be on the network, dammit!) has begun to give way to low-power protocols actually designed for this kind of communication, such as ZigBee, and more recently, Thread. The downside of these new systems, however, is that they can be a bit more difficult in which to dabble. If you want to see just why your WiFi-enabled toaster uploads 100 MB of data per day to some server, you can capture some network traffic on your laptop without any specialized hardware. These low-power protocols can feel a bit more opaque, but that’s easily remedied with a dev board. For a couple of dollars, you can buy Thread radio that, with some additional hacking, acts as a portal between this previously-arcane protocol and your laptop — or, as [András Tevesz] has shown us, your Flipper Zero.

He’s published a wonderful three-part guide detailing how to mod one such $10 radio to communicate with the Flipper via its GPIO pins, set up a toolchain, build the firmware, and start experimenting. The guide even gets into the nitty-gritty of how data is handled transmitted and investigates potential attack vectors (less worrying for your Thread-enabled light bulb, very worrying for your smart door lock). This project is a fantastic way to prototype new sensors, build complicated systems using the Flipper as a bridge, or even just gain some insight into how the devices in your smart home operate.

In 2025, it’s easier than ever to get started with home automation — whether you cook up a solution yourself, or opt for a stable, off-the-shelf (but still hackable) solution like HomeAssistant (or even Minecraft?). Regardless of the path you choose, you’ll likely wind up with devices on the Thread network that you now have the tools to hack.

fume extractor

Solder Smarts: Hands-Free Fume Extractor Hack

July 9, 2025 by 8 Comments

[Ryan] purchased a large fume extractor designed to sit on the floor below the work area and pull solder fumes down into its filtering elements. The only drawback to this new filter was that its controls were located near his feet. Rather than kicking at his new equipment, he devised a way to automate it.

By adding a Wemos D1 Mini microcontroller running ESPHome, a relay board, and a small AC-to-DC transformer, [Ryan] can now control the single push button used to cycle through speed settings wirelessly. Including the small transformer inside was a clever touch, as it allows the unit to require only a single power cable while keeping all the newfound smarts hidden inside.

The relay controls the button in parallel, so the physical button still works. Now that the extractor is integrated with Home Assistant, he can automate it. The fan can be controlled via his phone, but even better, he automated it to turn on by monitoring the power draw on the smart outlet his soldering iron is plugged into. When he turns on his iron, the fume extractor automatically kicks in.

Check out some other great automations we’ve featured that take over mundane tasks.

PIC Burnout: Dumping Protected OTP Memory In Microchip PIC MCUs

July 9, 2025 by 8 Comments

Normally you can’t read out the One Time Programming (OTP) memory in Microchip’s PIC MCUs that have code protection enabled, but an exploit has been found that gets around the copy protection in a range of PIC12, PIC14 and PIC16 MCUs.

This exploit is called PIC Burnout, and was developed by [Prehistoricman], with the cautious note that although this process is non-invasive, it does damage the memory contents. This means that you likely will only get one shot at dumping the OTP data before the memory is ‘burned out’.

The copy protection normally returns scrambled OTP data, with an example of PIC Burnout provided for the PIC16LC63A. After entering programming mode by setting the ICSP CLK pin high, excessively high programming voltage and duration is used repeatedly while checking that an area that normally reads as zero now reads back proper data. After this the OTP should be read out repeatedly to ensure that the scrambling has been circumvented.

The trick appears to be that while there’s over-voltage and similar protections on much of the Flash, this approach can still be used to affect the entire flash bit column. Suffice it to say that this method isn’t very kind to the Flash memory cells and can take hours to get a good dump. Even after this you need to know the exact scrambling method used, which is fortunately often documented by Microchip datasheets.

Thanks to [DjBiohazard] for the tip.