Upgrading At Least One Component Of A TI Calculator

January 24, 2024 by Bryan Cockfield 12 Comments

Even though Texas Instruments were the first company to produce an integrated circuit and a microprocessor, their success as a company in the 60s and 70s was not guaranteed. At the time there wasn’t much demand for previously non-existent products like these, so to drive some business they built the first hand-held calculator, a venture that they are still famous for today. Since then, though, they’ve become a bit of a punchline for producing calculators with decades-old technology but with modern price tags, so while this business model was quite successful if you want a calculator with a few modern features you’ll have to take a DIY approach like this calculator retrofitted with a LiPo battery.

The modern battery pack, with a lithium polymer battery at its core, includes all of the circuitry needed to integrate it seamlessly into the TI-59 calculator, which is all available on the project’s GitHub page. This calculator originally used a 9V battery, so the new battery pack includes a boost converter to match the 3.7V from the new battery to the needs of the old calculator. It doesn’t stop there, though. The pack is rechargeable from an included USB-C port, has a built-in charge controller, and is housed in its own custom-built case that fits neatly into the calculator where the old battery would sit.

While this wouldn’t be a drop-in replacement for more modern calculators like the TI-83/84 and TI-89, a new case and a different boost converter would solve the problem of the AAA batteries dying during exams. It might make the calculators non-compliant with various standardized testing requirements, though (which TI was also instrumental in developing) so you may want to verify with your testing standard of choice before modifying a calculator you need for an exam. But if all the rules are off, why not add Wi-Fi to it too?

Prison TV Gets Simple Speaker Mod

April 13, 2023 by Lewin Day 20 Comments

American prisons are strict about television use. Typically they’re only to be used with headphones, and their enclosures need to be transparent so they can’t be used to smuggle goods. ClearTech makes TVs that meet these specifications, and when [Steve Pietras] got his hands on just such a unit, he set about modding it for use in the free world.

Getting into the TV isn’t easy; ClearTech built the units using special security fasteners unlike any we’ve seen before. [Steve] found a way to deal with these, though declines to share his technique in his video. Once inside though, his task is relatively straightforward. He steps through where to install speakers in the TV’s housing, and how to hook them up to the right spots on the main circuit board. With the case closed back up, [Steve] is able to use the TV without headphones, and without the threat of getting shanked by a fellow inmate who really doesn’t want to hear Jeopardy while they’re trying to read.

It’s not every day we get to look at a piece of obscure hardware like this. We’d never seen a prison TV before, and now we feel like experts on the topic. Of course, we’re no strangers to esoterica at Hackaday.

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A Solari Mechanical Digital Clock Hack With A Little Extra

February 14, 2022 by Dave Rowntree 7 Comments

[Alfredo Cortellini] was perusing an antique shop in Bologna, and came across a nice example of a late 1950s timepiece, in the shape of a Solari Cifra 5 slave clock, but as the shop owner warned, it could never tell the time by itself. That sounded like a challenge, and the resulting hack is a nice, respectful tweak of the internals to bring it into the modern era. Since the clock requires a single pulse-per-minute in order to track time, the simplest track often followed is to open the back, set the correct time manually by poking the appropriate levers, and then let an external circuit take over clocking it. [Alfredo] wanted autonomy, and came up with a solution to make the thing fully adjust itself automatically.

Electronics-wise, initial prototyping was performed with a Nucleo 32 dev board and a pile of modules, before moving to a custom PCB designed in Altium Designer. An STM32G031 runs the show, with a few push buttons and a SSD1306 OLED display forming the UI.

Using some strategically-placed magnets and hall effect sensors, the status of the internal mechanism could be determined. Minute advancements were effected by driving the clock’s 24V electromagnet with a DRV8871 motor driver IC, the power supply for which was generated from the USB supply via a TPS61041 boost converter. In order to synchronise the mechanism with the electronics, the unit could have been driven to advance a minute at a time, but since every hour would need sixty pulses, this could take a while given the limited speed at which that could be done reliably. The solution was to sneak in a crafty MG996R high-torque servo motor, which pushes on the hour-advancement lever, allowing the unit to be zeroed much faster. Sensing of the zero-hour position was done by monitoring the date-advance mechanism, that is not used in this model of clock. Once zeroed, the clock could then be advanced to the correct time and kept current. Firmware source, utililising FreeRTOS can be found on the project GItHub, with schematics and Fusion360 files on the Hackaday.IO project linked above.

If you were thinking you’ve seen these Solari soft-flap displays here before, you’d be quite correct, but if you’re not so much interested in marking the passage of time, but bending such devices to your other indication whims, we’ve got you covered also.

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Adding Wireless Charging To The Switch Lite

October 13, 2021 by Tom Nardi 3 Comments

The Nintendo Switch is a monstrously popular machine, and it’s had no difficulty raking in the bucks for the Japanese gaming giant, but there’s no denying that it’s technologically a bit behind the curve. Until the long-rumored “Pro” version of the Switch materializes, industrious gamers like [Robotanv] will simply have to make up for Nintendo’s Luddite ways by hacking in their own upgraded hardware.

In this case, [Robotanv] wanted to add Qi wireless charging to his Switch Lite. He figured that if all of his other mobile devices supported the convenient charging standard, why not his portable gaming system? Luckily, the system already supports the increasingly ubiquitous USB-C, so finding an aftermarket Qi receiver that would connect to it was no problem. He just needed to install it into the handheld’s case.

After liberating the Qi receiver from its protective pouch enclosure to get it a bit thinner, [Robotanv] taped it to the inside of the system’s case and ran thin wires to the rear of the USB-C port. As luck would have it, Nintendo was kind enough to put some test pads for the power pins right behind the port, which made for an ideal spot to connect the charger.

At first he only connected the positive and negative lines from the charger, but quickly realized he also had to connect the CC pin to get the juice flowing. After that, it was just a matter of buttoning the system back up. All told, it looks like a pretty simple modification for anyone who’s not bashful about taking a soldering iron to their $199 console.

We’ve seen these Qi receivers retrofitted into devices before, and it remains an excellent way to add the feature not only to commercial products, but to your own projects.

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Exploring An Aftermarket LED Headlight Retrofit Kit

September 23, 2021 by Tom Nardi 30 Comments

There’s plenty of debate about drop-in LED headlight bulbs, especially when they’re used with older reflector housings that were designed for halogen bulbs. Whether or not you personally feel the ultra-bright lights are a nuisance, or even dangerous, one thing we can all agree on is that they’re clearly the result of some impressive engineering.

Which is why we were fascinated to see the teardown [TechChick] did on a “Ultra 2 LED” retrofit from GTR Lighting. Apparently one of the diodes was failing, and as part of the warranty replacement process, she was informed she had to make it completely inoperable. Sounds like a teardown dream come true. If a manufacturer ever told us we needed to take something apart with extreme prejudice and provide photographic evidence that the deed was done, we’d be all too happy to oblige.

The driver itself ended up being completely filled with potting compound, so she doesn’t spend much time there. Some will no doubt be annoyed that [TechChick] didn’t break out the small pointy implements and dig all that compound out, but we all pretty much know what to expect when it comes to driving LEDs. The real interesting bit is the bulb itself.

As is common with these high-output automotive LEDs, the Ultra 2 is actively cooled with a small fan that’s actually enclosed within the heatsink. With the fan and the two-piece heatsink removed, she’s able to access the LED module itself. Here, two PCBs are sandwiched back to back with a hollow copper chamber that leads out of the rear of the module. When [TechChick] cut into the copper she said she heard a hiss, and assumed it was some kind of liquid cooling device. Specifically we think it’s a vapor chamber that’s being used to pull heat away from the diodes and into the heatsink at the rear of the module, which speaks to the advanced technology that makes these bulbs possible.

While laser headlights are arguably the future of automotive lighting, it’s going to be quite some time before they trickle down to those of us that don’t own supercars. Until then, when used responsibly, these LED retrofits can inject a bit of cutting-edge tech into your old beater without breaking the bank.

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Hacked IKEA Air Quality Sensor Gets Custom PCB

August 13, 2021 by Tom Nardi 19 Comments

Last month we brought word of the IKEA VINDRIKTNING, a $12 USD air quality sensor that could easily be upgraded to log data over the network with the addition of an ESP8266. It only took a couple of wires soldered to the original PCB, and since there was so much free space inside the enclosure, you didn’t even have to worry about fitting the parasitic microcontroller; just tape it to the inside of the case and button it back up.

Now we’ve got nothing against the quick and dirty method around these parts, but if you’re looking for a slightly more tidy VINDRIKTNING modification, then check out this custom PCB designed by [lond]. This ESP-12F board features a AP2202 voltage regulator, Molex PicoBlade connectors, and a clever design that lets it slip right into a free area inside the sensor’s case. The project description says the finished product looks like it was installed from the factory, and we’re inclined to agree.

Nothing has changed on the software side, in fact, the ESP-12F gets flashed with the same firmware [Sören Beye] wrote for the Wemos D1 Mini used in his original modification. That said [lond] designed the circuit so the MCU can be easily reprogrammed with an FTDI cable, so just because you’re leaving the development board behind doesn’t mean you can’t continue to experiment with different firmware builds.

It’s always gratifying to see this kind of community development, whether or not it was intentionally organized. [lond] saw an interesting idea, found a way to improve its execution, and released the result out into the wild for others to benefit from. It wouldn’t be much of a stretch to say that this is exactly the kind of thing Hackaday is here to promote and facilitate, so if you ever find yourself inspired to take on a project by something you saw on these pages, be sure to drop us a line.

How To Modify Your Car Stereo For Bluetooth Or Aux-In

July 28, 2021 by Lewin Day 42 Comments

If you’re an automotive enthusiast of taste, you can’t stand the idea of fitting a janky aftermarket stereo into your nice, clean ride. Flashy, modern head units can spoil the look of a car’s interior, particularly if the car is a retro, classic, or vintage ride.

Thus, we’re going to look at how to modify your existing stock car stereo to accept an auxiliary cable input or even a Bluetooth module. This way, you can pump in the latest tunes from your smartphone without a fuss, while still maintaining an all-original look on the dash.

Fundamentals

A simple Bluetooth module designed for wiring into car audio systems. There are two wires for 12 V power from the vehicle, and the audio signal is sent out over the RCA plugs. The RCA plugs can be cut off and the module hard wired inside your stereo if you have room. Cutting off the plastic case can help too.

Depending on your choice of audio player, you may prefer a 3.5 mm aux jack, or you might want to go with Bluetooth audio if your smartphone no longer has a headphone port. Whichever way you go, the process of modifying the stereo is largely the same. To achieve your goal, you need to find a way of injecting the audio signal into the head unit’s amplifier stage, while making sure no other audio sources are getting sent there as well.

Whether that audio source is a 3.5 mm jack or a Bluetooth module doesn’t matter. The only difference is, in the latter case, you’ll want to buy a Bluetooth module and hardwire it in to the auxiliary input you create, while also splicing the module into the stereo’s power supply. In the case of a simple headphone jack input, you simply need to wire up an aux cord or 3.5 mm jack somewhere you can get to it, and call it done.

This guide won’t cover every stereo under the sun, of course. Edge cases exist and depending on the minute specifics of how your original car radio works, these exact methods may or may not work for you. However, this guide is intended to get you thinking conceptually about how such mods are done, so that you can investigate the hardware in front of you and make your own decisions about how to integrate an external audio input that suits your usage case. Continue reading “How To Modify Your Car Stereo For Bluetooth Or Aux-In” →