Gutting And Rebuilding A Classic Watch

No, that watch isn’t broken. In fact, it’s better.

[Lukas] got so used to his binary-readout ez430 Chronos watch that when the strap disintegrated he had to build his own to replace it. But most DIY wristwatches are so clunky. [Lukas] wanted something refined, something small, and something timeless. So he shoe-horned some modern components, including an MSP430, into a Casio F-91W watch.

The result is a watch that tells time in binary, has a built-in compass, and with some more work will be updatable through an IR receiver that he also managed to fit in there somehow. Now he has the watch that Casio would make today, if fashion had stayed stuck firmly in the early 1990s. (Or not. Apparently, Casio still makes and sells the F-91W. Who knew?)

Anyway, back to an epic and pointless hack. Have a look at the tiny, tiny board that [Lukas] made. Marvel in the fact that he drove the original LCD screen. Dig the custom Kicad parts that match the watch’s originals. To get an accurate fit for the case, [Lukas] desoldered the piezo buzzer contact and put the board onto a scanner, which is a great trick when you need to get accurate dimensions. It’s all there, and well-documented, in his GitHub, linked above.

All in all, it’s an insane hack, but we love the aesthetics of the result. And besides, sometimes the hacking is its own reward.

Battery Backup For The Raspberry Pi

You can go to any dollar store, gas station, big box store, or your favorite Internet retailer and get a USB power bank. It’s a lithium battery mashed into a plastic enclosure with a USB port, probably poorly engineered, but it does serve as a great power supply for the Raspberry Pi. For the Raspberry Pi Zero contest we’re running over on, [Patrick] built a lithium phosphate battery pack that’s much better engineered and has some features a simple USB power bank will never have.

Battery[Patrick]’s Raspberry Pi UPS isn’t just a battery and charge controller attached to the power rails; this board has a microcontroller that has full control over when the Pi wakes up, when the Pi goes to sleep, and can put the Pi into a clean shutdown, even in headless mode. SD cards around the world rejoiced.

The electronics for this project are just a low-power MSP430 microcontroller and a boost regulator. The battery pack/power manager attaches to the Pi through the first few GPIO pins on the Pi’s 40-pin header. That’s enough to tap into the 3.3 and 5V supplies, along with the serial console so power events can be scripted on the Pi.

So far, [Patrick] has made a few time-lapse movies with his lithium battery backup, a Pi Model A+, and a Raspberry Pi camera. He managed to take 99 pictures over the course of about 24 hours, powered only by a single lithium-ion cell. You can check that video out below.

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The Newest Graphing Calculator Game

Certainly everyone remembers passing time in a boring high school class playing games on a graphing calculator. Whether it was a Mario-esque game, Tetris, or BlockDude, there are plenty of games out there for pretty much all of the graphing calculators that exist. [Christopher], [Tim], and their colleagues from Cemetech took their calculator game a little bit farther than we did, and built something that’ll almost surely disrupt whatever class you’re attempting to pay attention in: They built a graphing calculator whac-a-mole game.

This game isn’t the standard whac-a-mole game, though, and it isn’t played on the calculator’s screen. Instead of phyiscal “moles” the game uses LEDs and light sensors enclosed in a box to emulate the function of the moles. In order to whack a mole, the player only needs to interrupt the light beam which can be done with any physical object. The team made extensive use of the ArTICL library which allows graphing calculators to interface with microcontrollers like the MSP432 that they used, and drove the whole thing with a classic TI-84.

This project is a fun way to show what can be done with a graphing calculator and embedded electronics, and it was a big hit at this past year’s World Maker Faire. Calculators are versatile in other ways as well. We’ve seen them built with open hardware and free software, And we’ve even seen them get their own Wi-Fi.

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VFD 430 Clock, NYC Style

[Daniel] seems to have a lot of time on his hands for building clocks, and that’s fine by us. For his latest build, he used a vacuum fluorescent display (VFD) to display hours, minutes, and seconds using an MSP430 to drive it.

Like the analog meter clock he built recently, there is no RTC. Instead, [Daniel] used the 430’s watchdog timer to generate 1Hz interrupts from the 430’s 32KHz clock. [Daniel] wanted to try Manhattan-style board construction for this project, so he built each module on a punch-cut stripboard island and super glued them to a copper-clad board. We have to agree with [Daniel] that the bare-bones construction is a nice complement to the aesthetic of the VFD.

[Daniel] set out to avoid using a VFD display driver, but each of the segments require +50V. He ran through a couple of drawing board ideas, such as using 17 transistors to drive them all before eventually settling on the MAX6921 VFD driver. The +50V comes from an open-loop boost converter he built that steps up from 12V.

The time is set with two interrupt-triggering buttons that use the shift register example from TI as a jumping off point. All of the code is available on [Daniel]’s site. Stick around after the break for a quick demo of the clock.

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Web Connected Breathalyser with Phone Display

[spillsman] is working on a IoT startup and wanted to work and play while he tested their hardware. His company, WifiThing, is bundling the Texas Instruments toolchain and mesh networking with a sort of plug-and-play web interface. The board uses a MSP430 and two other TI Networking chips to make setting up, logging data, and controlling outputs simpler. The web interface looks interesting, but in our experience this sort of approach only saves time up to a point. Then it’s time to pull out the chip’s various bibles, ‘nomicons, spell manuals, and supporting religious documents to get the thing to work.

Though, there are some projects where you would like a simple way to log data from multiple sensors, if this can do that easily (and more importantly, cheaply) it might be very cool. We are interested to see if the open source software is easy to integrate without buying their hardware. Either way, after setting up a simple circuit to heat the coil in the breathalyzer, and translate the data into a signal usable for the chip, [spillsman] was able to record alcohol levels and even keep a, perhaps unwise to record, high-score from his phone.

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Current meter shows current time

This isn’t the first of its type, but [Daniel]’s MSP430 based Analog Gauge Clock certainly ticks off the “hack” quotient. He admits an earlier Voltmeter Clock we featured a while back inspired him to build his version.

[Daniel] was taking an Embedded systems class, and needed to build an MSP430G2553 microcontroller based final project. Which is why he decided to implement the real time clock using the micro-controller itself, instead of using an external RTC module. This also simplified the hardware used – the microcontroller, a crystal, three analog ammeters, and a few passives were all that he needed. Other than the Ammeters, everything else came from his parts bin. Fresh face plates were put on the ammeters, and the circuit was assembled on a piece of strip board. A piece of bent steel plate served as the housing.

The interesting part is the software. He wrote all of it in bare C, without resorting to using the Energia IDE. He walks through all of the important parts of his code on his blog post. Setting load capacitance for the timing crystal was important, so he experimented with an oscilloscope to see which value worked best. And TI’s Application Note on MSP430 32-kHz Crystal Oscillators (PDF) proved to be a useful resource. Three PWM output’s run the three ammeters which indicate hours, minutes and seconds. Push-button switches let him set the clock. See a short demo of the clock in the video below.

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A Wooden Based, CD Stepper Scribbler

[Rohit Gupta] is back with a plotter made from scrap CD drives and an old RC servo. [Rohit] is working on hacks to create CNC machines and sharing his activities with the world. His CNC design calls for salvaged stepper motors so he first built a device for testing them. You’ve got to admire his use of the language. He named his plotter project ‘Sketchy’ and his motor tester is called ‘Easy Peasy’.

sketchyAfter finding some CD drives at the scrap pile he tore them down to test with Easy Peasy. The raw materials for the frame came from a wooden crate for an AC unit but he didn’t just start cutting it up. Nope, first he created plans with CAD; now that’s a hack you have to admire.

With the steppers tested working, and the base build under way he moved onto the control system. Originally the hardware was demonstrated using an MSP430. This worked, but a flaw in the hardware design was found. With the pen attached directly to the servo horn, it would draw a long line when being rotated away from the drawing position.

The fix is a replacement servo setup which lifts the pen up instead of rotating it. But that showed that the drawing surface wasn’t smooth. The pen kept missing places or getting caught and destroyed. The use of a spring loaded pen solved this issue. Success!

One further change migrated away from the MSP430 in favor of an Arduino Pro Mini in order to use a GRBL library instead of the g-code generator which was performing questionably. Since he likes Hackaday so much one of his first attempts with the final version of Sketchy was our logo, shown in the video after the break.

When we last saw [Rohit] he had created a fancy PCB ruler to measure components.

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