Fusing Cheap EBay Find Into A Digital Rangefinder

One of the earliest commercially-successful camera technologies was the rangefinder — a rather mechanically-complex system that allows a photographer to focus by triangulating a subject, often in a dedicated focusing window, and and frame the shot with another window, all without ever actually looking through the lens. Rangefinder photographers will give you any number of reasons why their camera is just better than the others — it’s faster to use, the focusing is more accurate, the camera is lighter — but in today’s era of lightweight mirrorless digitals, all of these arguments sound like vinyl aficionados saying “The sound is just more round, man. Digital recordings are all square.” (This is being written by somebody who shoots with a rangefinder and listens to vinyl).

While there are loads of analog rangefinders floating around eBay, the trouble nowadays is that digital rangefinders are rare, and all but impossible to find for a reasonable price. Rather than complaining on Reddit after getting fed up with the lack of affordable options, [Mr.50mm] decided to do something about it, and build his own digital rangefinder for less than $250.

Part of the problem is that, aside from a few exceptions, the only digital rangefinders have been manufactured by Leica, a German company often touted as the Holy Grail of photography. Whether you agree with the hype or consider them overrated toys, they’re sure expensive. Even in the used market, you’d be hard-pressed to find an older model for less than $2,000, and the newest models can be upwards of $10,000.

Rather than start from scratch, he fused two low-cost and commonly-available cameras into one with some careful surgery and 3D printing. The digital bits came from a Panasonic GF3, a 12 MP camera that can be had for around $120, and the rangefinder system from an old Soviet camera called the Fed 5, which you can get for less than $50 if you’re lucky. The Fed 5 also conveniently worked with Leica Thread Mount (LTM) lenses, a precursor to the modern bayonet-mount lenses, so [Mr.50mm] lifted the lens mounting hardware from it as well.

Even LTM lenses are relatively cheap, as they’re not compatible with modern Leicas. Anyone who’s dabbled in building or repairing cameras will tell you that there’s loads of precision involved. If the image sensor, or film plane, offset is off by the slightest bit, you’ll never achieve a sharp focus — and that’s just one of many aspects that need to be just right. [Mr.50mm]’s attention to detail really paid off, as the sample images (which you can see in the video below) look fantastic. Continue reading “Fusing Cheap EBay Find Into A Digital Rangefinder”

Reverse Engineering A ‘Tony’ 6502-based Mini Arcade Machine

The mainboard of the mini arcade unit with its blob chip and EEPROM. (Credit: Poking Technology, YouTube)
The mainboard of the mini arcade unit with its blob chip and EEPROM. (Credit: Poking Technology, YouTube)

For some reason, people are really into tiny arcade machines that basically require you to ruin your hands and eyes in order to play on them. That said, unlike the fifty gazillion ‘retro consoles’ that you can buy everywhere, the particular mini arcade machine that [David Given] of [Poking Technology] obtained from AliExpress for a teardown and ROM dump seems to have custom games rather than the typical gaggle of NES games and fifty ROM hack variations of each.

After a bit of gameplay to demonstrate the various games on the very tiny machine with tiny controls and a tiny 1.8″, 160×128 ST7735 LC display, the device was disassembled. Inside is a fairly decent speaker, the IO board for the controls, and the mainboard with an epoxy blob-covered chip and the SPI EEPROM containing the software. Dumping this  XOR ‘encrypted’ ROM was straightforward, revealing it to be a 4 MB, W23X32-compatible EEPROM.

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A long, rectangular electronic device is shown in front of a book of colour swatches. A small LCD display on the electronic device says “PANTONE 3005 C,” with additional color information given in smaller font below this.

A Spectrophotometer Jailbreak To Resolve Colorful Disputes

The human eye’s color perception is notoriously variable (see, for example, the famous dress), which makes it difficult to standardize colours. This is where spectrophotometers come in: they measure colours reliably and repeatably, and can match them against a library of standard colors. Unfortunately, they tend to be expensive, so when Hackaday’s own [Adam Zeloof] ran across two astonishingly cheap X-Rite/Pantone RM200 spectrophotometers on eBay, he took the chance that they might still be working.

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PIC Burnout: Dumping Protected OTP Memory In Microchip PIC MCUs

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.

Diagnosing Whisker Failure Mode In AF114 And Similar Transistors

The inside of this AF117 transistor can was a thriving whisker ecosystem. (Credit: Anthony Francis-Jones)
The inside of this AF117 transistor can was a thriving whisker ecosystem. (Credit: Anthony Francis-Jones)

AF114 germanium transistors and related ones like the AF115 through AF117 were quite popular during the 1960s, but they quickly developed a reputation for failure. This is due to what should have made them more reliable, namely the can shielding the germanium transistor inside that is connected with a fourth ‘screen’ pin. This failure mode is demonstrated in a video by [Anthony Francis-Jones] in which he tests a number of new-old-stock AF-series transistors only for them all to test faulty and show clear whisker growth on the can’s exterior.

Naturally, the next step was to cut one of these defective transistors open to see whether the whiskers could be caught in the act. For this a pipe cutter was used on the fairly beefy can, which turned out to rather effective and gave great access to the inside of these 1960s-era components. The insides of the cans were as expected bristling with whiskers.

The AF11x family of transistors are high-frequency PNP transistors that saw frequent use in everything from consumer radios to just about anything else that did RF or audio. It’s worth noting that the material of the can is likely to be zinc and not tin, so these would be zinc whiskers. Many metals like to grow such whiskers, including lead, so the end effect is often a thin conductive strand bridging things that shouldn’t be. Apparently the can itself wasn’t the only source of these whiskers, which adds to the fun.

In the rest of the video [Anthony] shows off the fascinating construction of these germanium transistors, as well as potential repairs to remove the whisker-induced shorts through melting them. This is done by jolting them with a fairly high current from a capacitor. The good news is that this made the component tester see the AF114 as a transistor again, except as a rather confused NPN one. Clearly this isn’t an easy fix, and it would be temporary at best anyway, as the whiskers will never stop growing.

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Phone Keyboard Reverse Engineered

Who knows what you’ll find in a second-hand shop? [Zeal] found some old keyboards made to fit early Alcatel phones from the year 2000 or so. They looked good but, of course, had no documentation. He’s made two videos about his adventure, and you can see them below.

The connector was a cellphone-style phone jack that must carry power and some sort of serial data. Inside, there wasn’t much other than a major chip and a membrane keyboard. There were a few small support chips and components, too.

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Animal Crossing keyboard banner

Making GameCube Keyboard Controller Work With Animal Crossing

[Hunter Irving] is a talented hacker with a wicked sense of humor, and he has written in to let us know about his latest project which is to make a GameCube keyboard controller work with Animal Crossing.

This project began simply enough but got very complicated in short order. Initially the goal was to get the GameCube keyboard controller integrated with the game Animal Crossing. The GameCube keyboard controller is a genuine part manufactured and sold by Nintendo but the game Animal Crossing isn’t compatible with this controller. Rather, Animal Crossing has an on-screen keyboard which players can use with a standard controller. [Hunter] found this frustrating to use so he created an adapter which would intercept the keyboard controller protocol and replace it with equivalent “keypresses” from an emulated standard controller.

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