Describing a 7-segment LCD display as "high definition" is a new reach in Chinese manufacturer's product description antics, I think.

#wtf #Chinesium #HighDef #HD #LCD #7Segment #7SegmentLCDDisplay #marketing #BS

#TechnologyConnections lästert über die #7Segment-#Glühbirne:

"The Numitron: An obvious idea that wasn't very bright"
https://www.youtube.com/watch?v=YGT1EvmDJh4

#Numitron #Display #YouTube

TIL: Es gab früher Uhren mit mechanischen(!) 7-Segment-Anzeigen, die die Segmente durch mechanische Blenden ein und aus geschaltet haben:

"Digital Clock Or Automaton?"
https://www.youtube.com/watch?v=TANe2d0VTGQ

#7Segment #YouTube #Retro

SMT Part Counter Aims to Ease Taking Inventory

[Nick Poole] has an interesting idea for a new tool, one that has the simple goal of making accurate part counts of SMT reels as easy as pulling tape through a device. That device is the BeanCounter, an upcoming small handheld unit of his own design that counts parts as quickly as one can pull tape through a slot. The device is powered by a CR2032 cell and and works with 8 mm wide tapes up to 2 mm in height, which [Nick] says covers most 0805 or smaller sized parts, as well as things like SOT-23 transistors.

Why would one want to make such a task easier? Two compelling reasons for such a tool include: taking inventory of parts on partial reels or cut tape, and creating segments that contain a known number of parts.

The first is handy for obvious reasons, and the second is useful for things like creating kits. In fact, the usefulness of this tool for creating tape segments of fixed length is perhaps not obvious to anyone who hasn't done it by hand. Sure, one can measure SMT tape with a ruler or a reference mark to yield a segment containing a fixed number of parts, but that involves a lot of handling and doesn't scale up very well. In fact, the hassle of cutting tape segments accurately and repeatedly is a common pain point, so making the job easier has value.

If you looked at the photos and suspected that the big, 7-segment numeric display is done with clever PCB fabrication options (making segments by shining LEDs through PCB layers, a trick we always like to see) you're not alone. After all, [Nick] has a lot of experience in getting clever with board fabrication, and eagle-eyed readers may even suspect that the reset and setup buttons on the edge of the tool are created by using flex PCB segments as switches. Want the nitty-gritty details? Visit the GitHub repository for the project and see it all for yourself at the CAD level.

#crowdfunding #toolhacks #7segment #crowdsupply #inventory #kitproduction #smtreel #smttape #tools

Remoticon 2021 // Joey Castillo Teaches Old LCDs New Tricks

Segmented liquid crystal displays are considered quite an old and archaic display technology these days. They're perhaps most familiar to us from their use in calculators and watches, where they still find regular application. [Joey Castillo] decided that he could get more out of these displays with a little tinkering, and rocked up to Remoticon 2021 to share his findings.

[Joey's] talk is a great way to learn the skills needed to reverse engineer a typical segment LCD.[Joey] got his start hacking on these displays via his Sensor Watch project - a board swap for the venerable Casio F-91W wristwatch, with the project now available on CrowdSupply. It kits out the 33-year-old watch design with a modern, low-power ARM Cortex M0+ microcontroller running at 32 MHz that completely revolutionizes what the watch can do. Most importantly, however, it repurposes the watches original segmented monochrome LCD.

Segment LCDs are usually small monochrome devices made out of glass, that have the benefit of using very little power in their operation. They come with a fixed layout, which cannot be changed - so they're often designed specifically for a given purpose. A calculator will have segments laid out to display numbers, often in the usual 7-segment fashion, while a watch may add dedicated segments for displaying things like "AM," "PM," or "ALARM."

Their purpose-built nature means they're often very thin and compact with useful layouts that are attractive and fitting for their given applications. Compared to general purpose LCDs, like the popular HD44780 character LCDs, they often have much cleaner aesthetics and a sleeker design as they're meant to be consumer-facing, rather than used in any one of a million different industrial applications.

[Joey's] talk starts off with a primer on how segment LCDs work, initially comparing them to 7-segment LEDs that so many of us are familiar with. However, LCDs are a little different in their operation, with segments darkening when a voltage differential exists, and are driven with AC signals rather than DC. [Joey] explains how to drive LCD segments in this manner, providing a CircuitPython example that demonstrates how its done.

Multiplexing is also described in detail, a technique used in many segment LCDs to allow them to be driven with less IO pins. Scoping out the LCD pins on a standard Casio F-91W wristwatch shows how the technique works, and it's easy to follow along seeing the signals displayed clearly on an oscilloscope. [Joey] also explains that generating all the signals needed is easy if you just go out and purchase a microcontroller with an integrated segment LCD controller, like the Microchip SAM L22.

As a primary example of what can be achieved when hacking segment LCDs, [Joey] shows how he repurposed the display from the Casio Databank DB-36. The LCD has 55 connections and tons of segments, and is hooked up with zebra strips - a rather delicate method of connecting a segment LCD. Using some sticky tape, he blocks out a pin going to the LCD, reassembles the watch, and looks for which segments don't work anymore. This technique allows the pinout of the display to be quickly mapped out.

Obviously, though, if you're reverse-engineering a display, you're limited to using the segments as laid out by the original designers. As [Joey] happily explains, though, you can actually get your own custom segment LCDs made without too much bother! He's already done it himself, creating a dupe to match the Casio F-91W in a Feather-compatible form factor to ease development of the Sensor Watch board. There is a quantity requirement, but you can end up spending less than $1 per unit on big orders.

While segment LCDs are old-school and basic, they're still a great technology for any low-power project that needs to display some data. After all, just think about how long the average digital wrist watch can last on a single coin-cell battery! [Joey]'s talk is a great primer if you're interested in taking advantage of these displays, whether in existing hardware or by getting your own made from scratch!

#cons #hackadaycolumns #2021hackadayremoticon #7segment #casio #casiof91w #casiowatch #lcd #remoticon #segmentlcd #sensorwatch

A One-Servo Mechanical Seven-Segment Display

The seven-segment display may be a bit prosaic after all these years, but that doesn't mean there aren't ways to spice it up. Coming up with a mechanical version of the typical photon-based display is a popular project, of which we've seen plenty of examples over the years. But this seven-segment display is quite a mechanical treat, and a unique way to flip through the digits.

With most mechanical displays, we're used to seeing the state of each segment changed with some kind of actuator, like a solenoid or servo. [Shinsaku Hiura] decided on a sleeker design using a 3D-printed barrel carrying one cam for each segment. Each hinged segment is attached to an arm that acts as a follower, riding on its cam and flipping on or off in a set pattern. Which digit is displayed depends on the position of the barrel, which is controlled with a single servo and a pair of gears. It trades mechanical complexity for electrical simplicity and overall elegance, and as you can see from the video below, it's pretty snappy.

We think the best part of this build is figuring out the shape of the cams. We wonder how they compare to the cam profiles in [Greg Zumwalt]'s mechanical display; it uses two separate discs with grooves, but the principle is pretty much the same.

Thanks to [Jan Derogee] for the tip.

#mischacks #7segment #cam #digit #display #follower #linkage #mechanical #servo #sevensegment