Haptic Smart Knob Does Several Jobs

March 13, 2022 by Ryan Flowers 63 Comments

A knob is a knob, a switch is a switch, and that’s that, right? And what about those knobs that have detents, set in stone at the time of manufacturing? Oh, and those knobs that let you jog left to right and then snap back to center — that can’t be modified…right? Well, you likely know where this is going, and in the video below the break, [scottbez1] shows off a new open source haptic input knob that can be all of these things with just some configuration changes!

The list of possibilities is long: virtual snap points, virtual spring loading, virtual detents, virtual end points. It’s a virtual smörgåsbord of configuration options that make this haptic smart knob a one stop shop for all of your knob needs. This is all possible because the knob contains a high resolution magnetic encoder chip that has a single degree resolution. The sensor is coupled, through software, to a brushless DC motor. The round LCD gives visual feedback as well.

As [Myself] on the Hackaday Discord channel noted, having configurable spacing and strength for detents, springs, and stops, is nothing short of incredible. Being able to reconfigure the knob at-will means that it can become context sensitive. It’s wonderfully unique and it’s open source, so you can make your own with the information available at GitHub.

And according to its creator, the only thing the Haptic Smart Knob can’t do is do your taxes or blend your margarita. Well, it’s open source, so perhaps some of our more enterprising readers can submit just the right pull request.

This isn’t Hackaday’s first Motorized Volume Knob feature, but it might be one of the neatest we have seen so far. Thanks to [mattvenn] on the Hackaday Discord server for the great tip!

Continue reading “Haptic Smart Knob Does Several Jobs” →

Vintage Multimeter Gets An LCD Transplant

March 8, 2022 by Lewin Day 10 Comments

Hackers are often of the sentimental type, falling in love with the look and feel of quality old hardware. Of course, sometimes that older hardware needs a little TLC to keep it running in the modern world. [Lex] had a beautiful vintage multimeter that sadly had a broken screen, and set about a nifty repair to restore it to working condition.

The HSN Avometer DA116 is a handsome thing, controlled with two dials and featuring a clean two-tone aesthetic. Even the font on the PCB’s silkscreen is gloriously pretty (can anyone ID that?). However, the original LCD was non-functional. A direct replacement part was sadly unavailable. Instead, to rectify this, [Lex] first hunted down another segmented LCD screen that had the same segment layout.

However, the new screen had a completely different pinout to the original part. Thus, after taking some notes and figuring out what all the pins did, [Lex] whipped up an adapter board to carry the new screen. With some protoboard, some pin headers, and a bunch of point-to-point wiring, the new screen worked just fine, and [Lex] had a functioning vintage meter once again!

The story actually came to us on Twitter, where we invited discussion about the best bodge wiring jobs out there. Feel free to contribute your own stories to the conversation! If you’re in the market for more LCD hacking, be sure to check out the excellent talk [Joey Castillo] gave at the 2021 Remoticon.

Remoticon 2021 // Joey Castillo Teaches Old LCDs New Tricks

February 24, 2022 by Lewin Day 6 Comments

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.” Continue reading “Remoticon 2021 // Joey Castillo Teaches Old LCDs New Tricks” →

The AUO-manufactured controller board of an LG-branded TV. (Credit: Andrew Menadue)

What To Do With A Broken Television When You Can’t Fix It

February 22, 2022 by Maya Posch 31 Comments

Who can say ‘no’ to a free TV, even if it’s broken? This was the situation [Andrew Menadue] ended up in last year when he was offered an LG 39LE4900 LCD TV. As [Andrew] describes in the blog post along with videos (see first part embedded after the break), this particular television had been taken to a television repair shop previously after the HDMI inputs stopped working, but due to a lack of replacement parts the owner had to make due with the analog inputs still working. That is, until those stopped working as well.

The nice thing about these TVs is that they are very modular inside, as [Andrew] also discovered to his delight. In addition to the LG controller board, an inverter board and the power supply board, this TV also contained a TCON PCB. After some initial unsuccessful swapping of the parts with EBay replacements, nothing was (surprisingly) working, but it did turn out that the TCON and inverter boards are made and sold by AUO (major Taiwanese display manufacturer), along with the display itself.

In the end it turned out that the AUO boards and screen were fine, and after sourcing a board to convert VGA input to the LVDS signal accepted by the TCON board, the whole display worked. Naturally using a board with HDMI inputs would be nice, but it does show how a ‘broken’ TV can be turned into a really nice, big monitor without all too much effort if it’s just the controller board that went on the fritz.

Continue reading “What To Do With A Broken Television When You Can’t Fix It” →

Reverse Engineering: Trash Printer Gives Up Its Control Panel Secrets

January 25, 2022 by Dave Rowntree 7 Comments

Many of us hardware-oriented types find it hard to walk past a lonely-looking discarded item of consumer electronics without thinking “If only I could lug that back to the car and take it home to play with” and [phooky] from NYC Resistor is no stranger to this sentiment. An old Epson WF-2540 inkjet printer was disassembled for its important ‘nutrients,’ you know, the good stuff like funky motors, encoders and switches. But what do you do with the control panel? After all, they’re usually very specific to the needs of the device they control, and don’t usually offer up much scope for reuse.

The RP2040 PIO is quite capable of pushing out those LCD pixels

[phooky] doesn’t usually bother with them, but this time decided to have a crack at it for fun. Inside, nothing out of the ordinary, with a large single-sided PCB for the key switches and LEDs, and a small PCB hosting the LCD display. The easy part was to figure out how the keyboard scanning was done, which turned out to be pretty simple, it just uses some 74-series shift register devices to scan the columns and clock out the row lines. A Raspberry Pi Pico module was pressed into service to scan the keyboard and enable a keyboard map to be created, by pure brute-force. No need to trace the circuit.

Things got interesting when [phooky] started looking into the LCD interface, based on the Epson E02A46EA chip (good luck finding a datasheet for that one!) and quickly realised that documentation simply wasn’t available, and it would be necessary to do things the hard way. Poking around the lines from the main CPU (an Epson E01A9CA , whatever that is) the display clock was identified, as well as some control signals, and three lines for the RGB channels. By throwing a Saleae data capture into some ROM exploring software, the display configuration was determined to be a standard 320×120 unit.

The PIO unit of the RP2040 was used to generate the video waveforms and push the pixels out to the LCD controller, allowing the RP2040 board to be wired inside the case permanently, converting the control panel into a USB device ready for action!

Want to know a little more about reverse engineering junk (or not) items and repurposing them to your will? Checkout this hacking piece from a couple of weeks back. For something a little more advanced, you could try your hand at a spot of car ECU hacking.

Thanks [Perry] for the tip!

Tiny Switch Ornament Plays GIFs With An ESP32

December 19, 2021 by Dave Rowntree 4 Comments

It constantly amazes us what we hackers can build these days, (electronics shortages aside) we have access to an incredible array of parts, with specifications that only a few years ago would be bank-breaking and longer ago just fantasy. It’s nice to see people building one-offs just for fun, in spite of the current difficulties getting parts to actually be delivered. For example, check out this miniaturized Nintendo Switch created by [scottbez1] that plays animated GIFs from an SD card on tiny 1.14″ LCD display.

Obviously such a diminutive hack requires a custom PCB, which was a job for KiCAD. Armed with a 3D model of the LCD, the casing and PCB outline were drawn using Fusion 360. The PCB hosts a LilyGo ESP32 module for all the heavy lifting, with the WiFi adding some fun future capabilities not yet explored. The design is about as tight as it can get without pushing the limits of the PCB process too far, including a neat trick of sneaking passives inside the body of the SD card! That’s another space-saving idea we’ll be banking.

All-in-all a neat little hack, showing some good modelling and construction techniques and a good looking end result. Code for your reference may be found on the project GitHub, but as of writing the hardware design is not available.

Whilst this project shrinks the Switch, here’s one that goes the other way and super-sizes it, and if you have a switch lite but crave a little modern charging magic, then look no further than this Qi wireless charging hack.

Continue reading “Tiny Switch Ornament Plays GIFs With An ESP32” →

Slick Keyboard Built With PCB Magic

November 21, 2021 by Dave Rowntree 21 Comments

Sometimes a chance conversation leads you to discover something cool you’ve not seen before, and before you know it, you’re ordering parts for yet another hardware build. That’s what happened to this scribe the other day when chatting on some random discord, to QMK maintainer [Nick Brassel aka tzarc] about Djinn, a gorgeous 64-key split mechanical keyboard testbed. It’s a testbed because it uses the newest STM32G4x microcontroller family, and QMK currently does not have support for this in the mainline release. For the time being, [Nick] maintains a custom release, until it gets merged.

Hardware-wise, the design is fabulous, with a lot of attention to detail. We have individual per-key RGB LEDs, RGB underglow, a rotary encoder, a five-way tactile thumb switch, and a 240×320 LCD per half. The keyboard is based on a three PCB stack, two of which are there purely for structure. This slick design has enough features to keep a fair few of us happy.

Interestingly, when you look at the design files (KiCAD, naturally) [Nick] has chosen to take a mirrored approach to the PCB. That means the left and right sides are actually the same PCB layout. The components are populated on different sides of the PCB depending on which half you’re looking at! By mirroring footprints on both PCB sides, and hooking everything up in parallel, it’s possible to do it all with a single master layout.

This is a simple but genius idea that this scribe hadn’t come across before (the shame!) Secondarily it keeps costs down, as your typical Chinese prototyping house will not deal in PCB quantities below five, so you can make two complete keyboards on one order, rather than needing two orders to make five. (Yes, there are actually three unique PCBs, but we’re simplifying the situation, ok?)

Now, if only this pesky electronics shortage could abate a bit, and we could get the parts to build this beauty!

Obviously, we’ve covered many, many keyboards over the years. Here’s our own [Kristina’s] column all about the things. If you need a little help with your typing skills, this shocking example may be the one for you. If your taste is proper old-school clackers, there’s something for everyone.