The clock demo on display

Drive 1024×600 Pixels Via I2C With An ATtiny85

If you need to drive a big screen for a project, it’s fair to say your first thought isn’t going to be to use the ATtiny85. With just 512 bytes of RAM and 8 kilobytes of flash memory, the 8-bit micro seems a little cramped to drive, say, a 10″ screen. Yet that’s exactly what [ToSStudio] is doing with TinyTFT_LT7683: 1024 x 600 pixels of TFT goodness, over I2C no less.

With the right TFT controller, this little micro-controller can do magic.

The name kind of gives away the secret: it won’t work on just any TFT display. It’s using properties of the LT7683 display driver, though if you don’t have one of those, the RA8875 is also compatible. Those drivers can take more than just a pixel stream– a good thing, since you’d be hard pressed to get that many pixels streaming from an ATtiny. These are character/graphic display drivers, which means you can get them to draw both characters and graphics on the screen if you speak the lingo.

It’s still not blazing fast; the documentation suggests “static or moderately dynamic UIs” as the suggested use case, and a clock is of the pre-programmed examples. From that, we can surmise that you can get 1 FPS or better with this code. You’re limited both by the simple micro-controller and the bandwidth of the I2C bus, but within those limits this seems like a very powerful technique.

This isn’t the first ATtiny graphics library to blow our minds, but if you really want an impressive graphics demo from the little micro that could, you really need to race the beam.

Thanks to [Thomas Scherer] for the tip!

Review: Cherry G84-4100 Keyboard

The choice of a good keyboard is something which consumes a lot of time for many Hackaday readers, judging by the number of custom input device projects which make it to these pages. I live by my keyboard as a writer, but I have to admit that I’ve never joined in on the special keyboard front; for me it’s been a peripheral rather than an obsession. But I’m hard on keyboards, I type enough that I wear them out. For the last five years my Hackaday articles have come via a USB Thinkpad keyboard complete with the little red stick pointing device, but its keys have started parting company with their switches so it’s time for a replacement.

I Don’t Want The Blackpool Illuminations

A picture of the Blackpool illuminations at night against a dark sky.
Is it a gamer’s keyboard, or the Blackpool seafront at night? I can’t tell any more. Mark S Jobling, Public domain.

For a non keyboard savant peering over the edge, this can be a confusing choice. There’s much obsessing about different types of mechanical switch, and for some reason I can’t quite fathom, an unreasonable number of LEDs.

I don’t want my keyboard to look like the Blackpool Illuminations (translation for Americans: Las Vegas strip), I just want to type on the damn thing. More to the point, many of these “special” keyboards carry prices out of proportion to their utility, and it’s hard to escape the feeling that like the thousand quid stereo the spotty kid puts in his Opel Corsa, you’re being asked to pay just for bragging rights.

Narrowing down my needs then, I don’t need any gimmicks, I just need a small footprint keyboard that’s mechanically robust enough to survive years of my bashing out Hackaday articles on it. I’m prepared to pay good money for that.

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Cheap 10x10cm Hotplate Punches Above Its Weight

For less than $30 USD, you can get a 10×10 centimeter hotplate with 350 Watts of power. Sounds mighty fine to us, so surely there must be a catch? Maybe not, as [Stefan Nikolaj]’s review of this AliExpress hotplate details, it seems to be just fine enough.

At this price, you’d expect some shoddy electronics inside, or maybe outright fiery design decisions, in the vein of other reviews for similar cheap heat-producing tech that we’ve seen over the years. Nope – the control circuitry seems to be more than well-built for our standards, with isolation and separation where it matters, the input being fused away, and the chassis firmly earthed. [Stefan] highlights just two possible problem areas: a wire nut that could potentially be dodgy, and lack of a thermal fuse. Both can be remedied easily enough after you get one of these, and for the price, it’s a no-brainer. Apart from the review, there’s also general usage recommendations from [Stefan] in the end of the blog post.

While we’re happy to see folks designing their own PCB hotplates or modifying old waffle irons, the availability of cheap turn-key options like this means there’s less of a reason to go the DIY route. Now, if you’re in the market for even more build volume, you can get one of the classic reflow ovens, and maybe do a controller upgrade while you’re at it.

Warnings About Retrobright Damaging Plastics After 10 Year Test

Within the retro computing community there exists a lot of controversy about so-called ‘retrobrighting’, which involves methods that seeks to reverse the yellowing that many plastics suffer over time. While some are all in on this practice that restores yellow plastics to their previous white luster, others actively warn against it after bad experiences, such as [Tech Tangents] in a recent video.

Uneven yellowing on North American SNES console. (Credit: Vintage Computing)
Uneven yellowing on North American SNES console. (Credit: Vintage Computing)

After a decade of trying out various retrobrighting methods, he found for example that a Sega Dreamcast shell which he treated with hydrogen peroxide ten years ago actually yellowed faster than the untreated plastic right beside it. Similarly, the use of ozone as another way to achieve the oxidation of the brominated flame retardants that are said to underlie the yellowing was also attempted, with highly dubious results.

While streaking after retrobrighting with hydrogen peroxide can be attributed to an uneven application of the compound, there are many reports of the treatment damaging the plastics and making it brittle. Considering the uneven yellowing of e.g. Super Nintendo consoles, the cause of the yellowing is also not just photo-oxidation caused by UV exposure, but seems to be related to heat exposure and the exact amount of flame retardants mixed in with the plastic, as well as potentially general degradation of the plastic’s polymers.

Pending more research on the topic, the use of retrobrighting should perhaps not be banished completely. But considering the damage that we may be doing to potentially historical artifacts, it would behoove us to at least take a step or two back and consider the urgency of retrobrighting today instead of in the future with a better understanding of the implications.

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The New Pebble: Now 100% Open Source

The Pebble was the smartwatch darling of the early 2010s, a glimpse of the future in the form of a microcontroller and screen strapped to your wrist. It was snapped up by Fitbit and canned, which might have been the end of it all were it not for the dedication of the Pebble community.

Google open-sourced the OS back in January this year, and since then a new set of Pebble products have appeared under the guidance of Pebble creator [Eric Migicovsky]. Now he’s announced the full open-sourcing of the current Pebble hardware and software stack. As he puts it, “Yesterday, Pebble watch software was ~95% open source. Today, it’s 100% open source”.

If you’re curious it can all be found in repositories under the Core Devices GitHub account. Building your own Pebble clone sounds cool, but perhaps the real value lies instead in giving the new Pebbles something the original never had, an assured future. If you buy one of the new watches then you’ll know that it will remain fixable, and since you have the full set of files you can create new parts for it, or update its software. We think that’s the right way to keep a personal electronic device relevant.

If you want a new Pebble they have a store, meanwhile read some of our previous coverage of its launch.

Nest Thermostat: Now 100% Less Evil

If you have a Nest thermostat of the first or second generation, you probably noticed it recently became dumber. Google decided to pull the plug on the servers that operate these devices, turning them into — well — ordinary thermostats. Lucky for us [codykociemba] has been keeping up with various exploits for hacking the thermostat, and he started the NoLongerEvil-Thermostat project.

If you want to smarten up your thermostat again, you’ll need a Linux computer or, with some extra work, a Mac. The thermostat has a DFU-enabled OMAP loader. To access it, you have to plug it into USB and then reboot it. There is a narrow window for the loader to grab it, so you have to be running the software before you reboot or you’ll miss it.

You can control your thermostat again!

After that, the flash is relatively fast, but the Nest will look dead for a brief time. Then the No Longer Evil logo will show, and you are in business. We wish the hack simply replaced the Google software with a local website, but it doesn’t. It redirects all the network traffic to a custom URL. Then you can control your thermostat from the nolongerevil.com website. So we don’t know what will happen if they decide to stop hosting the remote server that powers this. You can also run the code locally if you’ve got a server up.

If you get another year out of your trusty thermostat, that’s a year you wouldn’t have had otherwise. We do worry a bit about putting an odd device on your network. In theory, the project is open source, but all the important bits are in a binary U-Boot image file, so it would take some work to validate it. To get you started, the command to dump the content is probably: dumpimage -T kernel -p 0 -o kernel uImage. Or, you could watch it with Wireshark for a bit.

We were happy to get some more use out of our Nest.

Speech Synthesis On A 10 Cent Microcontroller

Speech synthesis has been around since roughly the middle of the 20th century. Once upon a time, it took remarkably advanced hardware just to even choke out a few words. But as [atomic14] shows with this project, these days it only takes some open source software and 10-cent microcontroller

The speech synth is implemented on a CH32V003 microcontroller, known for its remarkably low unit cost when ordered in quantity. It’s a speedy little RISC-V chip running at 48 MHz, albeit with the limitation of just 16 KB of Flash and 2 KB of SRAM on board.

The microcontroller is hooked up to a speaker via a simple single-transistor circuit, which allows for audio output. [atomic14] first demonstrates this by having the chip play back six seconds of low quality audio with some nifty space-saving techniques to squeeze it into the limited flash available. Then, [atomic14] shows how he implemented the Talkie library on the chip, which is a softwarehttps://www.youtube.com/watch?v=RZvX95aXSdM implementation of Texas Instruments’ LPC speech synthesis architecture—which you probably know from the famous Speak & Spell toys. It’s got a ton of built in vocabulary out of the box, and you can even encode your own words with some freely available tools.

We’ve seen [atomic14] tinker with these chips before, too.

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