E-ink Typewriter Is Refreshingly Slow

It’s pretty hard to use the internet to complete a task without being frequently distracted. For better or worse, there are rabbit holes at every turn and whilst exploring them can be a delight, sometimes you just need to focus on a task at hand. The solution could be in the form of distraction-blocking software, razor-sharp willpower, or a beautifully crafted modern “typewriter”. The constraint and restriction of a traditional typewriter appealed to [NinjaTrappeur], but the inability to correct typos and share content online was a dealbreaker. A hybrid was the answer, with a mechanical keyboard commanding an E-ink display driven by a Raspberry Pi.

The main point of interest in this build is the E-ink screen. Though it’s easy to acquire theses displays in small sizes, obtaining a screen greater than four inches proved to be a challenge. Once acquired, driving the screen over SPI was easy, but the refresh rate was horrific. The display takes three seconds to redraw, and whilst [NinjaTrappeur] was hoping to implement a faster “partial refresh”, he was unable to read the appropriate values from the onboard flash to enable manual control of the drawing stages. Needless to say, [NinjaTrappeur] asks if people have had success driving these displays at a more usable rate, and would love to hear from you if so.

Some auxiliary hacks come in the form of terminal emulator adaptation, porting the E-ink screen library from C++ to C, and capturing the keyboard input. A handmade wooden case finishes it off.

If it’s old-school typewriters that float your boat, we’ve got you covered: this solenoid-actuated typewriter printer eventually became a musical instrument, and this daisy wheel machine produces ASCII art from a live camera.

[Via Boing Boing]

R3-14, The Personal Assistant Two Years In The Making

One of the great things about hacking together projects these days is how many powerful subsystems are readily available to reuse. [Sanjeet] took full advantage of a whole slate of reusable pieces when he built R3-14 — a personal assistant robot that you can see in action in the video below.

Many people started out in electronics building something simple like a crystal radio or an LED cube. But how far could you get if your projects had to begin at the most basic level, by drawing out copper wire, fabricating coils, capacitors, semiconductor devices, and batteries? Even if you know how to do all those things, it would take a lot of time, so there is no shame in using off-the-shelf components. By the same token, [Sanjeet] uses Google Assistant, 433 MHz RF transmitters, and a Raspberry Pi as components in this build. Along the way, he also contributed some reusable pieces himself, including an LED library for the PI and a library to allow Siri to control a Raspberry Pi.

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Contest Results: Raspberry Pis Put On A Show

Some of the most satisfying projects of all are the ones that do something visual. All the network routers, data loggers, and thermostats are great. But we are visual creatures and even a humble blinking LED is enough to give you a little rush even compared to finding a large prime number. We wanted to see what our community could do visually with a Raspberry Pi so we challenged you with the Visualize it with Pi contest.

As always, the competition was brisk, with a lot of great projects. This contest showed off the trend towards using LED modules and assemblies to add visuals to projects. Why not? They are cheap enough and a well-integrated module can make a project simple to wire and integrate.

We didn’t see as many media-related projects as you might expect, although there was one tied into Stranger Things, one to Tron, and the virtual reality lighting project did have some Star Wars images. Projects ranged from the practical storage box labels to the whimsical lemonade bottle that strobes to the beat of the music. If none of that is hardcore enough for you, there was even a Raspberry Pi-controlled radio telescope. You can find all the entries over on Hackaday.io. Now let’s see which entries managed to turn the head of the judging panel.

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Dirty Video Mixing With The Raspberry Pi Zero

Don’t get too excited now, we aren’t talking about that kind of dirty video. There’s plenty of other places on the Internet you can go to find that sort of thing. No, this video mixer is “dirty” because it combines two composite video streams into one garbled up mess that’s best viewed on an old CRT TV. Why, you may ask? Because rock and roll, that’s why.

Created by [Luke Blackford] as a visual for his band’s performances, the “Dirty Pi” is an exceptionally simple way to create some wild imagery with two Raspberry Pi Zeros. It might not be the most practical of devices, but if you want so throw some creepy looking video up on screens all over the house (say for an upcoming Halloween party), this is a fantastic way to do it on the cheap.

The idea is simple: connect the oft-forgotten composite video outputs of two Pi Zeros to a potentiometer, which then leads to the display. Play different videos on the Pis with the media player of your choice, and twiddle the potentiometer to create ghosting and interference. If you want to get that true 1980’s retro feel, put the whole thing into an old VHS cassette like [Luke] did, and you’re ready to rock.

Those who’ve been around the block a few times might recognize this trick as a variation of the [Karl Klomp] Dirty Video Mixer, and [Luke] tells us he likes this project because he was able to pull it off without writing any code or even doing any complex wiring, though he does imagine a future version where he adds some remote control functionality.

If you like your video mixers with more smarts and less dirt, we’ve covered a very slick build using the LM1881 in the past.

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Another Drawbot Uses A Pi And Web Sockets

There’s something about art. Cavemen drew on walls. People keep programming drawing robots. One we’ve seen recently is [Andy’s] Drawbot that uses WiFi and WebSockets to draw on just about any flat surface. What’s more, the Johnson County Library has a great write-up about how they built one and if you want a go at it, you’ll find their instructions very helpful. The video below is pretty inspirational, too.

What makes this build especially interesting is that it uses a drive system with two fixed points attached with suction cups.  There are a variety of 3D printed parts — some just for the build and some are older parts repurposed.

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Hack My House: Running Raspberry Pi Without An SD Card

Many of us have experienced the pain that is a Raspberry Pi with a corrupted SD card. I suspect the erase-on-write nature of flash memory is responsible for much of the problem. Regardless of the cause, one solution is to use PXE booting with the Raspberry Pi 3. That’s a fancy way to say we’ll be booting the Raspberry Pi over the network, instead of from an SD card.

What does this have to do with Hacking My House? As I discussed last time, I’m using Raspberry Pi as Infrastructure by building them into the walls of every room in my house. You don’t want to drag out a ladder and screwdriver to swap out a misbehaving SD card, so booting over the network is a really good solution. I know I promised we’d discuss cabling and cameras. Think of this as a parenthetical article — we’ll talk about Ethernet and ZoneMinder next time.

So let’s dive in and see what the Preboot Execution Environment (PXE) is all about and how to use PXE with Raspberry Pi.

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Perhaps The Ultimate Raspberry Pi Case: Your PC

One of the great joys of owning a 3D printer is being able to print custom cases for boards like the Raspberry Pi. What’s more, if you are using a desktop PC, you probably don’t have as many PCI cards in it as you used to. Everything’s moved to the motherboard. [Sneekystick] was using a Pi with a PC and decided the PC itself would make a great Pi case. He designed a bracket and it looks handy.

The bracket just holds the board in place. It doesn’t connect to the PC. The audio, HDMI, and power jacks face out for access. It would be tempting and possible to power the board from the PC supply, but to do that you have to be careful. Connecting the GPIO pins to 5V will work, but bypasses the input protection circuitry. We’ve read that you can find solder points near the USB plug and connect there, but if you do, you should block out the USB port. It might be nice to fill in that hole in the bracket if you planned to do that.

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