Graphing Calculator Dual Boots With Pi Zero

March 4, 2018 by Tom Nardi 41 Comments

The nearly limitless array of consumer gadgets hackers have shoved the Raspberry Pi into should really come as no surprise. The Pi is cheap, well documented, and in the case of the Pi Zero, incredibly compact. It’s like the thing is begging to get grafted into toys, game systems, or anything else that could use a penguin-flavored infusion.

But this particular project takes it to the next level. Rather than just cramming the Pi and a cheap LCD into his Numworks graphing calculator, [Zardam] integrated it into the device so well that you’d swear it was a feature from the factory. By exploiting the fact that the calculator has some convenient solder pads connected to its SPI bus, he was able to create an application which switches the display between the Pi and the calculator at will. With just a press of a button, he’s able to switch between using the stock calculator software and having full access to the internal Pi Zero.

In a very detailed write-up on his site, [Zardam] explains the process of getting the Pi Zero to output video over SPI. The first part of the battle was re-configuring the GPIO pins and DMA controller. After that, there was the small issue of writing a Linux SPI framebuffer driver. Luckily he was able to find some work done previously by [Sprite_TM] which helped him get on the right track. His final driver is able to push 320×240 video at 50 FPS via GPIO, more than enough to kick back with some DOOM.

With video sorted out, he still needed a way to interface the calculator’s keyboard with the Pi. For this, he added a function in his calculator application that echoed the keys pressed to the calculator’s UART port. This is connected to the Pi, where a daemon is listening for key presses. The daemon then generates the appropriate keycodes for the kernel via uinput. [Zardam] acknowledges this part of the system could do with some refinement, but judging by the video after the break, it works well enough for a first version.

We’ve seen the Pi Zero get transplanted into everything from a 56K modem to the venerated Game Boy, and figured nothing would surprise us at this point. But we’ve got to say, this is one of the cleanest and most practical builds we’ve seen yet.

[Thanks to EdS for the tip]

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K40 Laser Cutter, Meet Raspberry Pi

March 4, 2018 by Jenny List 24 Comments

The inexpensive Chinese K40 laser cutter has become the staple of many a small workshop within our community, providing a not-very-large and not-very-powerful cutter for a not-very-high price. As shipped it’s a machine that’s not without its flaws, and there is a whole community of people who have contributed fixes and upgrades to make these cutters into something a lot more useful.

[Alex Eames] bought a K40, and since he’s the person behind the Raspi.tv Raspberry Pi business, when he switched from the supplied Corel-based software to the popular open-source K40 Whisperer his obvious choice was to run it on a Raspberry Pi. Since K40 Whisperer is written in Python he reasoned that the Pi’s ARM platform would not prevent its use, so he set to work and documented the process and his workflow.

It’s a straightforward enough process, and his K40 now has a Pi into which he can SFTP his files rather than the inevitable old laptop that accompanies most K40s. With so many K40 improvements created by its community, we find it surprising that some enterprising Chinese manufacturer hasn’t seen the opportunity to make a quick buck or two extra and incorporate some of them into their products at the factory, including one of the many single board computers that could perform this task.

We’ve covered a lot of K40 stories over the years, if you are new to this machine you might like to take a look at this story of bringing one to life.

DIY Text-to-Speech With Raspberry Pi

March 2, 2018 by Kristina Panos 10 Comments

We can almost count on our eyesight to fail with age, maybe even past the point of correction. It’s a pretty big flaw if you ask us. So, how can a person with aging eyes hope to continue reading the printed word?

There are plenty of commercial document readers available that convert text to speech, but they’re expensive. Most require a smart phone and/or an internet connection. That might not be as big of an issue for future generations of failing eyes, but we’re not there yet. In the meantime, we have small, cheap computers and plenty of open source software to turn them into document readers.

[rgrokett] built a RaspPi text reader to help an aging parent maintain their independence. In the process, he made a good soup-to-nuts guide to building one. It couldn’t be easier to use—just place the document under the camera and push the button. A Python script makes the Pi take a picture of the text. Then it uses Tesseract OCR to convert the image to plain text, and runs the text through a speech synthesis engine which reads it aloud. The reader is on as long as it’s plugged in, so it’s ready to work at the push of a button. We can probably all appreciate such a low-hassle design. Be sure to check out the demo after the break.

If you wanted to use this to read books, you’d still have to turn the pages yourself. Here’s a BrickPi reader that solves that one.

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Who Ate All The Pi?

March 1, 2018 by Jenny List 44 Comments

Wednesday was the last day of February, and leap year questions aside that date marks the anniversary of the Raspberry Pi launch. The oldest commercially available Pi is now 6 years old, and to mark the occasion the Raspberry Pi people have put up a retrospective of all their different models.

There is a primordial prototype from [Eben Upton]’s bench that involves an Atmel processor, but the first board dangled in front of the public was a Broadcom one, the BCM2763 ‘micro DB’. This was a form factor like one of those Android TV sticks, and while it was not a Raspberry Pi internal design or indeed sporting the SoC to be used by the Pi itself, it was sufficient to capture the imagination of what would become the Raspberry Pi community.

If you got out of bed early (British time) on the 29th of February 2012 and tried to order one of the first commercially available boards, you were most likely to be out of luck. The relatively small first batch from China was oversubscribed massively, both the RS and Farnell websites went down completely for most of the day. We received our model at some point in May. It’s an over-used phrase, “And the rest is history”, but it seems entirely appropriate here. The Pi has passed through several iterations and increased in both computing power and memory, it has spawned a whole industry of peripherals, a huge community, and a host of competitors. We have quite a few of the boards in the blog post, but some of the more exotic ones have evaded us.

It’s not the best or most powerful board out there, many of its competitors can beat it on performance, but it remains the one to beat in small and cheap Linux-capable single board computers. Why is this the case? It has probably the best-supported Linux distro of all of them, and that community has already answered many of the queries you might find with your board.

So there’s the story, a successful product line, community, and foundation. The Pi blog piece is very much their PR, but it doesn’t need to gild the lily. However, that will not stop competitors from taking aim at its crown, and the field remains open for one of them to topple it. Which of course makes for fascinating stories for us here at Hackaday, so we’d encourage anybody with an electronics factory in China, a bright team, and some good ideas to give it a try. Meanwhile, we’ll be looking towards Cambridge for whatever new products will sport the fruity logo.

PipeCam: Shallow-Water Exploration With Raspberry Pi

February 27, 2018 by Kristina Panos 14 Comments

In what began as a personal challenge he issued to himself, [Fred] is in the process of building an underwater camera that’s capable of long-term photography in shallow waters. He’d like it to last about five hours on a charge while taking a photo every five minutes. Ideally, it will be as cheap as possible and constructed from readily available parts. Solving the cheap/available equation would theoretically make the camera easily to replicate, which is the third major requirement.

[Fred] has recently made great strides, both in the circuitry and the capsule design. The latest version uses a Raspberry Pi 3 with a V2 camera module and runs on a 12 V, 2.4 Ah rechargeable lead-acid battery. Everything is mounted on a piece of hardboard that slides into a 110mm piece of PVC. At one end, the camera looks out through a 10mm acrylic lens fixed into a heavy-duty PVC fitting, and a DS1307 RTC provides a handy clock for shooting time lapses. With a friend’s help, he pressure-tested the housing and found that it can withstand 4 bar without leaking. He is still doing dry tests and trying hard to resist the urge to throw it in the water.

PipeCam is a work in progress, and [Fred] has many ideas for improvements. He’d like to add an Arduino to govern the battery use and provide its vital signs back to the Pi, and add an LDR to decide whether there’s enough light to warrant turning the Pi on to take pictures.

PVC is great for custom capsule building. But if you want to get started with underwater photography a little faster and want to build something instead of just buying a GoPro, try sealing your camera in something that’s already watertight.

Old Modem, New Internet.

February 26, 2018 by James Hobson 37 Comments

Do you remember the screeching of a dial-up modem as it connected to the internet? Do you miss it? Probably not, but [Erick Truter] — inspired by a forum post and a few suggestions later — turned a classic modem into a 3G Wi-Fi hotspot with the ubiquitous Raspberry Pi Zero.

Sourcing an old USRobotics USB modem — allegedly in ‘working’ condition — he proceeded to strip the modem board of many of its components to make room for the new electronic guts. [Truter] found that for him the Raspberry Pi Zero W struggled to maintain a reliable network, and so went with a standard Pi Zero and a USB Wi-Fi dongle dongle. He also dismantled a USB hub to compensate for the Zero’s single port. Now, to rebuild the modem — better, faster, and for the 21st century.

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Crankshaft: Open Source Car Computer

February 26, 2018 by Al Williams 46 Comments

Modern cars and head units are pretty fancy gadget-wise. But what if your car still has an 8-track? No problem. Just pick up a Raspberry Pi 3 and a seven-inch touchscreen, and use Crankshaft to turn it into an Android Auto setup.

The open source project is based on OpenAuto which, in turn, leverages aasdk. The advantage to Crankshaft is it is a plug-and-play distribution. However, if you prefer, you can build it all yourself from GitHub.

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