We’ve seen a wide variety of hacks that keep time, but [ch00f]’s latest build takes a new spin on counting the seconds. The Gutenberg Clock keeps time by reading books on a scrolling LED screen.
The content for the clock is sourced from the Project Gutenberg, which releases books with expired copyright for free. The library on the clock consists of around twenty thousand such books. Read at eighty words per minute, the clock won’t repeat a passage for the next thirty-three years.
While the clock doesn’t display time itself, it is synchronized to time. Two identical clocks should display the same text at the same time. To get the time, [ch00f] first tried hacking apart a cheap radio clock, which is synchronized to NIST’s 60 kHz broadcast. After reverse engineering the protocol with great success, stray RF energy from the display turned out to cause too much interference.
With the cheap solution out the window, [ch00f] built a custom breakout for an Adafruit GPS module and used it to get the time. This was his first RF board, but it worked out fine.
Books are loaded onto a FAT filesystem on an SD card, and [ChaN]’s FatFS is used to interpret the filesystem. A microcontroller then sends the text out at a constant rate to a serial port on the display which he hacked his way into.
The project is a neat mix of art and electronics. Stick around for a video overview after the break.
Continue reading “Gutenberg Clock Keeps Time by Reading Books”
[Matthew’s] recent blog post does a good job explaining the basics of the Raspberry Pi’s file system. The Linux operating system installed on a Pi is generally installed on two different partitions on an SD card. The first partition is a small FAT partition. All of the files on this partition are used for the initial booting of the Pi. This partition also includes the kernel images. The second partition is the root file system and is generally formatted as ext4. This partition contains the rest of the operating system, user files, installed programs, etc.
With that in mind you can deduce that in order to backup your Pi, all you really need to do is backup all of these files. [Matt] has written some scripts to make this a piece of cake (or pie). The first script will simply copy all of the files into a gzipped archive. You can save this to an external SD card, USB drive, or network share.
The second script is perhaps more interesting. This script requires that you have one free USB port and a USB SD card reader. The script will automatically format the extra SD card to contain the two critical partitions. It will then copy the “boot” files to the new boot partition and the root file system files to the new SD card’s root partition. When all is said and done, you will end up with an SD card that is an exact copy of your current running file system.
This can be very handy if you have multiple Pi’s that you want to run the same software, such as in a Pi cluster. Another good example is if you have spent a lot of time tweaking your Pi installation and you want to make a copy for a friend. Of course there are many ways to skin this cat, but it’s always fun to see something custom-built by a creative hacker.
Here’s a hack with more of a survivalist flair to it. [Ligament] and some friends used the fat from butchering a deer to make soap, candles, and toiletries.
It’s hunting season and [Ligament’s] dad is processing the deer which he harvested. Wild game doesn’t have the amount of fat you’d find on a domesticated animal, but there is still a fair amount. The group cut off as much as they could before cutting up the rest of the meat. The trimmings are put in a pot with water and boiled until the fat starts to rise. It is ladled off and strained through some cheese cloth. The fat hardens overnight and can be picked up out of the container as a big disk. It is reheated and strained through a mesh coffee filter to achieve the final product. From there the fat was used as an ingredient in the recipes for candles, soap, and things like lip balm. For details on that heck out the comments for each image in the gallery linked above.
It’s a good thing to waste as little as possible. But this skill will be indispensable once the Zombie Apocalypse comes. You might also want to know how to chlorinate your own water.
[Victor’s] girlfriend works at a museum and enlisted his expertise in designing an interactive detective game for kids visiting the museum. The vision was for the kids to discover phone numbers that they could call for clues. Originally he planned to display the clues on a character LCD, but obviously it’s much neater to hear the clues in the handset of the phone.
Quickly switching gears, [Victor] dropped the ATtiny2313 and started over with an Xmega chip — in fact, it was our recent Xmega post that inspired him to document his project. The microcontroller is responsible for a lot of goings-on. It scans the key matrix for inputs, simulates the DTMF touch tones, reads audio files from a FAT file system on an SD card, and plays them back over the hand set’s speaker. Since most of the hardware is already built into the phones, it was not hard to fit his add-ons inside the case. A simple audio amplifier circuit joins the microcontroller, which is patched into the rows and columns of the keyboard. Take a gander at the video after the break to see the device in action.
Continue reading “Ever wonder where cool interactive museum exhibits come from?”
[Rahul Sapre] sent us a guide to porting EFSL to any microcontroller (PDF). The Embedded Filesystems Library adds FAT support to C compiled microcontrollers. It is targeted at the AVR line of chips but can be adapted to any architecture that works with a C compiler. [Rahul’s] guide will take you through the process of adapting the latest stable 0.2.8 version to new hardware by using a PIC uC as the working example. The non-stable development branch of EFSL is working toward multiple-platform support so consider lending a hand if this interests you.
Here’s a quick demo that FAT’s [Theo Watson] put together. It uses the iPod’s accelerometer to measure how fast it’s spinning and plays the sound file accordingly. This only works on the iPod touch 2nd gen because of its curved case. He says scratching is coming next, but currently the app doesn’t know which direction it’s spinning since it’s measuring outward force. This project was done in response to [vanderlin]’s AR scratching that used fiducials on records.
A coworker approached us today with a corrupted SD card. It was out of her digital camera, and when plugged in, it wasn’t recognized. This looked like the perfect opportunity to try out [Christophe Grenier]’s PhotoRec. PhotoRec is designed to recover lost files from many different types of storage media. We used it from the command line on OSX, but it works on many different platforms.
It’s a fairly simple program to use. We plugged in the card and launched PhotoRec. We were prompted to select which volume we wanted to recover. We selected “Intel” as the partition table. PhotoRec didn’t find any partitions, so we opted to search the “Whole disk”. We kept the default filetypes. It then asked for filesystem type where we chose “Other” because flash is formatted FAT by default. We then chose a directory for the recovered files and started the process. PhotoRec scans the entire disk looking for known file headers. It uses these to find the lost image data. The 1GB card took approximately 15 minutes to scan and recovered all photos. This is really a great piece of free software, but hopefully you’ll never have to use it.