Printing Printed Circuit Boards

November 12, 2013 by 65 Comments

circuit

We really respect the old timers out there and their amazing ways of crafting PCBs; they used black tape on clear acetate sheets to create single layers of PCBs with a photoetching process. Now creating a PCB is a simple matter of opening up a CAD package, but like the old timers we’re still dealing with nasty chemicals or long shipping times from China.

The EX¹, a new robot on Kickstarter – hopes to change that. They’ve created a PCB fabrication process that’s as simple as printing something with an inkjet printer. Just put in a piece of substrate – anything from Kapton to acrylic to fabric – and in a few minutes you have a single-sided PCB in your hands.

The printer dispenses two chemicals, silver nitrate and ascorbic acid, that react and produce traces and pads for the circuit. Right now, the EX¹ is limited to single-side boards, but experiments on creating multi layer boards are ongoing.

In any event, we’re really impressed with how simple the EX¹ setup actually is. Inkjet is a mature, well understood technology with more than enough resolution for simple homebrew circuits, and the AgNO3 + Vitamin C formula could easily be adapted to an inkjet printer modification.

Building A Better Serial Camera

November 12, 2013 by 22 Comments

If your next project does anything with cameras or machine vision, you’ll probably be looking at something like a USB webcam attached to an ARM board or a netbook. Sometimes, though, that setup blows will blow your budget – power or otherwise – out of the water. For small projects, you’re limited to small, serial-accessible cameras, and in that domain you really don’t have a lot of choices.

[Ibrahim] realized the cheapest serial cameras are about $35, and with basic image processing that cost skyrockets up to about $100. He set out to build his own alternative, and ended up with an awesome serial camera module that should only cost about $15 in quantity.

The module is built around an STM32F4 microcontroller running at 168 MHz. This micro has a DCMI port to which a OV9650 camera is attached. The resolution ends up being 1280×1024, far better than other serial cameras.

Already [Ibrahim] has the hardware working and a few demo apps. He has a real time color tracking demo (video below) up and running and a machine vision repo for his tiny camera. Now if we could only get a few of these boards on Tindie.

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Retrotechtacular: Upgrading Train Signaling Before The Information Age

November 12, 2013 by 25 Comments

retrotechtacular-british-railway-signaling

What’s surprising about the subject of this week’s Retrotechtacular is that the subject is not from that long ago. But looking at the way in which the work was done makes it feel so far in the past. In 1974 the British Railways Board set out to modernize and interconnect the signaling system. What you see above is one of hundreds of old signal control houses slated to be replaced by an interconnected system.

These days we take this sort of thing for granted. But from the start of the project it’s clear how the technology available at the time limited the efficiency of the development process. We’re not talking about all of the electro-mechanical parts shown during the manufacturing part of the video. Nope, right off the bat the volumes of large-format paper schematics and logic diagrams seem daunting. Rooms full of engineers with stacks of bound planning documents feel alien to us since these days even having to print out a boarding pass seems antiquated.

With fantastic half-hour videos like this one available who needs television? We’d recommend adding this to your watch list so you can properly enjoy it. They show off everything; manufacturing the cables, stringing them between the signal towers, assembling the control panels, testing, and much more.

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Upstagram: A Flying Raspberry Pi

November 12, 2013 by 5 Comments

Upstagram Pre-flight

This tiny paper house, modeled after the one in Disney’s UP, contains a Raspberry Pi, battery pack, camera, and 3G stick. The Upstagram, built by the folks at HackerLoop, took to the skies of Paris to snap and share photos on Instagram.

We’ve seen Raspberry Pis in flight before, but this build pulls it off using simple party balloons. It took around 80 balloons to get the house to a height of 300 feet. A kite string was used to tether the device and control its flight.

This hack also required some reverse engineering of Instagram. Since the photo sharing service only allows the official Android and iOS apps to upload, they had to use a reverse engineered Instagram client. This allows the unsupported Raspberry Pi to interact with the service, snapping pictures periodically and sharing them on the device’s stream.

After the break, check out a quick video overview of the project.

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Wireless Keurig Hack!

November 12, 2013 by 15 Comments

coffeemaker

[Kolumkilli] loves his Keurig coffee maker, as it makes him an excellent cup of coffee, but he doesn’t like waiting for it to brew. So he set out to make it wirelessly controlled via his computer… with the press of a button, he can have his coffee ready and waiting for him when he gets up.

After carefully dismantling his Keurig, he set to locating the main buttons on the PCB, and proceeded to wire in relays in parallel to the ones he wanted to control. Throw in a Moteino and add the notification LEDs as inputs as well and now he can control and monitor almost all the coffee maker’s functions via a web browser at his desk. Now if only he could remember to put a new coffee cup in…

There’s a great writeup on the forum post, so if you want to see a more detailed build log, check it out! And if you’re looking to add even more functionality to your Keurig, why not run a waterline to it?

[Thanks Felix!]

Keep Your SD Cards Data Safe With The SD Locker

November 12, 2013 by 41 Comments

sdlocker_1

[Karl Lunt] has come up with a simple circuit for protecting data you have stored on SD cards. As is relatively well-known, the little lock switch on the side of most SD cards really doesn’t do anything more than the switch on floppies or the tabs on VHS or cassette decks. It’s up to the reader/writer to check the status of the tab and decide if it should write to the card or not. Not a very safe system. However, it’s not the only write protection system built into SD and SDHC cards. As part of the standard, cards have three protection methods: A TMP_WRITE_PROTECT bit, a PERM_WRITE_PROTECT bit, and a PWD register.

The PERM_WRITE_PROTECT bit permanently write protects the card. The bit can not be reset, so you should be really sure you want to keep the data on the card forever. The PWD register is a password register. The card will not allow any access (read or write) unless a password is provided. The TMP_WRITE_PROTECT bit is a temporary write protect. This is the bit that [Karl] is working with. When TMP_WRITE_PROTECT is set, the card can be read but not written. Note that there is no true protection here, as anyone can modify the bit. However, this should stop grandma from accidentally deleting your wedding pictures.

[Karl’s] device is very simple. A card is inserted into an Altoids tin enclosure. One button locks the card, another unlocks it. Three LEDs return status – power, card locked, and card unlocked. Under the hood, he’s using an Atmel ATmega328 to set and clear the TMP_WRITE_PROTECT bits. Power is provided by two AA batteries, and regulated with a Pololu 3.3v boost regulator. [Karl] has also included a serial port for control and debug information. We think this is a great hack, however one thing we’re not sure of is how or if these features are implemented in all cards. We’re relatively sure the name brand cards stick to the SD/SDHC spec sheet, but what about all the knockoff and no name brands from overseas?

Reverse Engineering The Sony Ericsson Vivaz High Resolution 640 X 360 Cellphone LCD

November 12, 2013 by 35 Comments

In our opinion, reverse engineering may be one of the best ways to tease your brain. [Andy] just did that by reverse engineering the Sony Ericsson Vivaz high resolution LCD (cached copy here). In his (very) nicely written article, [Andy] explains all the steps that led him to the result shown in the picture above. He started by finding the repair manual of the Vivaz, to discover that the display could be interfaced with 8080 type parallel signals. That meant that he could use a standard microcontroller without high speed buses to interface with it, in this case the STM32F4. Next in his adventure, [Andy] ordered the appropriate connector and took a more educated guess for the onboard microcontroller. A long Google search brought up the R61523 from Renesas. So he designed his breakout board, got it produced and a few hours later a nice picture was being shown on the LCD. He even took the time to compare the original display with the clone he found on the webs, and modified his graphics library to support this display.