Level Converters To Make All Your Hardware (5.5V And Under) Play With Each Other

December 11, 2012 by Mike Szczys 18 Comments

txb0108-level-converters-ks0108-stellaris-launchpad

I finally set aside some time for one of my own projects. I have been playing around with ARM microcontrollers a lot lately and wanted to try out my GLCD display that uses the KS0108 protocol. It’s 5V but I had heard that some of these displays will work with 3.3V TTL. But the datasheet tells me otherwise. I tried using a pull-up resistor to 5V and configuring the Stellaris Launchpad pins to open drain, but the low voltage wasn’t getting below the 0.3V threshold needed by my display. My only choice was to use some type of level conversion. I actually ended up driving the KS0108 using a pair of TXB0108 level converters.

I figured this had to have been done before so I check over at Sparkfun. Their offerings are either one-way or have a direction pin that you must drive yourself. I figured there had to be a bi-directional solution and a search over at Mouser led me to the TXB0108. It is exactly what I was looking for and as you can see I etched my own circuit boards to make the TSSOP chips breadboard compatible. I’ve documented the process you can find the code and board files at my post linked above.

Update: one of the Reddit comments mentions this chip is available on a breakout board from Adafruit if you’re interested.

Through Hole Plating And Milling At Home

November 29, 2012 by Mike Szczys 27 Comments

Here’s a PCB fabrication process that makes us envious. It’s pretty darn close to fab-house quality at home. [Cpirius] is using a CNC mill and through hole plating technique to produce his double-sided circuit boards.

The video embedded after the break shows one board from start to finish. It begins with the mill drilling holes through some double-sided copper clad stock. Once the millings have been cleaned off the holes are coated with a mixture of waterproof ink and carbon. This prepares them for plating by making the holes themselves conductive. The board is then run through an electroplating process based on this guide.

Possibly the most interesting part of the process starts 52 seconds into the clip. The mill uses a conductive probe to generate a height map of the entire board. This allows it to vary the routing depth for perfectly cut isolation traces. That final routing process is pictured above.

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MSP430 Launchpad Game Of Life Shield

November 19, 2012 by Mike Szczys 2 Comments

[100uf] built an LED matrix shield for the MSP430 launchpad. His goal with this design was to have it play Conway’s Game of Life. It does just that, as you can see in the clip after the break. But it’s just waiting to learn some more tricks. After he tires of watching the cellular automaton he can try his hand at making some LED pendant animations.

As you can tell, the board was made in his home workshop. It’s not etched, but milled using the CNC machine shown in this image gallery. This is a single-sided PCB, which works well enough for the surface mount components and the downward facing pin sockets. But we wonder how difficult it was to solder the legs of that 8×8 LED matrix. It does have plastic feet at each corner that serve as standoffs to separate the body from the copper layer. But it still looks like a tight space into which he needed to get his iron and some solder.

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Upverter 2.0 Launches

November 6, 2012 by Eric Evenchick 41 Comments

Disclosure: I currently work at Upverter

We’ve featured Upverter here in the past. At that time, the EDA tool was capable of collaborative schematic capture. Today, Upverter is launching version 2.0 of their tool which includes many new features allowing for end-to-end electronics design.

Upverter now has a PCB editor, allowing you to manufacture your designs. They are working with PCB manufacturers to make it easy to choose a fab and submit design files. Other new features include a Spice based simulation engine allowing in-browser simulation, and product lifecycle management features to help manage your project’s bill of materials.

When we last looked at Upverter, it was just a tool for creating and sharing schematics. With today’s launch, the tool can be used for designing electronics from start to finish. Since Upverter is free for open source projects, it will be interesting to see how hackers use it.

You can check out a tour of the new features. Any thoughts on using a cloud based EDA tool? Let us know in the comments.

Semi-professional Board Assembly For Your Workshop

October 29, 2012 by Mike Szczys 10 Comments

[Zach Hoeken] has the answer to assembling multiple surface mount PCBs in the home workshop. It’s certainly not for everyone. But if you’ve ever thought of marketing your own small runs he has the equipment and methodology you need.

He had tried using hacked together equipment, but after encountering a range of issues he finds the investment in a few key items saves time and money in the long run. The first is a precision tooling fixture block; that metal plate with a grid of holes that makes up the background of the image above. It comes with machined pegs which fit the holes perfectly, and as you can see, his panel of 16 boards include tooling holes that line up with the fixture. Once in place, a steel solder stencil is aligned with the board using its own tooling holes. The alignment of the stencil and its uniformed thickness ensure that the perfect amount of solder paste is easy to apply with a squeegee. [Zach] hand places his components but he did invest in a proper reflow oven to make the soldering a set and forget process.

Hackaday Links: October 18, 2012

October 18, 2012 by Mike Szczys 5 Comments

Capacitive touch plants

Here’s a proof of concept for using plants as a capacitive touch sensor. The sensor is simply a hunk of double-sided copper clad board attached to a microcontroller. But it seems to be able to sense what part of the plant is being touched. [Thanks Fabien]

Adding wireless charging to a Nokia N900

This hack is quite common, but it’s still fun to see what hardware is being outfitted with an inductive charger. This time it’s a Nokia N900 that’s ditching the charging cables.

Wii carrying suitcase from a plastic tackle box

This Wii carrying case (translated) looks great and cost just a few bucks. It started as a tackle box for carrying around your fishing lures. But a bit of creative cutting and there’s a place for everything.

Browser based schematic and board layout

There’s a new kid on the block when it comes to circuit design. Circuits.io offers in-brower schematic design and board artwork layout. [Thanks ADIDAIllinie (and a few others)]

Bender-o-lantern

Halloween rapidly approaches and we hope that [Tim’s] carving of Bender in a pumpkin will inspire you to send in your own Halloween projects.

How To Repair A Ribbon Cable Connection On Consumer Electronics

September 20, 2012 by Mike Szczys 34 Comments

It’s not uncommon in cheaper devices to find a ribbon cable soldered directly to the circuit board like the one pictured above. Using a connector would have been a much more resilient approach, but adding parts adds cost. If you take a close look you’ll see things aren’t looking so great anymore. [Chaotic and Random] pulled this board out of his VW Camper Van. Rather than buy an expensive replacement part, he shows us how to repair a soldered ribbon wire connection.

This repair is rather invasive and he suggests trying some hot-air rework (possibly using a heat gun) to fix up any misbehaving connections. But if that has failed it’s time for the knife. The first step is to cut the ribbon so that the LCD can be removed from the board. From there he peels the remaining scrap off ribbon of the pads. This makes us cringe as it could lift traces from the PCB, but he was gentle enough to avoid it. Now comes the time to start reassembling. After thoroughly cleaning the pads the ribbon is cut straight and resoldered. The trick is to flow the solder without melting the ribbon. He uses tin foil to cover the tip and cools it on a moist sponge just before reflowing solder.

It sounds like more art than science. But when the only alternative is to spend hundreds on a new part it may be worth a try.