Spin a PCB for Your Most Beloved Sensors

sensorstick-breakout

If you follow [Ioannis'] lead you’re going to thank yourself every time you sit down to work on a new prototype. He took all of the sensors which he most commonly uses and spun one dev board to host them all.

As long as you’re willing to wait for delivery, the cost of small-run professionally made PCBs has become unbelievably reasonable. That’s really nice when you need to test your layout before exploring larger production. But it also means you can develop your own dirt-cheap yet reliable dev tools. This example combines three sensors which all communicate via I2C:

  • MPU6050 accelermoter/gyro
  • BMP085 pressure sensor
  • SHT10 humidity sensor

Obviously this is a great idea, but key is the cheat sheet which [Ioannis] included on the bottom of the board. It testifies as to which chips are on the board, but also includes the device addresses for the data bus. We’ve adopted the mantra that if a breadboarded prototype is not working, it’s always a hardware problem. For those oft-used parts this should alleviate some of the heartache at your bench.

You could still make something like this without spinning or etching a board. You’ll just have to be creative with the soldering.

Hackaday Links: March 23, 2014

hackaday-links-chain

[Jack] sent us a link to a Metropolitan Museum of Art video showing off a mechanized desk that plays music and has a ton of hidden compartments. Furniture makers of yore built hidden compartments in furniture all the time. After all, there weren’t credit cards back in the day and you had to keep important documents, cash, and everything else on hand. What strikes us is that this mates woodworking of the highest caliber with precision mechanics.

Before you get rid of that old box spring, ask yourself if you need to store dimensional goods. If you rip off the outer fabric, the network of wire inside makes a reasonable lumber rack.

And since we’re talking trash, we enjoyed seeing this water bottle wire spool minder which [Daniel] sent our way.

You know those portable DVD players you can hang from a headrest to entertain the kids on long trips? Well [John's] broke, and like chasing the dragon, once you’re hooked on watching videos during car trips there’s no going back. Luckily he was able to throw a Raspberry Pi at the problem. He now has a portable OpenElec XBMC device controlled via a smartphone.

[Jaromir] posted some breakout board footprints that you can use. It’s not the footprints that impress us, but the idea of using them to fill up board space when spinning a new PCB. [Thanks Sarah]

LEGO Gachapon. Need we say more? Okay, truth be told we had to look it up too; Wikipedia says it’s spelled Gashapon. These are coin-operated machines that dispense toys inside of plastic capsules. This one’s made of LEGO and it’s awesome.

[Mikhail] actually built his own ballast resistors for some HeNe laser tubes. This is a bit easier than it might sound at first, as they are much lower power than the tubes used in cutters. But none-the-less an interesting, and successful, experiment.

Breakout board for $11 LCD module with small pitch

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[Ibrahim] picked this little LCD module out because of its price point and resolution. In single units you can grab one of the 128×32 pixel displays for just $11. The only problem is that the pinout is too small to use with a breadboard. He whipped up a breakout board for it that throws in some extras.

First off, we like it that the board doesn’t add much to the part’s outline. What it does add is a Low-DropOut voltage regulator and a level converter. The upper range of the LCD’s input voltage is 3.3V, and these added parts make it possible to drive the device using 5V hardware like the Arduino Uno pictured above. While he was adding in parts he included a MOSFET to switch the backlight. This way he can use PWM for dimming as well.

We usually hit eBay when looking for LCD screens. A search for the NHD-C12832 part number didn’t turn it up. We tried out FindChips for the first time (owned by Supply Frame who just bought Hackaday) and it works just as well as Octopart which we’re more familiar with since we’ve seen some hacking of that site before.

Solder trick to make your own surface mount breakout boards

surface-mount-breakout-trick

We think you’re really going to enjoy this trick for making surface mount breakout boards. It’s common to use magnet wire to connect individual pins of a surface mount part to breadboard friendly protoboard with pin headers. What’s new here (at least to us) is that [Raul] solders one wire to both pins directly across from one another.

The image at the left shows an eight pin part with four wires soldered in place. To get to this point he first taped the wires down to a work surface being careful to space them to match the pitch on the chip’s leads. He then tapes the chip in place and solders all of the legs to the wires. This seems to kill two birds with one stone as aligning one wire to one leg is tough. From there he flips the chip over and cuts the wire spanning under it. This leaves an easy job of soldering the trailing side of the wire to a hunk of protoboard.

It’s perfect for chips with a small number of pins. Of course you may still want an etched breakout board for something with a ton of leads.

Hand soldering BGA parts should be a circus act

Okay, we think it’s questionable when people say they have no problem soldering QFN packages, but BGA? Granted this chip has far fewer balls on it than many, but it’s still quite impressive that [Xevel] was able to solder this BGA breakout by hand.

The chip you see above is a TMP006 infrared temperature sensor from TI. [Xevel] picked up the part but didn’t want to break the bank when prototyping by buying a proper PCB to host it. There are only eight conductors on it, arranged in a grid with 0.5mm pitch. That didn’t seem to scare him off, as the video after the break shows him connecting each to a conductor on a hunk of stripboard.

[Xevel] mentions that this is a dead-bug style project. Usually you glue the part upside down when using that technique, but it needs line of sight to get an accurate temperature reading so he first cut a hole in the substrate. We’d bet he’s using wire-wrapping wire to make the connections. It’s a very fine solid core wire which is perfect for this kind of work.

[Read more...]

PIC 18F4550 dev board

[Natsfr] was looking for a single-sided PCB to host a PIC 18F4550. Not finding one he designed his own in Kicad and is sharing (translated) the spoils of his labor.

This chip has USB capabilities which is why we see it used in a ton of projects. Almost all of them (including this USB input device post) use a very large DIP package. [Natsfr] went a different route, designing for the TQFP package to keep the drilling ot a minimum. The layout includes a crystal and USB-mini port, but it also breaks out the I/O pins on the chip. The red box above shows the quick fix he used on the VCC line as the board trace was shorting on the USB jack housing.

He didn’t drill out the holes for most of the breakout pins on this prototype. There’s just one header populated for programming the PIC chip. But he does have some plans for the first board. He’s going to use [Texan's] AVR programming firmware for PIC to turn it into a USB AVR ISP programmer.

Prototyping with very, very small ICs

Gone are the days when all the cool chips are able to be thrown into a breadboard very easily. [starlino] was working with a circuit that uses an accelerometer, but unfortunately these chips come in hard to solder LGA-16 packages. [starlino] figured out a way to prototype with these packages that doesn’t require a custom breakout board or spending any time watching a reflow oven.

[starlino]‘s LGA-16 adapter board began with a piece of perf board drilled out to form a space that perfectly fits his accelerometer. A piece of tape is placed over the pads of the chip and perf board, and the gap between the chip and board is filled in with a two-part plumbers putty.

Once the putty has cured, the leads on the acclerometer are connected to the pads on the board with a silver conductive pen. After putting a few header pins in the corners of the board, [starlino] soldered the pads to the pins and had a permanent breakout board for a very small accelerometer.

It’s not by any means a pretty build, but after [starlino] sealed the entire build in liquid electrical tape and installed it in a DIP socket, he had a completely functional accelerometer in an easy to prototype package. Not bad for a breakout board that can be built from stuff just lying around a workbench.