The Catweazle Mini: A Super Small ARM Based Embedded Platform

Catweazle

There has been a recent trend in miniaturizing embedded platforms. [Jan] wrote in to tell us about his very tiny ARM based embedded platform, the Catweazle Mini. Who knew that an ARM based system could be so simple and so small?!?

With the success of the Trinket and Femtoduino (miniature Arduino compatible boards) and many other KickStarter campaigns, it is only natural for there to be a mini platform based on the ARM architecture. Built around the NXP LPC810 ARM Cortex M0+ MCU at 30MHz (which only costs slightly more than $1, by the way), this small embedded platform packs some pretty impressive processing power. The board contains a simple linear regulator, and can be programmed via UART. [Jan's] development environment of choice is the mbed compiler, which is free and requires no installation. If you need some help getting started Adafruit has a nice guide for the LPC810.

Do you need some more processing power for your next wearable project? Be sure to use the Catweazle Mini.

USB connectivity that is so very very small

Using FTDI chips as a USB to Serial solution is nothing new, but this MicroFTX board takes the footprint to a new low. If you’re space limited this should have no problem fitting into your project. But if you plan to use it for prototyping we predict it’ll be lost in the parts bin forever as soon as you take your eyes off of it.

The USB Mini-B connector is becoming quite popular with hobby electronics these days. But here [Jim Paris] chose to use its little brother, the USB micro connector. Want to put this together by hand? How are you with 0402 footprints and QFN chips? In fact, there’s a ground pad on the bottom of that IC which means you really need to use a reflow oven to do the job right.

Aside from the diy-unfriendly fabrication size, we do like the design. There are four output pins (voltage, ground, TX, and RX) with a set of four solder jumpers to configure them. It can be powered from the USB port or an external connection, with the option for 5V or 3.3V output.

[Thanks John]

Making a smaller keyboard

The keyboard on [Marek's] laptop stopped working. He didn’t want to buy a replacement so he decided to start using an external keyboard. But hauling around a full 104-key model is a bit of a pain so he decided to make himself a shorter keyboard. He basically chopped off the 10-key pad on the right side of the board. This had the unexpected consequence of removing the screws that hold the top and bottom of the case together so he ended up adding a few extra screws to shore it up. You may be wondering how the key matrix still works if a portion of it has been cut off. [Marek] used the simple trick of folding the extra part of the membrane over and covering the unused contacts with some tape.

If you try this you should consider getting rid of the directional arrows and editing keys as well. There must be a way to map those keys elsewhere. Perhaps the half-qwerty keyboard hack will give you some inspiration for that.

Miniscule intervalometer

Calling this intervalomemter small would be a glaring understatement. It’s tiny enough to fit inside the plastic cover for a 2.5mm jack for use with a Canon DSLR camera. We should point out that the image we put together is a bit misleading. The picture of the jack is version 1 of this circuit and uses an 8-pin SOIC chip. The board in the oval is version 2, with a PIC 10f222 SOT23-6 package making it even smaller than the original version.

This is used for time-lapse photography. When plugged in the chip draws power from the camera. Get this: it learns the timing interval by listening for the first two images. Once you’ve snapped the first two pictures the PIC will continue to take images based on that initial delay. Amazing.

[Thanks AW via DIY Photography]

Tiniest bot, sort of. CNC controlled

tinybot

Here’s an interesting concept, the bot pictured above has no internal control mechanisms.  His claims to have built the smallest bot are dubious, considering it requires a much larger control platform to function, so lets just set that aside and look at how it works. The bot itself is basically a hollow box with a hinged manipulator mounted on it. He has then built a modified CNC type structure with various magnets below a platform. The magnets can move the bot and control the manipulator (assuming the bot isn’t trying to pick up anything magnetic). He talks about this being a possible control scheme for smaller bots, though we think he would have to make some major advancements to his magnetic controls for accuracy’s sake. As for his claims of being the smallest, well, we’re sure we’ve seem similarly sized bots, even hexapods,  that were completely self contained.

Microbot for the Robocup 2008

[tioguerra] helped make these tiny bots for the World Robocup 2008 in china. There’s tons of information on the Mixed Reality forum, but you might be specifically interested in the bot section.  There are breakdowns of different aspects, such as charging and IR communication, as well as some great photographs of the unit along with a smaller one. The construction of the robot seems so nicely fit together, someone spent a lot of time getting the design just right.  Since we don’t see a new section for 2009 bots, we are guessing that they’ll use this design again.